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四氢呋喃是一类杂环有机化合物。
它是强的极性醚类之一，在化学反应和萃取时用做一种中等极性的溶剂。
无色易挥发液体，有类似乙醚的气味。
溶于水、乙醇、乙醚、丙酮、苯等多数有机溶剂。
CAS号：109-99-9产品中文名：四氢呋喃产品英文名：tetrahydrofuranTitle: TetrahydrofuranCAS Registry Number: 109-99-9Additional Names: Diethylene oxide; tetramethylene oxideMolecular Formula: C4H8OMolecular Weight: 72.11Percent Composition: C 66.62%, H 11.18%, O 22.19%Literature References: Prepn from 1,4-butanediol: Schmoyer, Case, Nature 187, 592 (1960). Manuf by catalytic hydrogenation of maleic anhydride: Gilbert, Howk, US 2772293 (1956 to du Pont); of furan: Banford, Manes, US 2846449 (1958 to du Pont); Manly, US 3021342 (1962 to Quaker Oats). Stabilization to prevent excessive peroxide formation on storage with 0.05-1.0% p-cresol, 0.05-0.1% hydroquinone, or less than 0.01-0.1% 4,4¢-thiobis(6-tert-butyl-m-cresol): Bordner, Hinegardner, US 2489260; US 2525410; Campbell, US 3029257 (1949, 1950, 1962 all to du Pont). Review of toxicology and biological effects: D. E. Moody, Drug Chem. Toxicol. 14, 319-342 (1991).Properties: Liquid. Ether-like odor. mp -108.5°. d420 0.8892. bp760 66°; bp176 25°. Flash pt 1°F. nD20 1.4070. Dipole moment: 1.70. uv cut-off for spectro grade: 220 nm. Miscible with water, alcohols, ketones, esters, ethers, and hydrocarbons. Caution: Distil only in presence of a reducing agent, such as ferrous sulfate; peroxide explosions have occurred: Angew. Chem. 68, 182 (1956).Melting point: mp -108.5°Boiling point: bp760 66°; bp176 25°Flash point: Flash pt 1°FIndex of refraction: nD20 1.4070Density: d420 0.8892CAUTION: Potential symptoms of overexposure are irritation of eyes and upper respiratory system; nausea, dizziness and headache; CNS depression. See NIOSHPocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 302.Use: Solvent for high polymers, esp polyvinyl chloride. As reaction medium for Grignard and metal hydride reactions. In the synthesis of butyrolactone, succinic acid, 1,4-butanediol diacetate. Solvent in histological techniques. May be used under Federal Food, Drug & Cosmetic Act for fabrication of articles for packaging, transporting, or storing of foods if residual amount does not exceed 1.5% of the film: Fed. Regist. 27, 3919 (Apr. 25, 1962).网化商城危险提示：防范说明：P210 远离热源/火花/明火/热表面。
马来酸酐接枝ABS 及其应用陈玉胜张祥福张勇张隐西(上海交通大学高分子材料研究所,上海200240摘要采用熔融法研究了马来酸酐(M AH 接枝ABS 。
结果表明:马来酸酐接枝率随M AH 添加量或引发剂过氧化二异丙苯(DCP 的添加量的增加而提高,但是添加量过多时,接技率增加速率变慢;ABS 接枝马来酸酐后,冲击性能明显下降,但拉伸性能变化不大;马来酸酐接枝改性ABS ,增容ABS/PC 合金共混物,可提高合金的缺口抗冲击强度达1.5~2.5倍。
关键词:马来酸酐接枝丙烯睛/丁二烯/苯乙烯共聚物增容聚碳酸酯0前言收稿日期:2000201204在共混中采用反应增容方法促进溶解度参数不匹配的聚合物共混,已越来越受到人们关注。
这种方法的本质特性是在加工过程中使共混组分之间发生化学反应,生成接枝或嵌段聚合物,该聚合物作为共混增容剂使组分间良好地分散和增强界面结合[1]。
因此这种方法最基本的要求是共混聚合物组分分子链中应含具有反应活性的功能基团,如环氧基团、酸酐基团、磺酸基团等。
这些基团的特点是与氨基、羟基等基团的反应活性高,并且无低分子物生成。
ABS 是通用工程塑料,综合性能好,常与其它聚合物共混制备合金。
在与其它聚合物(如尼龙、聚碳酸酯共混过程中,ABS 与它们之间的相容性是合金获得优良综合性能的关键。
国内外已有报道采用马来酸酐接枝改性ABS 作为增容剂,用以改善ABS 系列合金间的相容性[2,3]。
本研究在H AAKE 转矩流变仪上,采用马来酸酐熔融接枝改性ABS ,考察了影响接枝反应的主要因素、接枝产物力学性能变化以及接枝产物增容ABS/PC 合金的应用前景。
1实验部分1.1原料ABS 树脂,牌号PA -747S ,台湾奇美实业股份有限公司产品;PC 树脂,Lexan141,美国GE 塑料树脂(中国公司产品,马来酸酐(M AH ,化学纯,上海山海科技研究所;过氧化二异丙苯(DCP :化学纯。
其中PC 、ABS 树脂在使用前均在90℃干燥8h ,以除去吸收的水分1.2主要仪器和设备转距流变仪,H AAKE RC -90型,德国H AAKE 公司;双螺杆挤出机,SH L -35型,上海化工机械四厂;红外光谱仪,Perkin -Elmer 1000型,美第14卷第5期2000年5月中国塑料CHINA P LASTICSV ol14N o 5May 2000国PE公司;万能冲击试验机RAY-RAN2500,英国RAY-RAN公司。
362021年第2期（3）微米铝粉中加入10%左右的纳米铝粉，可以获得最大爆炸压力和压力上升速率，分析认为主要原因是高反应活性的纳米铝粉对爆炸体系进行了敏化，提高了粉尘的爆炸剧烈程度。
参考文献：[1]李庆钊,王可,梅晓凝,等.微米级铝粉的爆炸特性及其反应机理研究[J].工程热物理学报,2017,38(1):219-225.[2]K Balakrishnan.,A L Kuhl.,J B Bell.,V E Beckner.Anempirical model for the ignition of explosively dispersed aluminum particle clouds[J].Shock Waves,2012(22):591-603.[3]KWON Y S,GROMO A A,ILYIN A P,et al..Themechanism of combustion of superfine aluminum powders[J].Combustion and Flame,2003,133(4):385-391.[4]GROMOV A,VERESHCHAGIN V.Study of aluminumnitride formation combustion by superfine aluminum powder combustion in air[J].Journal of the European Ceramic Soeiety, 2004,24(9):287-288.[5]ZHOU Jing,AN Jing,et al..Thermal behaviors of the maincomponents in nana-based fuel air explosive[J].Chinese Journal of Explosives&Propellants,2017,40(3):31-35. [6]尉存娟,谭迎新.铝粉-空气混合物爆炸压力影响因素研究[J].火工品,2009(2):31-34.[7]周卫军,王少龙,等.铝粉对FAE爆轰性能影响的研究[J].战术导弹技术,2008(1):14-16.[8]陈晓坤,张自军,等.20L近球形容器中微米级铝粉的爆炸特性[J].爆炸与冲击,2018,38(5):1130-1136.[9]Supri A.G.,Ismail H.,Shuhadah S.Effect of polyethylene-grafted maleic anhydride(PE-g-MAH)on properties of low density polyethylene/eggshell powder(LDPE/ESP)composites [J].Journal of Macromolecular Science:Part D-Reviews in Polymer Processing,2010,49(4):347-353.[10]Tan S.J.,Supri A.G.,Teh P.L..Effect of PE-g-MAH ascompatibilizer on properties of ldpe/nr/whf composites[J].Applied Mechanics and Materials,2013(284-287):87-93. [11]Yang J N,Nie S B.Effects of calcium sulfate whisker on themechanical property,morphological structure and thermal degradation of poly(lactic acid)composites[J].Polymer Degradation and Stability,2017(144):270-280.[12]陈雄胜.导爆管性能测试研究[J].爆破器材,2015,44(3):48-50.[13]Kissinger HE.Reaction kinetics in differential thermal analysis[J].Anal Chem,1957,29(11):1702-1706.[14]Carrasco F,Pagès P,Gámez-Pérez J,et al..Kinetics of thethermal decomposition of processed poly(lactic acid)[J].Polym Degrad Stab,2010,95(12):2508-2514.《火工品》期刊再次入选《中文核心期刊要目总览》据《中文核心期刊要目总览》2020版编委会通知：《火工品》期刊入选《中文核心期刊要目总览》2020年版（第9版）之武器工业类核心期刊。
纳米二氧化硅对成核、结晶和热塑性能的影响外文文献翻译(含：英文原文及中文译文)文献出处：Laoutid F, Estrada E, Michell R M, et al. The influence of nanosilica on the nucleation, crystallization andtensile properties of PP–PC and PP–PA blends[J]. Polymer, 2013, 54(15):3982-3993.英文原文The influence of nanosilica on the nucleation, crystallization andtensileproperties of PP–PC and PP–PA blendsLaoutid F, Estrada E, Michell R M, et alAbstractImmiscible blends of 80 wt% polypropylene (PP) with 20 wt% polyamide (PA) or polycarbonate (PC) were prepared by melt mixing with or without the addition of 5% nanosilica. The nanosilica produced a strong reduction of the disperse phase droplet size, because of its preferential placement at the interface, as demonstrated by TEM. Polarized Light Optical microscopy (PLOM) showed that adding PA, PC or combinations of PA-SiO2 or PC-SiO2 affected the nucleation density of PP. PA droplets can nucleate PP under isothermal conditions producing a higher nucleation density than the addition of PC or PC-SiO2. PLOM was found to be more sensitive to determine differences in nucleation than non-isothermal DSC. PP developed spherulites, whose growth was unaffected by blending, while its overall isothermal crystallizationkinetics was strongly influenced by nucleation effects caused by blending. Addition of nanosilica resulted in an enhancement of the strain at break of PP-PC blends whereas it was observed to weaken PP-PA blends. Keywords：Nanosilica，Nucleation，PP blends1 OverviewImmiscible polymer blends have attracted attention for decades because of their potential application as a simple route to tailor polymer properties. The tension is in two immiscible polymerization stages. This effect usually produces a transfer phase between the pressures that may allow the size of the dispersed phase to be allowed, leading to improved mixing performance.Block copolymers and graft copolymers, as well as some functional polymers. For example, maleic anhydride grafted polyolefins act as compatibilizers in both chemical affinities. They can reduce the droplet volume at the interface by preventing the two polymers from coalescing. In recent years, various studies have emphasized that nanofillers, such as clay carbon nanotubes and silica, can be used as a substitute for organic solubilizers for incompatible polymer morphology-stabilized blends. In addition, in some cases, nanoparticles in combination with other solubilizers promote nanoparticle interface position.The use of solid particle-stabilized emulsions was first discovered in 1907 by Pickering in the case of oil/emulsion containing colloidalparticles. In the production of so-called "Pickling emulsions", solid nanoparticles can be trapped in the interfacial tension between the two immiscible liquids.Some studies have attempted to infer the results of blending with colloidal emulsion polymer blends. Wellman et al. showed that nanosilica particles can be used to inhibit coalescence in poly(dimethylsiloxane)/polyisobutylene polymers. mix. Elias et al. reported that high-temperature silicon nanoparticles can migrate under certain conditions. The polypropylene/polystyrene and PP/polyvinyl acetate blend interfaces form a mechanical barrier to prevent coalescence and reduce the size of the disperse phase.In contrast to the above copolymers and functionalized polymers, the nanoparticles are stable at the interface due to their dual chemical nature. For example, silica can affect nanoparticle-polymer affinities locally, minimizing the total free energy that develops toward the system.The nanofiller is preferentially placed in equilibrium and the wetting parameters can be predicted and calculated. The difference in the interfacial tension between the polymer and the nanoparticles depends on the situation. The free-diffusion of the nanoparticle, which induces the nanoparticles and the dispersed polymer, occurs during the high shear process and shows that the limitation of the viscosity of the polymer hardly affects the Brownian motion.As a result, nanoparticles will exhibit strong affinity at the local interface due to viscosity and diffusion issues. Block copolymers need to chemically target a particular polymer to the nanoparticle may provide a "more generic" way to stabilize the two-phase system.Incorporation of nanosilica may also affect the performance of other blends. To improve the distribution and dispersion of the second stage, mixing can produce rheological and material mechanical properties. Silica particles can also act as nucleating agents to influence the crystallization behavior. One studies the effect of crystalline silica on crystalline polystyrene filled with polybutylene terephthalate (polybutylene terephthalate) fibers. They found a stable fibril crystallization rate by increasing the content of polybutylene terephthalate and silica. On the other hand, no significant change in the melt crystallization temperature of the PA was found in the PA/ABS/SiO2 nanocomposites.The blending of PP with engineering plastics, such as polyesters, polyamides, and polycarbonates, may be a useful way to improve PP properties. That is, improving thermal stability, increasing stiffness, improving processability, surface finish, and dyeability. The surface-integrated nano-silica heat-generating morphologies require hybrid compatibilization for the 80/20 weight ratio of the thermal and tensile properties of the blended polyamide and polypropylene (increasedperformance). Before this work, some studies [22] that is, PA is the main component). This indicates that the interfacially constrained hydrophobic silica nanoparticles obstruct the dispersed phase; from the polymer and allowing a refinement of morphology, reducing the mixing scale can improve the tensile properties of the mixture.The main objective of the present study was to investigate the effect of nanosilica alone on the morphological, crystalline, and tensile properties of mixtures of nanosilica alone (for mixed phases with polypropylene as a matrix and ester as a filler. In particular, PA/PC or PA/nano The effect of SiO 2 and PC/nanosilica on the nucleation and crystallization effects of PP as the main component.We were able to study the determination of the nucleation kinetics of PP and the growth kinetics of the particles by means of polarization optical microscopy. DSC measures the overall crystallization kinetics.Therefore, a more detailed assessment of the nucleation and spherulite growth of PP was performed, however, the effect of nanosilica added in the second stage was not determined. The result was Akemi and Hoffman. And Huffman's crystal theory is reasonable.2 test phase2.1 Raw materialsThe polymer used in this study was a commercial product: isotactic polypropylene came from a homopolymer of polypropylene. The Frenchformula (B10FB melt flow index 2.16Kg = 15.6g / 10min at 240 °C) nylon 6 from DSM engineering plastics, Netherlands (Agulon Fahrenheit temperature 136 °C, melt flow index 240 °C 2.16kg = 5.75g / 10min ) Polycarbonate used the production waste of automotive headlamps, its melt flow index = 5g / 10min at 240 °C and 2.16kg.The silica powder TS530 is from Cabot, Belgium (about 225 m/g average particle (bone grain) about 200-300 nm in length, later called silica is a hydrophobic silica synthesis of hexamethyldisilane by gas phase synthesis. Reacts with silanols on the surface of the particles.2.2 ProcessingPP_PA and PP-PC blends and nanocomposites were hot melt mixed in a rotating twin screw extruder. Extrusion temperatures range from 180 to 240 °C. The surfaces of PP, PA, and PC were vacuumized at 80°C and the polymer powder was mixed into the silica particles. The formed particles were injected into a standard tensile specimen forming machine at 240C (3 mm thickness of D638 in the American Society for Testing Materials). Prior to injection molding, all the spherulites were in a dehumidified vacuum furnace (at a temperature of 80°C overnight). The molding temperature was 30°C. The mold was cooled by water circulation. The mixture of this combination is shown in the table.2.3 Feature Description2.31 Temperature Performance TestA PerkineElmer DSC diamond volume thermal analysis of nanocomposites. The weight of the sample is approximately 5 mg and the scanning speed is 20 °C/min during cooling and heating. The heating history was eliminated, keeping the sample at high temperature (20°C above the melting point) for three minutes. Study the sample's ultra-high purity nitrogen and calibrate the instrument with indium and tin standards.For high temperature crystallization experiments, the sample cooling rate is 60°C/min from the melt directly to the crystal reaching the temperature. The sample is still three times longer than the half-crystallization time of Tc. The procedure was deduced by Lorenzo et al. [24] afterwards.2.3.2 Structural CharacterizationScanning electron microscopy (SEM) was performed at 10 kV using a JEOL JSM 6100 device. Samples were prepared by gold plating after fracture at low temperature. Transmission electron microscopy (TEM) micrographs with a Philips cm100 device using 100 kV accelerating voltage. Ultra-low cut resection of the sample was prepared for cutting (Leica Orma).Wide-Angle X-Ray Diffraction Analysis The single-line, Fourier-type, line-type, refinement analysis data were collected using a BRUKER D8 diffractometer with copper Kα radiation (λ = 1.5405A).Scatter angles range from 10o to 25°. With a rotary step sweep 0.01° 2θ and the step time is 0.07s. Measurements are performed on the injection molded disc.This superstructure morphology and observation of spherulite growth was observed using a Leica DM2500P polarized light optical microscope (PLOM) equipped with a Linkam, TP91 thermal stage sample melted in order to eliminate thermal history after; temperature reduction of TC allowed isothermal crystallization to occur from the melt. The form is recorded with a Leica DFC280 digital camera. A sensitive red plate can also be used to enhance contrast and determine the birefringence of the symbol.2.3.3 Mechanical AnalysisTensile tests were carried out to measure the stretch rate at 10 mm/min through a Lloyd LR 10 K stretch bench press. All specimens were subjected to mechanical tests for 20 ± 2 °C and 50 ± 3% relative humidity for at least 48 hours before use. Measurements are averaged over six times.3 results3.1 Characterization by Electron MicroscopyIt is expected that PP will not be mixed with PC, PA because of their different chemical properties (polar PP and polar PC, PA) blends with 80 wt% of PP, and the droplets and matrix of PA and PC are expectedmorphologies [ 1-4] The mixture actually observed through the SEM (see Figures 1 a and b).In fact, because the two components have different polar mixtures that result in the formation of an unstable morphology, it tends to macroscopic phase separation, which allows the system to reduce its total free energy. During shearing during melting, PA or PP is slightly mixed, deformed and elongated to produce unstable slender structures that decompose into smaller spherical nodules and coalesce to form larger droplets (droplets are neat in total The size of the blend is 1 ~ 4mm.) Scanning electron microscopy pictures and PP-PC hybrid PP-PA neat and clean display left through the particle removal at cryogenic temperatures showing typical lack of interfacial adhesion of the immiscible polymer blend.The addition of 5% by weight of hydrophobic silica to the LED is a powerful blend of reduced size of the disperse phase, as can be observed in Figures 1c and D. It is worth noting that most of the dispersed phase droplets are within the submicron range of internal size. The addition of nano-SiO 2 to PA or PC produces finer dispersion in the PP matrix.From the positional morphology results, we can see this dramatic change and the preferential accumulation at the interface of silica nanoparticles, which can be clearly seen in FIG. 2 . PP, PA part of the silicon is also dispersed in the PP matrix. It can be speculated that thisformation of interphase nanoparticles accumulates around the barrier of the secondary phase of the LED, thus mainly forming smaller particles [13, 14, 19, 22]. According to fenouillot et al. [19] Nanoparticles are mixed in a polymer like an emulsifier; in the end they will stably mix. In addition, the preferential location in the interval is due to two dynamic and thermodynamic factors. Nanoparticles are transferred to the preferential phase, and then they will accumulate in the interphase and the final migration process will be completed. Another option is that there isn't a single phase of optimization and the nanoparticles will be set permanently in phase. In the current situation, according to Figure 2, the page is a preferential phase and is expected to have polar properties in it.3.2 Wide-angle x-ray diffractionThe polymer and silica incorporate a small amount of nanoparticles to modify some of the macroscopic properties of the material and the triggered crystal structure of PP. The WAXD experiment was performed to evaluate the effect of the incorporation of silica on the crystalline structure of the mixed PP.Isotactic polypropylene (PP) has three crystalline forms: monoclinic, hexagonal, and orthorhombic [25], and the nature of the mechanical polymer depends on the presence of these crystalline forms. The metastable B form is attractive because of its unusual performance characteristics, including improved impact strength and elongation atbreak.The figure shows a common form of injection molding of the original PP crystal, reflecting the appearance at 2θ = 14.0, 16.6, 18.3, 21.0 and 21.7 corresponding to (110), (040), (130), (111) and (131) The face is an α-ipp.20% of the PA incorporation into PP affects the recrystallization of the crystal structure appearing at 2θ = 15.9 °. The corresponding (300) surface of the β-iPP crystal appears a certain number of β-phases that can be triggered by the nucleation activity of the PA phase in PP (see evidence The following nucleation) is the first in the crystalline blend of PA6 due to its higher crystallization temperature. In fact, Garbarczyk et al. [26] The proposed surface solidification caused by local shear melts the surface of PA6 and PP and forms during the injection process, promoting the formation of β_iPP. According to quantitative parameters, KX (Equation (1)), which is commonly used to evaluate the amount of B-crystallites in PP including one and B, the crystal structure of β-PP has 20% PP_PA (110), H(040) and Blends of H (130) heights (110), (040) and (130). The height at H (300) (300) for type A peaks.However, the B characteristic of 5 wt% silica nanoparticles incorporated into the same hybrid LED eliminates reflection and reflection a-ipp retention characteristics. As will be seen below, the combination of PA and nanosilica induces the most effective nucleatingeffect of PP, and according to towaxd, this crystal formation corresponds to one PP structure completely.The strong reductive fracture strain observations when incorporated into polypropylene and silica nanoparticles (see below) cannot be correlated to the PP crystal structure. In fact, the two original PP and PP_PA_SiO2 hybrids contain α_PP but the original PP has a very high form of failure when the strain value.On the other hand, PP-PC and PP-PC-Sio 2 blends, through their WAXD model, can be proven to contain only one -PP form, which is a ductile material.3.3 Polarized Optical Microscopy (PLOM)To further investigate the effect of the addition of two PAs, the crystallization behavior of PC and silica nanoparticles on PP, the X-ray diffraction analysis of its crystalline structure of PP supplements the study of quantitative blends by using isothermal kinetic conditions under a polarizing microscope. The effect of the composition on the nucleation activity of PP spherulite growth._Polypropylene nucleation activityThe nucleation activity of a polymer sample depends on the heterogeneity in the number and nature of the samples. The second stage is usually a factor in the increase in nucleation density.Figure 4 shows two isothermal crystallization temperatures for thePP nucleation kinetics data. This assumes that each PP spherulite nucleates in a central heterogeneity. Therefore, the number of nascent spherulites is equal to the number of active isomerous nuclear pages, only the nucleus, PP-generated spherulites can be counted, and PP spherulites are easily detected. To, while the PA or PC phases are easily identifiable because they are secondary phases that are dispersed into droplets.At higher temperatures (Fig. 4a), only the PP blend inside is crystallized, although the crystals are still neat PP amorphous at the observed time. This fact indicates that the second stage of the increase has been able to produce PP 144 °C. It is impossible to repeat the porous experiment in the time of some non-homogeneous nucleation events and neat PP exploration.The mixed PP-PC and PP-PC-SiO 2 exhibited relatively low core densities at 144 °C, (3 105 and 3 106 nuc/cm 3) suggesting that either PC nanosilica can also be considered as good shape Nuclear agent is used here for PP.On the other hand, PA, himself, has produced a sporadic increase in the number of nucleating events in PP compared to pure PP, especially in the longer crystallization time (>1000 seconds). In the case of the PP-PA _Sio 2 blend, the heterogeneous nucleation of PP is by far the largest of all sample inspections. All the two stages of the nucleating agent combined with PA and silica are best employed in this work.In order to observe the nucleation of pure PP, a lower crystallization temperature was used. In this case, observations at higher temperatures found a trend that was roughly similar. The neat PP and PP-PC blends have small nucleation densities in the PP-PC-SiO 2 nanocomposite and the increase also adds further PP-PA blends. The very large number of PP isoforms was rapidly activated at 135°C in the PP-PA nanoparticle nanometer SiO 2 composites to make any quantification of their numbers impossible, so this mixed data does not exist from Figure 4b.The nucleation activity of the PC phase of PP is small. The nucleation of any PC in PP can be attributed to impurities that affect the more complex nature of the PA from the PC phase. It is able to crystallize at higher temperatures than PP, fractional crystallization may occur and the T temperature is shifted to much lower values (see References [29-39]. However, as DSC experiments show that in the current case The phase of the PA is capable of crystallizing (fashion before fractionation) the PP matrix, and the nucleation of PP may have epitaxy origin.The material shown in the figure represents a PLOAM micrograph. Pure PP has typical α-phase negative spherulites (Fig. 5A) in the case of PP-PA blends (Fig. 5B), and the PA phase is dispersed with droplets of size greater than one micron (see SEM micrograph, Fig. 1) . We could not observe the spherulites of the B-phase type in PP-PA blends. Even according to WAXD, 20% of them can be formed in injection moldedspecimens. It must be borne in mind that the samples taken using the PLOAM test were cut off from the injection molded specimens but their thermal history (direction) was removed by melting prior to melting for isothermal crystallization nucleation experiments.The PA droplets are markedly enhanced by the nucleation of polypropylene and the number of spherulites is greatly increased (see Figures 4 and 5). Simultaneously with the PP-PA blend of silica nanoparticles, the sharp increase in nucleation density and Fig. 5C indicate that the size of the spherulites is very small and difficult to identify.The PP-PC blends showed signs of sample formation during the PC phase, which was judged by large, irregularly shaped graphs. Significant effects: (a) No coalesced PC phase, now occurring finely dispersed small droplets and (B) increased nucleation density. As shown in the figure above, nano-SiO 2 tends to accumulate at the interface between the two components and prevent coalescence while promoting small disperse phase sizes.From the nucleation point of view, it is interesting to note that it is combined with nanosilica and as a better nucleating agent for PP. Combining PCs with nanosilica does not produce the same increase in nucleation density.Independent experiments (not shown here) PP _ SiO 2 samplesindicate that the number of active cores at 135 °C is almost the same as that of PP-PC-SiO2 intermixing. Therefore, silica cannot be regarded as a PP nucleating agent. Therefore, the most likely explanation for the results obtained is that PA is the most important reason for all the materials used between polypropylene nucleating agents. The increase in nucleation activity to a large extent may be due to the fact that these nanoparticles reduce the size of the PA droplets and improve its dispersion in the PP matrix, improving the PP and PA in the interfacial blend system. Between the regions. DSC results show that nano-SiO 2 is added here without a nuclear PA phase.4 Conclusion5% weight of polypropylene/hydrophobic nanosilica blended polyamide and polypropylene/polycarbonate (80E20 wt/wt) blends form a powerful LED to reduce the size of dispersed droplets. This small fraction of reduced droplet size is due to the preferential migration of silica nanoparticles between the phases PP and PA and PC, resulting in an anti-aggregation and blocking the formation of droplets of the dispersed phase.The use of optical microscopy shows that the addition of PA, the influence of PC's PA-Sio 2 or PC-Sio 2 combination on nucleation, the nucleation density of PP polypropylene under isothermal conditions is in the following approximate order: PP <PP-PC <PP -PC-SiO 2<<PP-PA<<< PP-PA-SiO 2. PA Drip Nucleation PP Production of nucleation densities at isothermal temperatures is higher than with PC or PC Sio 2D. When nanosilica is also added to the PP-PA blend, the dispersion-enhanced mixing of the enhanced nanocomposites yields an intrinsic factor PP-PA-Sio2 blend that represents a PA that is identified as having a high nucleation rate, due to nanoseconds Silicon oxide did not produce any significant nucleation PP. PLOAM was found to be a more sensitive tool than traditional cooling DSC scans to determine differences in nucleation behavior. The isothermal DSC crystallization kinetics measurements also revealed how the differences in nucleation kinetics were compared to the growth kinetic measurements.Blends (and nanocomposites of immiscible blends) and matrix PP spherulite assemblies can grow and their growth kinetics are independent. The presence of a secondary phase of density causes differences in the (PA or PC) and nanosilica nuclei. On the other hand, the overall isothermal crystallization kinetics, including nucleation and growth, strongly influence the nucleation kinetics by PLOAM. Both the spherulite growth kinetics and the overall crystallization kinetics were successfully modeled by Laurie and Huffman theory.Although various similarities in the morphological structure of these two filled and unfilled blends were observed, their mechanical properties are different, and the reason for this effect is currently being investigated.The addition of 5% by weight of hydrophobic nano-SiO 2 resulted in breaking the strain-enhancement of the PP-PC blend and further weakening the PP-PA blend.中文译文纳米二氧化硅对PP-PC和PP-PA共混物的成核，结晶和热塑性能的影响Laoutid F, Estrada E, Michell R M, et al摘要80(wt%)聚丙烯与20(wt %)聚酰胺和聚碳酸酯有或没有添加5%纳米二氧化硅通过熔融混合制备不混溶的共聚物。
富马酸非索罗定合成工艺流程The synthesis process of fumaric acid maleic anhydride involves several key steps. First, maleic anhydride is reacted with water to form maleic acid, which is then further reacted with alcohol to produce dimethyl maleate. Next, the dimethyl maleate is hydrogenated to yield dimethyl succinate, followed by hydrolysis to obtain dimethyl fumarate. Finally, the dimethyl fumarate is esterified with methanol to yield fumaric acid. This complex and delicate process requires precise control and careful monitoring to ensure high yield and purity.对于富马酸非索罗定的合成过程，需要严格控制每一个步骤，确保反应条件的准确性和稳定性。
从雄性无水酸到二甲酯和食品级富马酸之间的复杂转化涉及多个中间体的合成和反应，而每一个环节都需要精密的操作和严密的监控。
细致入微的实验设计和仔细的工艺控制是保证产物纯度和产率的关键因素。
这一合成工艺流程需要工作者具备丰富的化学知识和实践经验，同时具备严密的实验态度和耐心。
In addition to technical expertise, safety precautions must also be strictly adhered to throughout the synthesis process. Many of thechemicals involved in the production of fumaric acid maleic anhydride are hazardous and may pose risks to both human health and the environment. Proper ventilation, personal protective equipment, and emergency response protocols must be in place to mitigate these risks. Furthermore, regular inspections and maintenance of equipment are essential to prevent accidents and ensure a safe working environment for all personnel involved in the production process.在富马酸非索罗定的合成过程中，安全防范措施至关重要，不能忽视。
第36卷 增刊(2)1997年 12月中山大学学报(自然科学版)ACT A SCIEN T I AR U M N A T U R AL IU MU N IV ERSIT AT IS SU N Y AT SENIVo l.36 Suppl.(2)Dec. 1997 马来酸酐自由基聚合廖爱德 徐文烈 钟建权(中山大学化学与化学工程学院,广州510275)摘 要 考察了以BP O和BPP D为引发剂的马来酸酐聚合影响因素.结果表明,用二甲苯、丙酮与DM F混合溶剂作为反应介质,聚合产率较高,可达68%～90%,BP O的引发效果优于BP-PD,聚合产率随反应温度升高而增加,但存在最适宜的反应温度(125℃),超过此温度产率反而下降.关键词 马来酸酐,自由基聚合分类号 O631马来酸酐因其分子结构中同时存在双键和酸酐基,赋予它独特的性质,使其能进行加聚和缩聚反应,而一直倍受人们注意.但因其空间位阻及极性影响等因素,长期以来普遍认为难以进行均聚.直到1961年才有报导用辐射引发获得聚马来酸酐[1],但转化率很低.以后的10年间,许多学者在马来酸酐的均聚中做了不少工作,但都没有取得突破性进展,往往是引发剂用量大或聚合产率低,从而导致聚马来酸酐生产成本高,限制其应用.我国聚马来酸酐的生产始于70年代末期,但有关研究报导却很少.聚马来酸酐用于阻垢剂、扩散剂、金属表面处理剂,以及纤维和塑料的抗静电剂等多个应用领域,均显示出优越的性能[2].本文从溶剂、引发剂、聚合温度等多方面探索了马来酸酐溶液聚合的规律,并对产物进行了表征.1 实验部分1.1 原料和试剂马来酸酐:纯度≥99.5%;溶剂,均为CP级,使用前经干燥处理;过氧化二苯甲酰(BPO),过氧化二碳酸双(2-苯基乙氧基)酯(BPPD),使用前经纯化处理.1.2 聚合反应在带有搅拌器、回流装置、温度计的3口瓶中进行反应.聚合前仪器先经高温干燥.反应结束后,加入沉淀剂,反复萃取以除去未反应的单体.1.3 分析测试NICOLET Analy tical Instruments5DX红外光谱仪;美国Water209H PLC仪; Rirkin-Elmer公司DT A1700DSC仪.收稿日期:1997-04-23 廖爱德,女,60岁,高级工程师2 结果与讨论2.1 溶剂对聚合反应的影响丙酮、DM F 、DM SO 均可溶解单体和聚合物,反应在均相中进行;苯、甲苯、二甲苯和卤代苯可溶解单体,但不能溶解聚合物,反应在异相中进行.从表1可见,聚合产率与溶剂性质没有明显的变化规律,其中以丙酮、DMF 、DM SO 、二甲苯作溶剂得到聚合产率较高,特别是DM F,产率可达74%.表1 溶剂对聚合反应的影响溶剂 1)反应温度/℃产率/%溶剂 反应温度/℃产率/%丙酮20.70561)59.4苯 2.28802)28.3DM F 36.719573.8甲苯 2.249546.2DM SO 48.99553.3o -二甲苯 2.266氯苯 5.659515.1m -二甲苯2.3749568.5溴苯3.089511.8p -二甲苯2.270 聚合条件:c (M )=4.5mo l /L ;x (BPO )=6%;t =6h ;1) 的单位为L mo l -1 cm -1;2)该溶剂的回流温度图1是采用混合溶剂(丙酮和DMF )的结果. (丙酮)=70%时聚合产率高达90%以上,比单独使用DM F 或丙酮都要高,且产物颜色较浅.图1 溶剂混合比对聚合反应的影响聚合条件:c (M )=4.5m ol /L ;x (BPO )=6%; =57℃;t =6h图2 温度对聚合反应的影响c (M )=4.5mol /L ;x (BPO )=6%;t =6h;溶剂为二甲苯2.2 温度对聚合反应的影响图2可见用BPO 作引发剂时反应温度对聚合物产率的影响明显;而用BPP D 则影响不大.BP O 分解活化能(E d )较BPP D 大,由A rr benius 公式可知,E d 较大时温度对k d 的影响也大,而k d 直接影响到聚合反应的速率和聚合产率.从图2还可见.无论用何种引发剂,反应温度超过125℃后,聚合产率都开始下降.K ellou [3]计算了马来酸酐聚合的最高温度约为150℃,与上述实验结果相符.2.3 引发剂用量对聚合反应的影响 图3(a)可见,在不同反应溶剂中,聚合产率随引发剂用量增加而增加的速率是不同的.在相同引发77增刊(2) 廖爱德等:马来酸酐自由基聚合图3 不同溶剂(a),和不同引发剂体系(b)中引发剂用量对聚合反应的影响c (M )=4.5mo l/L ;t =6h;(b) =95℃剂用量下,用混合溶剂可获得最大的产率;用丙酮作溶剂即使引发剂用量较大,也难以使单体转化完全.图3(b )中,聚合产率随BP O 用量增加而增加;当BP PD 用量增加时,聚合产率增加到一定程度后反而下降.3 聚合物表征图4(a )聚合物红外光谱图中,在1780～1850,1240cm -1处分别出现聚马来酸酐的C =O ,C -O 的特征吸收峰.GP C 分析表明实验所得聚马来酸酐的数均相对分子质量为300～800,即为马来酸酐的齐聚物.在聚合物的D SC 谱图(图4(b))上出现2个结晶熔融峰(144.2℃和171.5℃),这可能是由于产物中不同分子质量的马来酸酐齐聚物的熔点不同所致.图4 聚合产物的红外光谱(a)和D SC 谱(b)c (M )=4.5mol/L ;t =6h; =95℃;x (BP O )=6%;溶剂为二甲苯78中山大学学报(自然科学版) 第36卷参考文献1 T rivedl B C ,Culberfr on B M .M aleic anhy dr ide .N ew Y o rk .19822 朱清泉,郑邦乾.用作防垢剂的顺丁烯二酐共聚物的合成.工业水处理,1985,5(1):16～213 K ello u M S,Jenner G.Homo po ly mer izatio n r edicalaire.Eur Polym J,1976(12):883Radical Polymerization of Maleic AnhydrideL iao A ide X u W enlie Zhong J ianquanAbstract The influence facto rs for the r edical polym erization of maleic anhydride w er e in-vestigated.T he results show ed that the poly merization y ied w as hig h (68%～90%)w ith x ylene and m ix ed soluent of aceto ne and DM F as reactio n m idium.T he initiating effecience of BPO w as higher than that o f BPPD.Polym er ization y ied increased with the increase of tem perature ,but decreased w hen the temper ature w as over 125℃.Keywords m aleic anhy dride,radical po lymerization79增刊(2) 廖爱德等:马来酸酐自由基聚合Schoo l o f Chem istry and Chemical Engineer ing ,Z ho ngshan U niver sity ,Guangzhou 510275。
Influence of Maleic Anhydride on the Compatibility of Thermal Plasticized Starch and Linear Low-Density PolyethyleneShujun Wang,Jiugao Yu,Jinglin YuSchool of Science,Tianjn University,Tianjin300072,ChinaReceived25August2003;accepted1December2003DOI10.1002/app.20416Published online in Wiley InterScience().ABSTRACT:In the presence of dicumyl peroxide,the compatibility of thermal plasticized starch/linear low-den-sity polyethylene(TPS/LLDPE)blends using maleic anhy-dride(MAH)as compatibilizer was investigated.The ther-mal plasticization of starch and its compatibilizing modifi-cation with LLDPE was accomplished in a single-screw extruder at the same time.We prepared three types of blends containing different percentages of TPS and MAH. The content of MAH based on LLDPE was0,1,and2wt%, respectively.The morphology of the blends was studied by SEM.It was found that,with the addition of MAH,the blends have good interfacial adhesion andfinely dispersed TPS and LLDPE phases,which is reflected in the mechanical and thermal properties of the blends.The blends containing MAH showed higher tensile strength,elongation at break, and thermal stability than those of blends without MAH. The rheologic properties of the blends demonstrated the existence of processing.Finally,the dynamic thermal me-chanical analysis results indicated that,with the addition of MAH,the compatibility between TPS and LLDPE in the blends was substantially improved.©2004Wiley Periodicals, Inc.J Appl Polym Sci93:686–695,2004Key words:starch;polyethylene(PE);blends;compatibility; rheologyINTRODUCTIONOver the last50years,synthetic polymers have be-come the major new materials replacing the traditional ones such as paper,glass,steel,and aluminum in many applications.1These new synthetic polymers have many advantages,such as high tensile strength and elongation at break,and are easily produced into various end products with desirable properties.The polymers also have some disadvantages,however, mainly the nonbiodegradability that causes many en-vironmental problems.Various approaches to render synthetic polymers degradable have been considered. The earliest method was the addition of native starch granules to low-density polyethylene(LDPE),which was found in Griffin’s patents.2–4However,these ma-terials had poor tensile strength,elongation at break, and biodegradability.As a result of these efforts,sev-eral commercial products have been developed over the last few years,but most of them contain relatively low amounts of starch because increasing the amount of starch would induce a decrease in both tensile strength and elongation at break.5This deterioration arises from the different polar characteristics of starch and most of the synthetic polymers,which lead to poor interfacial adhesion.To increase the interfacial adhesion and further improve the mechanical proper-ties,a compatibilizer must be used.The ethylene–acrylic acid(EAA)copolymer is the most effective compatibilizer used so far,but it must be used in large amounts to achieve satisfactory me-chanical properties.Otey et al.6,7produced blown films containing up to40–50wt%gelatinized starch along with EAA and ammonia.The carboxylic groups of EAA can form V-type complexes with the hydroxyl groups of starch,8,9increasing the tolerated amounts of starch in the blends,in which case it could lower the biodegradation rate of starch.10On the other hand, EAA has an accelerating effort on thermooxidative degradation of LDPE/starch blends when used in low amounts,together with a prooxidant.11Complexes similar to EAA can also be formed with hydroxyl groups of the polyethylene–vinyl alcohol (EVOH)copolymer.12As a result,materials with high amounts of starch can be produced.Also,the addition of EVOH can increase the processing ability and in-jection moldability of plasticized starch.13Poly(vinyl alcohol),however,is water soluble,thus limiting the use of such materials in aquatic environments.In the last few years,increased interest has devel-oped with respect to starch together with polymers containing reactive groups,such as copolymers of sty-rene–maleic anhydride(SMA),ethylene–propylene–Correspondence to:J.Yu(edwinwa@). Journal of Applied Polymer Science,Vol.93,686–695(2004)©2004Wiley Periodicals,Inc.maleic anhydride(EPMA),propylene–glycicyl methacrylate(PGMA),and ethylene–maleic anhy-dride(EMA),14–17although these copolymers are ex-pensive and difficult to produce.In the present study, wefirst used MAH as the compatibilizer in a thermal plasticized starch/linear low-density polyethylene (TPS/LLDPE)system,in the presence of dicumyl per-oxide.The main objective was to test the compatibility of these blends.EXPERIMENTALMaterialsThe linear low-density polyethylene(LLDPE7042) was purchased from Jilin Petrochemical Filiale(Jilin, China).The native corn starch(ST,11%moisture), containing30wt%amylose and70wt%amylopectin, was obtained from Langfang Starch Co.(Langfang,Hebei,China).The plasticizer,glycerol,was pur-chased from Tianjin Chemical Reagent Factory(Tian-jin,China).Maleic anhydride(MAH),purchased from Tianjin Chemical Reagent Factory,was recrystallized twice with CHCl3before use.Dicumyl peroxide (DCP),obtained from Shanghai Chemical Reagent Co.,China Pharmacy Group(Shanghai,China),was recrystallized with absolute alcohol before use. Sample preparationBlending was carried out by use of a high-speed mixer GH-100Y(made in China)at room temperature.The rotor rate was maintained at3000rpm for2min, adding LLDPE and starchfirst,then adding glycerol, MAH,and DCP.The mixtures were manually fed into a laboratory-scale single-screw extruder[SJ-25(S), screw diameter(d)ϭ30mm;length-to-diameter (L/D)ratioϭ25:1;made in China].The extrusion conditions were as follows:the temperature profile along the extruder barrel:140–145–150–130°C(from feed zone to die);the screw speed was15rpm.The die was a round sheet with3-mm-diameter holes.For TPS/LLDPE blends,five different levels of TPS were used:50,60,70,80,and90wt%.MAH and DCP were used as monomer and initiator at1and0.1wt%levels based on LLDPE,respectively.Some extrudates were hot pressed into thinfilms at110–120°C and10kN for 15min,for dynamic mechanical analysis.The level of glycerol in the blends was30wt%based on the native corn starch.The detailed compositions of samples are listed in Table I.Scanning electron microscopy(SEM)Specimens were fractured after being frozen in liquid nitrogen and the exposed surfaces were observed with an environmental electron microscope(ESEM,Philips XL-3,The Netherlands).All surfaces were coated withgold to avoid charging under the election beam.Theelectron gun voltage was set at30kV.The micro-graphs of samples were taken at magnifications of ϫ500to identify cracks,holes,and other changes on the surface of the samples in either the presence or theabsence of MAH.Mechanical properties of blendsMeasurements of the mechanical properties,such astensile strength and elongation at break,were per-formed according to the method detailed in ASTMD828-88(ASTM1989)on a WD-5electron tester.Mea-surements were done using a100mm/min crossheadspeed.Before the measurement,the samples were con-ditioned at50Ϯ5%relative humidity for48h at anambient temperature in a closed chamber containing a33.46wt%CaCl2solution in a beaker.Ten measure-ments were conducted for each sample and the resultswere averaged to obtain a mean value.The measure-ments are reported as the relative mechanical property(i.e.,ratio of a mechanical property of the blend to thatof neat LLDPE)in all cases.Thermogravimetric analysis(TGA)The thermal properties of the blends were measuredwith a ZTY-ZP type thermal analyzer.The sampleweight varied from10to15mg.Samples were heatedfrom ambient temperature to500°C at a heating rate of15°C/min.Derivatives of TGA thermograms were ob-tained using Origin6.0analysis software(RockWareInc.,Golden,CO).RheologyThe extruded strips were cut into small pieces,whichwere tested by an XYL-II capillary rheometer.TheTABLE ISamples Codes and Composition of Raw MaterialsSamplecodeRaw materialsLLDPE ST GL MAH DCP 15038.511.5——24046.213.8——33053.816.2——42061.518.5——51069.220.8——65038.0811.370.50.05 74045.8113.750.40.04 83053.5916.080.30.03 92061.3718.410.20.02 101069.1520.740.10.01 115037.6511.30 1.00.05 124045.5113.650.80.04 133053.3616.010.60.03 142061.2218.360.40.02 151069.0720.720.20.01EFFECT OF MAH ON TPS/LLDPE COMPATIBILITY687capillary radius was1mm and L/D was40.The small pieces were placed into the barrel through a funnel and then packed down with the plunger until thefirst extrudate appeared at the capillary exit.The samples were allowed to come to temperature(balancing for 10–15min),and were then forced through the capil-lary by the plunger at preselected velocities.The next velocity in the measure schedule began when the load versus extension curves reached a slope close to zero. The load on the plunger and plunger speed provided the total pressure drop through the barrel and capil-lary and the volumeflow rate.Shear rate(␥)and shear stress()were calculated by standard methods.To understand the processing properties of TPS/LLDPE blends,the rheology experiments were conducted at 125°C,which covered the processing temperature range.Dynamic mechanical thermal analysis(DTMA) DTMA,using a Mark Netzsch DMA242analyzer (Netzsch-Gera¨tebau GmbH,Bavaria,Germany),was used on hot-pressed thick specimens(ϳ2.0ϫ11ϫ16 mm),in a single-cantilever bending mode at a fre-quency of3.33Hz and a strainϫ2N,corresponding to a maximum displacement amplitude of30m.The analyzer compared the stress and strain signals and resolved the strain into the in-phase(storage)and out-of-phase(loss)components,from which storage or elastic(EЈ)and loss(EЉ)moduli,as well as the tan␦(ϭEЉ/EЈ),were obtained as a function of temperature. The range of temperature was fromϪ100to100°C,at a standard heating rate of3.0°C/min.Samples were coated with silicone wax to prevent water from evap-orating during heating.For polymeric materials a de-crease in storage modulus and a peak in tan␦are used as indicators of glass transition.RESULTS AND DISCUSSIONBlend morphologyIn polymer blends,it is necessary to study the mor-phology of thefinal product because most of its prop-erties,especially its mechanical properties,depend on it.In most cases,the major components of the blends form the continuous phase,whereas the minor com-ponents constitute the dispersed phase.However,as the volume fraction of the minor components in-creases to a certain volume,the process will transfer from the dispersed phase to the continuous phase.18 Thus,in our present study,for a blend with high starch content,starch is expected to be the continuous phase and LLDPE is the dispersed phase.Another parameter affecting the morphology and properties of polymeric blends is the use of compati-bilizer.Preliminary studies showed that afiner and more uniform dispersion of starch in the LDPE matrix could be achieved in the blends compatibilized with PE-g-MAH copolymers.19To see the interfacial struc-ture between the matrix and the dispersed phase,SEM micrographs of fracture surfaces were obtained and are shown in Figure1.Figure1(a),(b),and(bЈ)are SEM micrographs of samples1,6,and11,respectively.As can be seen from Figure1(a),many starch particles were obviously not disrupted and some of them were removed from the surface of the sample during the fracture of the spec-imen,leaving some cavities in the fracture surface, presumably because of the weak interfacial adhesion between TPS and LLDPE.Because most of the starch particles still remained on the fracture surface,the starch phase appeared to be practically separated from the LLDPE.Besides,the average size of starch parti-cles was about10m,whereas the native corn starch particle was about15m in diameter.In Figure1(b) and(bЈ),we can scarcely see the separated starch particles,and there was no apparent phase interface between TPS and LLDPE;the average size of the starch particles was about5m.Moreover,the frac-ture surface did not have cavities because the starch particles were not removed from the fracture surface during the preparation of SEM samples.These facts indicated that the interfacial adhesion of the blends with addition of MAH is improved.Blends containing up to60,70,80,and90wt%TPS exhibited the same phenomenon,that is to say,the blends with the addition of MAH have better micro-scopic morphology than that of blends without the addition of MAH.Mechanical propertiesFigures2and3show the effect of TPS content on the relative tensile strength and relative elongation at break of samples,respectively.The variation in the relative tensile strength and relative elongation at break of samples with MAH content is also shown in thefigures.As observed from Figures2and3,the relative ten-sile strength and the relative elongation at break were decreased with increasing TPS content for all samples, regardless of the existence of MAH.This general phe-nomenon was because of the presence of starch parti-cles,which do not contribute to the mechanical prop-erties of the blends,and has been observed in many studies.20–22However,the main purpose was to test the effect of MAH on the mechanical properties of TPS/LLDPE blends.As is well known,the starch granule is highly hy-drophilic,containing hydroyl groups on its surface, whereas LLDPE is basically nonpolar.Therefore,the formation of the strong interfacial bonds such as hy-drogen bonds is not feasible.As a result,when stress688WANG,YU,AND YUFigure 1SEM micrographs of the surface of samples:(a)sample 1;(b)sample 6;(b Ј)sample 11;(c)sample 3;(d)sample 8;(e)sample 5;(f)sample 10.EFFECT OF MAH ON TPS/LLDPE COMPATIBILITY 689was exerted on the blends,the fracture resistance of the blends without the addition of MAH was not improved.However,the relative tensile strength and the relative elongation at break of the samples were improved with the addition of MAH.The addition of MAH substantially strengthened TPS and LLDPE in-terfacial adhesion;this increased interfacial adhesion for the blends was believed to be attributed to the chemical reaction of MAH groups with hydroxyl groups on starch at the interface.However,further increases in the MAH content reduced the relative tensile strength and the relative elongation at break.Nonetheless,on the other hand,the compatibility was improved with increasing MAH content.The increas-ing content of MAH would critically suppress TPS and LLDPE,and the mechanical properties of the final product would be impaired.Factorial analysis of the experimental data was per-formed and nonlinear regression equations for the relative tensile strength (RTS)and the relative elonga-tion at break (REB)were obtained,as follows:RTS ϭ1.61719Ϫ0.02497͑TPS ͒ϩ0.53002͑C ͒ϩ0.00012͑TPS ͒2Ϫ0.35066͑C ͒2Ϫ0.00269͑TPS)(C ͒r ϭ0.99(1)REB ϭ0.59695Ϫ0.01548͑TPS ͒ϩ0.74235͑C ͒ϩ0.00011͑TPS ͒2Ϫ0.18747͑C ͒2Ϫ0.00829͑TPS)(C ͒r ϭ0.92(2)In the two equations,TPS and C refer to the contents of TPS and MAH in the blends,respectively.Figure 2Relative tensile stress ofsamples.Figure 3Relative elongation at break of samples.690WANG,YU,AND YUAs can be seen from Figures 2and 3,the improve-ment in the mechanical properties of blends was not significant for two reasons:(1)in the blends without the addition of MAH,the rigid starch particles were slightly disrupted,although with the addition of MAH,the rigid starch particles were destroyed com-pletely,and the rigid starch particles could resist higher stress than the plasticized starch particles;(2)it was not clear at this moment how the MAH groups were exactly distributed in the blends.Even though some of the MAH groups appeared to be situated at the interface between TPS and LLDPE phases,thus enhancing the interfacial adhesion,some might be included in the LLDPE phase.If some fractions of MAH groups formed micellar domains in the LLDPE phase,those would not contribute to the improvement of the interfacial adhesion strength.Furthermore,sucha micellar structure might diminish the mechanical properties of the blends.TGAFigures 4and 5show TG thermograms of samples 3,8,and 13,and samples 6,7,8,9,10,respectively.As obtained from Figures 4and 5,three well-de-fined shifts were observed in the TG curves.The first shift,at around 100°C,was produced by water evap-oration or the unreacted MAH sublimation;the sec-ond shift started at 180°C and was attributed to the evaporation of glycerol.This process continued grad-ually up to 300°C,where the thermal degradation of starch occurred;the last shift,at around 400°C,was caused by the thermal decomposition ofLLDPE.Figure 4TG thermogram ofsamples.Figure 5TG thermogram of samples.EFFECT OF MAH ON TPS/LLDPE COMPATIBILITY 691At around 400°C,the total weight loss of sample 3was 68wt %.The data were in agreement with the TPS content.However,the data were 58and 48wt %,corresponding to samples 13and 8,respectively.Be-fore 400°C,the weight loss of samples was mainly caused by the thermal degradation of TPS.According to the content of TPS of samples,the reduction in weight loss was the result of the improvement in the thermal stability.The other samples,with equal load-ing of TPS,followed a similar trend.Table II shows the weight loss of other samples at 400°C.The improve-ment in thermal stability also confirmed that,with the addition of MAH,the adhesion between TPS and LL-DPE in the blends was enhanced,further improving the compatibility of TPS and LLDPE.However,with increasing MAH content,the thermal stability of sam-ples decreased,perhaps attributable to the deteriora-tion of DCP and MAH on TPS and LLDPE during extrusion.From Figure 5,we can see that with increas-ing LLDPE content,the thermal stability of samples was enhanced.RheologyThe data for the shear stress and the apparent viscos-ity as a function of shear rate are shown in Figures 6and 7,respectively.As observed from Figures 6and 7,with increasing shear rate,the apparent viscosity of the three sam-ples evidenced a declining trend,and such flow behavior was designated shear thinning.The sam-ples exhibited power-law behavior,which was as-cribed to the gradual deterioration of intermolecular action between starch and LLDPE.The apparent viscosity of samples 6and 11was lower than that of sample 1at the same shear rate,which was closely related to the molecular realignment.In sample 1,TPS and LLDPE were not well dispersed (shown in SEM micrographs),and the adhesion between TPS and LLDPE was poor.The rigid starch particles and the molecular orientation prevented the blend melt from flowing smoothly at the experimental temper-ature,so apparent viscosity is high.In samples 6and 11,however,the arrangement of molecules was more orderly than that of sample 1because of the good plasticization of starch and good compatibility between TPS and LLDPE.So the action of rigid starch particles and the molecular orientation were decreased under the shear stress.Consequently,the blend melt reduced the flow fiction obstruction and produced the lower apparent viscosity.The viscos-ity of sample 6was higher than that of sample 11as a result of the substantial destruction of MAH acting on the TPS and LLDPE.TABLE IITG Percentage of SamplesSample TPS content (%)25°C Weight loss (%)400°C Error (%)15049.221149.4539.721.1648.9532.534.626058.4 3.331259.5649.317.7759.1540.232.448078.1 2.51479.7868.514.8979.5849.438.459091.7 1.111589.8981.69.891089.7972.819.81Figure 6w ϳ␥w curves of samples at 125°C.692WANG,YU,AND YUDTMAThe dynamic thermal mechanical data for the blends,that is,the storage moduli (E Ј)and the loss factor (tan ␦)as a function of temperature,are shown in Figures 8and 9,respectively.Storage modulus is an important parameter of the rigidity of materials.As can be seen from Figure 8,the storage moduli of samples 6and 8were lower than those of samples 1and 3,which was related to the plasticization of starch.The plasticization of starch in samples 6and 8was better than that in samples 1and 3(which can be seen in SEM micrographs).Some particles,called agglomerates,were always in contact with each other.Rigid agglomerates of samples 1and 3,in which there was no motion at particle–particle contact points,increased the modulus more than that found in samples 6and 8,in which TPS and LLDPE were perfectly dispersed and there were only a few rigid starch particles.As reported in the literature,23,24the glass-transition temperature (T g )of LLDPE is around Ϫ80to Ϫ120°C;that of the plasticized starch with glycerol is 40–60°C.As can be seen from Figure 9,the four samples all exhibited two glass-transition temperatures,all be-tween that of pure TPS and that of LLDPE,corre-sponding to LLDPE (Ͻ0°C)and TPS (Ͼ0°C).Thus TPS and LLDPE in the samples were not compatibilized at the molecular level.However,by comparing the blends with MAH and those without MAH,we found that the glass-transition temperatures of TPS and LL-DPE in samples 6and 8were closer than they were in samples 1and 3.Although the compatibility at the molecular level was impossible,the interaction power between TPS and LLDPE in the sample wasimprovedFigure 7a ϳ␥w curves of samples at125°C.Figure 8DMA thermogram of samples:storage modulus.EFFECT OF MAH ON TPS/LLDPE COMPATIBILITY 693with the addition of MAH,thus increasing the com-patibility of TPS and LLDPE.We did not obtain a continuously uniform system,although the improve-ment in compatibility promoted good mechanical properties and thermal stability in the blends.Mechanism of compatibilityReasons for incompatibility of TPS/LLDPE blends are high interfacial tension and,consequently,poor inter-facial adhesion between the two components.How-ever,the phenomenon of compatibility can be induced in an immiscible binary system by introducing a third component that either will interact chemically with both phases or will have specific interaction with one phase and physical interaction with the other.The addition of a block or graft copolymer reduces the interfacial tension between the two phases,increases the surface area of the dispersed phase,promotes adhesion between the phase components,and stabi-lizes the dispersed phase morphology.25Investigation of PE-g -MAH,used as compatibilizer between starch and PE,was reported in a number of studies in the literature.18,26–28A uniform viewpoint that PE-g -MAH was used as compatibilizer is based on two factors:(1)the ester-forming ability of anhy-dride groups with hydroxyl groups on starch,the hydrogen bond–forming ability between carboxyl groups of hydrolyzed MAH and hydroxyl groups on starch;(2)the substantial compatibility between grafted PE chain and PE phase.The mechanism is illustrated as follows.On the basis of this concept,we designed an exper-iment that,at the same extruded conditions,LLDPE and MAH were simultaneously extruded in the pres-ence of DCP,and the extrudate was purified to re-move the unreacted MAH and small molecules,The purified method was as follows:dissolution of modi-fied LLDPE in xylene followed by precipitation in acetone.29FTIR spectra of the grafted product and pure LLDPE are shown in Figure 11.By comparing the pure LLDPE with the grafted product,weobservedFigure 9DMA thermogram of samples:tan ␦.Figure 10Interficial chemical reaction of MAH and OH.694WANG,YU,AND YUthe symmetrical and asymmetrical stretching vibra-tion bonds of anhydride groups at 1869and 1791cm Ϫ1,respectively.This verified the fact that MAH grafted onto LLDPE in the presence of DCP,and was used as a compatibilizer in the TPS/LLDPE blends during the extrusion.CONCLUSIONSIn the presence of DCP,TPS and LLDPE were com-patibilized with the addition of MAH.The blends with the addition of MAH have higher tensile strength,elongation at break,and thermal stability than those of the blends without the addition of MAH.With in-creasing MAH content,the mechanical and thermal properties of the blends decreased,which is probably attributable to the deterioration of MAH to the starch particle and LLDPE in the presence of DCP during the extrusion.Another important finding is that the blends with the addition of MAH have better flow behavior,which arises from two factors:(1)the good arrangement of TPS and LLDPE;(2)the deterioration of MAH to the starch particle and LLDPE,thus caus-ing the molecular weight of TPS and LLDPE to de-crease.All of the above phenomena are ascribed to the improvement in the compatibility between TPS and LLDPE.References1.Guillet,J.In:Degradable Polymers:Principles and Applications,1st ed.;Scott,G.;Gilead,D.,Eds.;Chapman &Hall:London,1995;pp.216–246.2.Griffin,G.J.L.U.S.Pat.4,016,177,1977.3.Griffin,G.J.L.U.S.Pat.4,021,388,1977.4.Griffin,G.J.L.U.S.Pat.4,125,495,1978.5.Evangelista,R.L.;Nikolov,Z.L.;Sung,W.;Jane,J.L.;Gelina,R.L.Ind Eng Chem Res 1991,30,1841.6.Otey,F.H.;Westhoff,R.P.;Doane,W.M.Ind Eng Chem Prod Res Dev 1980,19,592.7.Otey,F.H.;Westhoff,R.P.;Doane,W.M.Ind Eng Chem Prod Res 1987,26,1659.8.Fanta,G.F.;Swanson,C.L.;Doane,W.M.J Appl Polym Sci 1990,40,811.9.Shogren,R.L.;Green,R.V.;Wu,Y.V.J Appl Polym Sci 1991,42,1701.10.Imam,S.H.;Gould,S.M.;Kinney,M.P.;Ramsay,A.M.;Tosyeson,T.R.Curr Microbiol 1992,25,1.11.Bikiaris,D.;Prinos,J.;Panagiotou,C.Polym Degrad Stab 1997,56,1.12.Bikiaris,D.In:Degradable Polymers:Principles and Applica-tions,1st ed.;Scott,G.;Gilead,D.,Eds.;Chapman &Hall:London,1995;p.112.13.George,E.R.;Sullivan,T.M.;Park,E.H.Polym Eng Sci 1994,34,17.14.Nie,L.;Narayan,R.;Grulke,E.A.Polymer 1995,36,2227.15.Yang,Z.;Bhattacharya,M.;Vaidya,U.R.Polymer 1996,37,2137.16.Vaidya,U.R.;Bhattacharya,M.J Appl Polym Sci 1994,52,617.17.Matzions,P.;Bikiaris,D.;Kokkou,S.;Panagiotou,C.J ApplPolym Sci 2001,79,2584.18.Willemse,R.L.;Posthuma de Boer,A.;van Damand,J.;Gotsis,A.D.Polymer 1998,39,5879.19.Bikiaris,D.;Panagiotou,C.J Appl Polym Sci 1998,70,1503.20.Willett,J.L.J Appl Polym Sci 1994,54,1685.21.Nikolov,Z.L.;Evangeslista,R.L.;Wung,W.;Jane,J.L.;Gelina,R.J.Ind Eng Chem Res 1991,30,1841.22.Kang,B.G.;Yung,S.H.;Jie,J.E.;Yoon,B.S.;Soo,M.H.J ApplPolym Sci 1996,60,1977.23.Liang,Z.;Williams,H.L.J Appl Polym Sci 1992,44,699.24.Martin,O.;Averous,L.Polymer 2001,42,6209.25.Tedsco,A.;Barbosa,R.V.;Nachtigall,S.M.B.;Mauler,R.S.Polym Test 2002,21,11.26.Seong,I.Y.;Tae,Y.L.;Jin-san,Y.;Ik-mo,L.;Mal-nam,K.;Han,S.L.J Appl Polym Sci 2002,83,767.27.Bikiaris,D.;Prinos,J.;Koutsopoulos,K.;Vouroutzis,N.;Pav-lidou,E.;Frangis,N.;Panagiotou,C.Polym Degrad Stab 1998,59,287.28.Chandra,R.;Rustgi,R.Polym Degrad Stab 1997,56,185.29.Bettini,S.H.P.;Agnelli,J.A.M.Polym Test 2000,15,3.Figure 11FTIR spectra of PE and PE–g –MAH.(a)PE;(b)PE–g -MAH.EFFECT OF MAH ON TPS/LLDPE COMPATIBILITY 695。
