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2，5-二甲基对苯醌二亚胺与烷氧基苯共聚物的合成及性能表征孟新涛;利晓东;石伟;张建平;司马义·努尔拉【摘要】通过金属配合物催化法，在1，3-双（二苯基膦）丙烷二氯化镍（1I）存在的条件下，合成了2，5-二甲基对苯醌二亚胺与不同碳数的碘代烷氧基苯的3种共聚物。
通过FT—IR、^1H—NMR、UV—Vis、循环伏安（CV）、XRD和凝胶渗透色谱（GPC）等测试手段对其进行了表征。
结果表明：3种共聚物在三氟乙酸（TFA）溶液中的紫外可见最大吸收波长分别在517、576、651nm处；该类共聚物均在-0．2～0．8V出现两对氧化还原峰；共聚物的规整度较高，衍射峰的位置在19．6v～23．5°。
%Using nickel( Ⅱ ) complex as catalyst, three type of copolymers which consisting 2,5-dimethyl- N, N1-p-benzoquinonediimine and Grignard reagent of iodo-alkoxy benzene with different carbon atoms were synthesized by metal comp FT-IR, 1H-NMR, UV-Vis, cycl exes catalyzed polymerization. These copolymers were characterized by c vohammogram (CV), XRD and GPC. Results show that the maximum UV-Vis absorption of these polymers appear at 517, 576, 651 nm in CF3COOH, respectively. The copoly- mers have two redox peaks in the range from -0.2 V to 0.8 V. The figures of copolymers have well cry- stallized, and the diffraction peaks in the range of 19.6°-23.5°.【期刊名称】《功能高分子学报》【年(卷),期】2012(025)004【总页数】5页(P369-373)【关键词】2，5-二甲基对苯醌二亚胺;格氏试剂;碘代烷氧基苯;镍（Ⅱ）配合物催化法【作者】孟新涛;利晓东;石伟;张建平;司马义·努尔拉【作者单位】新疆大学化学化工学院,功能高分子材料重点实验室,乌鲁木齐830046;新疆大学化学化工学院,功能高分子材料重点实验室,乌鲁木齐830046;新疆大学化学化工学院,功能高分子材料重点实验室,乌鲁木齐830046;新疆大学化学化工学院,功能高分子材料重点实验室,乌鲁木齐830046;新疆大学化学化工学院,功能高分子材料重点实验室,乌鲁木齐830046【正文语种】中文【中图分类】O63聚苯胺具有良好的导电性、热稳定性和容易成膜等特点，同时，又是良好的电磁屏蔽材料和电极材料［1－4］。
・诺贝尔奖工作回顾・核磁共振成像＿２００３年诺贝尔生理学或医学奖介绍及研究进展洪远凯（北京大学医学部生物物理学系，北京１００１９１）现代物质理论的基本前提是物质由原子组成，原子由原子核和围绕其运动的核外电子组成，而原子核又是由质子和中子构成。
原子是极小的粒子，其半径以Ａ（１０一ｏｍ）表示。
如此之小的原子，以前是无法直接观察的。
不过，四年前，宾尼库克领导的美国橡树岭国家实验室电子最微镜研究小组的研究人员以仓，ｌｉｄ录的分辨率清楚地观察到了原子世界，其观察原子的图像分辨率已达到０．６Ａ。
利用他们研究出的电子显微镜能够分辨出硅晶体的单个哑铃形状的原子¨ｏ（图１）。
圈１硅晶体原子成像物质世界中的基本单位主要是由原子组成的各类分子。
这些分子都很小，属微观范畴。
不管是有机物还是无机物，其各类分子具有不同的结构和不同的性质。
人们可以通过各种技术方法研究它们。
原子的诸多性质吸引了包括物理学家在内的广大科学工作者的研究兴趣，其研究结果不仅推动和发展了物理科学领域，而且应用到包括生命科学在内的广泛领域。
其中，基于核磁共振（ｎｕｃｌｅａｒｍａｇｎｅｔｉｃｒｅｓｏｎａｎｃｅ，ＮＭＲ）而发展的核磁共振成像技术（ｍａｇ—ｎｅｔｉｃｒｅｓｏｎａｎｃｅｉｍａｇｉｎｇ，ＭＲＩ）就是一个范例。
目前，核磁共振成像技术１３趋成熟，应用范围日益广泛，已经成为一项常规的临床医学检测手段，广泛应用于脑和脊椎病变以及癌症的治疗和诊断等领域。
２００３年１０月６日，瑞典卡罗林斯卡研究院宣布，当年的诺贝尔生理学或医学奖授予美国科学家保罗・劳特布尔（ＰａｕｌＣ．Ｌａｕｔｅｒｂｕｒ）和英国科学家彼得・曼斯菲尔得（ＰｅｔｅｒＭａｎｓｆｉｅｌｄ）（图２），以表彰他们在ＭＲＩ领域的突破性成就。
在获息被授予诺贝尔奖时，劳特布尔曾幽默地说“我听到过各种猜测，但现实仍令我惊讶”。
曼斯菲尔德更坦率地说“我想每个科学家都希望有一天，他们可以被挑选出来获得这样一个荣誉。
热重法评估聚芳醚的活化能郑一泉;陈锐;岑茵;姜苏俊;黄钰香;孙东海;禹权;江翼;敬新柯【摘要】阐述了近期对于快速热氧老化的评价方法,采用热重点斜法和改进的Kinssinger方法计算改性聚芳醚的氧化活化能,同时展开低温常规长期热氧老化试验,比较快速评价方法间和常规热氧老化试验方法的差异,通过数据分析可以发现常规老化活化能与改良Kinssinger方法推导的活化能之间存在比较好的对应关系.【期刊名称】《合成材料老化与应用》【年(卷),期】2015(044)002【总页数】5页(P51-55)【关键词】热氧老化;热重法;聚苯醚【作者】郑一泉;陈锐;岑茵;姜苏俊;黄钰香;孙东海;禹权;江翼;敬新柯【作者单位】金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663;金发科技股份有限公司,改性塑料国家工程实验室,广东广州510663【正文语种】中文【中图分类】TQ02近三十年来，研究者一直致力于研究绝缘材料在长期服役条件下的使用寿命，并且建立了大量的模型。
这些研究者建立了一些本构方程、物理模型来描述绝缘材料的变化，以便预测材料在热应力、电应力等物理场的作用的变化[1]。
这些模型的建立都需要长期的使用过程进行检验，长期使用寿命需要耗费大量的人力和物力，研究者一直试图采用短期方法来评价材料的使用寿命，因此快速评价高分子材料的使用寿命是一个热点研究问题[2-5]。
杏仁牛奶巧克力的品质变化动力学模型及货架期预测朱扬玲【摘要】为研究杏仁牛奶巧克力的货架期预测方法,设定了15℃、25℃、20℃3各不同储藏温度,并对感官、水分、菌落总数、酸价进行了检测.本研究采用Arrheniu方程对品质变化速率常数和温度T进行线性拟合,得到的活化能Ea为16.94KJ/mol,预测获得的货架期(20℃)为589天,按照安全系数0.8计算,保质期为1 5个月.实验证明,Arrhenius一级动力学模型能较好地描述15～30℃储藏条件下的杏仁牛奶巧克力的品质变化,预测方程的拟合程度较高,决定系数R2为0.9942,预测结果参考价值较大.【期刊名称】《中国食品工业》【年(卷),期】2015(000)008【总页数】4页(P66-69)【作者】朱扬玲【作者单位】通标标准技术服务(上海)有限公司上海201506【正文语种】中文货架期（shelf life），又称货架寿命，或保质期等。
食品货架期一般受内部因素（包括微生物数量、酶促反应和生化反应等）、外部因素（包括温度、相对湿度、pH值、压力、辐射等）及包装材料等影响[1]。
一般情况下，食品保质期是根据食品品质变得难以接受的天数，乘以0.7-0.8的安全系数来计算的。
由于现代食品工业的发展，许多预包装食品的货架期可以超过1年。
因此，对食品行业来说，在一个较短的时间内确定产品的货架寿命是很有必要的。
随着交叉学科的相互渗透，各种动力学模型在食品货架期预测中应用越来越广泛，包括阿伦尼乌斯（Arrhenius）方程[2]、威布尔危险值分析方法（Weibull Hazard Analysis, WHA）[3,4]、WLF（Williams-Landel-Ferry）方程[5]、Z值模型法[6,7]等。
其中，动力学模型结合Arrhenius方程是最经典，也是应用最广泛的一种货架期预测方法。
2003年，Suh等[8]通过建立0级反应动力学模型，研究了温度对桑葚汁褪色的影响，并通过统计分析确定了4个不同pH值的样品，在80℃-100℃间的活化能。
桑椹花色苷在不同糖体系中的热降解动力学研究摘要:对不同糖体系中桑椹花色苷降解动力学进行了研究｡结果显示桑椹花色苷自身的热降解动力学符合一级反应动力学,并且可用Arrhenius方程表示,其反应活化能为56.11 kJ/mol;但是,在葡萄糖､果糖､蔗糖体系中,除70℃时的葡萄糖体系外,花色苷的降解均不符合一级反应动力学｡同时,各种糖对花色苷降解均有促进作用,作用能力依次为果糖>蔗糖>葡萄糖,且每种糖对花色苷降解均具有浓度和温度效应,花色苷降解随着糖浓度增加以及温度增加而加快｡关键词:桑椹;花色苷;糖;热降解动力学Thermal Degradation Kinetics of Anthocyanins Obtained from Mulberry Juice in Different Sugar Model SystemsAbstract: Thermal degradation kinetics of anthocyanins obtained from muiberry juice was studied at selected temperature. Results indicated that the thermal degradation of anthocyanins followed first-order reaction kinetics, and they could be expressed by Arrhenius equation. The Ea values of the anthocyanins degradation was 56.11 kJ/mol. However, in the sugar model systems except for the glucose systems at 70℃, the thermal degradation of anthocyanins did not follow the first-order reaction kinetics. The promoting effects of sugars on anthocyanins degradation were according to the following descending order: fructose> sucrose> glucose. Moreover, the stimulative effects of sugars on anthocyanins degradation increased with the increasing of sugar concentration and temperature.Key words: mulberry juice; anthocyanins; sugar; thermal degradation kinetics花色苷由于其诸多功能活性,如抗氧化､抗血栓､抗辐射､抗动脉粥样硬化､预防糖尿病等[1-5],越来越受到人们的关注｡作为富含花色苷的水果,桑椹的保健作用逐渐被人们所熟识,因此桑椹及其相关产品具有广阔的市场前景｡但是,富含花色苷的果蔬加工中会遇到由花色苷降解所导致的褐变及沉淀等问题,从而影响产品的感官品质及营养价值｡花色苷的低稳定性是果蔬加工中,尤其是热处理过程中的一个重要问题｡对生产厂家和消费者来说,防止花色苷的降解具有重要意义｡果蔬中的主要成分,如抗坏血酸､糖､酚等,在花色苷降解中起到了重要作用｡其中,糖不仅是果蔬中重要的组成成分之一,同时也是果蔬加工中重要的添加剂,因此研究不同糖类对花色苷稳定性的影响非常必要｡部分报道认为糖通过降低水活或增色作用[6-8],对花色苷起到稳定作用;然而糖的热降解产物如糠醛却能参与花色苷的降解[9,10]｡目前有关桑椹花色苷的研究[11,12],主要集中在提取分离以及pH值､温度､金属离子､氧化剂等因素对桑椹花色苷稳定性的影响上,糖类对桑椹花色苷降解的影响未见报道｡因此,本文通过研究含糖模拟体系中桑椹花色苷降解动力学,以及研究不同糖模拟体系下桑椹花色苷的降解情况,更有利于我们认识桑椹花色苷的降解机制,同时,对桑椹加工提供一些理论依据,对其他含有花色苷的果蔬的加工同样具有重要意义｡1材料与方法1.1材料1.1.1原料桑椹原汁,购于宁波市鄞州区下应村天宫庄园,密封置于-18℃下保存备用｡1.1.2试剂实验所用试剂氯化钾､盐酸､醋酸钠､柠檬酸､柠檬酸钠､葡萄糖､果糖､蔗糖等均为分析纯｡NKA-9大孔树脂购于天津南开大学化工厂｡1.1.3仪器设备UV-1700 SPC型紫外可见分光光度计(日本岛津公司),Laborota 4000 Efficient 旋转蒸发仪(德国Heidolph公司)｡1.2方法1.2.1桑椹花色苷的提取先将树脂预处理,用两倍体积的2 mol/L NaOH洗涤,用去离子水洗至中性后,再用两倍体积的2 mol/L HCl洗涤,最后用去离子水洗至中性｡澄清果汁用处理好的大孔树脂层析柱(30.0 cm×2.5 cm ID)分离｡收集洗脱液,旋转蒸发除去乙醇｡得到的浓缩液用乙酸乙酯萃取,花色苷溶于水相中,重复3次,合并水相,减压浓缩,即得到桑椹花色苷粗提液｡1.2.2含糖模拟体系的构建将花色苷粗提液用柠檬酸-柠檬酸钠缓冲液稀释,调节pH值到4.1(实验测得桑椹果汁pH值为4.1,因此模拟体系选择该pH值)｡将稀释样品液等分,分别加入不同浓度(5%､10%､15%)的蔗糖､果糖､葡萄糖,配制不同的模拟体系以进行热降解动力学研究｡1.2.3热处理根据果汁加工中的温度,样品选择在70､80､90℃温度条件下均匀加热,每隔0.5 h取样检测｡具体方法如下,样品每10 mL分装在密封的玻璃管中,在设定的温度下恒温水浴｡在水浴时要注意不断摇匀,保证受热均匀｡样品在热处理之后应尽快转移进行冰浴｡花色苷含量及色泽在样品避光冷却1.0 h后测定｡1.2.4花色苷含量的测定采用差示分光光度法[13,14]｡具体操作如下,2 mL澄清待测液用pH值为1.0的缓冲液(125 mL 0.2 mol/L KCl与375 mL 0.2 mol/L HCl 混匀)稀释至25mL,另取2mL澄清待测液用pH值为4.5的缓冲液(400 mL 1 mol/L CH3CO2Na､240 mL 1 mol/L HCl与360 mL ddH2O混匀)稀释至25 mL,510 nm处测定吸光值A｡按下面公式计算含量,C=(A1-A2)×484.82×1 000×DF/24 825,其中,484.82是矢车菊-3-葡萄糖苷的分子量;24 825是矢车菊-3-葡萄糖苷在pH值为1.0缓冲液中510nm下的摩尔吸光系数;DF为稀释度;花色苷浓度C单位为mg/L;A1为用pH值为1.0的缓冲液稀释后样品的吸光值;A2为用pH值为4.5的缓冲液稀释后样品的吸光值｡1.2.5热降解动力学模型大多数研究表明,花色苷降解遵循一级反应动力学模式[15-18]｡因此,假定桑椹花色苷在含糖体系中亦是符合一级反应动力学的,反应速率常数(k)和半衰期(t1/2)可采用下面公式计算得出,ln(C/C0)=-k×t;t1/2=-ln1/2×(1/k)｡Arrhenius方程可以用来表明花色苷降解的温度依赖性｡活化能Ea和K0可以从一级反应速率常数的对数(lnk)对绝对温度的倒数(1/T)的作图中求出,k=K0 exp[-Ea/(R×T)];lnk=-Ea/(R×T)+lnK0｡其中,C0为花色苷初始浓度;C为在选择温度下加热t段时间后的花色苷浓度;k为反应速率常数(1/min);K0为频率常数(1/min);t为热处理时间(h);Ea为活化能(kJ/mol);R为气体常数,为8.314 kJ/(mol·K);T为绝对温度(K)｡2结果与分析2.1桑椹花色苷自身热降解动力学在不同的温度下加热后桑椹花色苷自身热降解动力学曲线如图1所示,lnC/C0与时间(t)之间的线性关系良好,表明桑椹花色苷自身热降解是符合一级反应动力学的,与多数研究报道相符[15-18]｡桑椹花色苷热处理过程中热降解动力学参数如表1所示｡可以看出,桑椹花色苷降解反应活化能为56.11 kJ/mol;随着温度升高,桑椹花色苷降解反应速率常数增大,半衰期减小,70℃下花色苷降解最慢,90℃下花色苷降解最快,其半衰期仅为70℃时的0.34｡2.2桑椹花色苷在葡萄糖体系中的热降解动力学分别在70､80､90℃时比较不同葡萄糖浓度(5%､10%､15%)对花色苷降解的影响,结果如图2-A､B､C所示｡70℃时采用一阶线性作图,lnC/C0与t之间的线性关系良好,r均大于0.98,可认为符合一级反应动力学｡而80､90℃时若采用一阶线性作图,其线性关系不好,不符合一级反应动力学｡花色苷降解反应速率不是恒定的,随加热时间的延长,反应速率常数k值逐渐增大,且葡萄糖的浓度越高,花色苷的降解速率也越大｡这可能是由于糖的热降解产物促进了花色苷的降解[9,19,20]｡花色苷的降解速率和糖本身生成糠醛等降解产物的速率有关｡当温度为70℃时,葡萄糖产生的热降解产物较少,对花色苷降解的影响也较小,因此花色苷降解仍呈一级反应动力学｡本研究与Tinsley和Daravingas[19,20]研究结果不符,他们的研究表明在糖存在情况下花色苷的降解仍然符合一级反应动力学｡这可能是由于实验所选择温度不同所造成的｡在他们的研究中,使用的温度为50℃,糖的热降解产物几乎没有形成,花色苷的降解速率很大程度上取决于花色苷自身的稳定性,而不是花色苷与热降解产物之间的反应｡因此,在糖存在的情况下,相对低温时花色苷的降解遵从一级反应动力学,而相对高温时(高于70℃)则遵从复杂反应动力学｡此外,据研究报道,高浓度糖可通过减小水活而降低花色苷降解速率[7],而本研究中并没有发现葡萄糖对花色苷热降解的保护作用,其原因可能是所选择葡萄糖浓度比较低,降低水活引起的保护作用不足以抵抗糖降解产物的促进作用,在低浓度时糖很可能对花色苷的降解有促进作用｡2.3桑椹花色苷在果糖体系中的热降解动力学分别在70､80､90℃条件下,比较不同浓度的果糖对桑椹花色苷降解的影响,结果如图3-A､B､C所示｡添加果糖后,花色苷的热降解均不再符合一级反应动力学;且花色苷随着温度增加降解速率不断加快;同时受到果糖浓度的影响,在一定范围内,随果糖浓度增加花色苷降解加快｡这与陈健初[21]报道的果糖在一定程度上能促进杨梅花色苷降解的结果相符｡比较图2和图3,可以看出果糖体系中花色苷的降解快于葡萄糖体系｡Rubinskiene[22]也曾经报道过果糖对花色苷降解的作用比葡萄糖大｡导致这种现象的原因,是己酮糖(果糖)比己醛糖(葡萄糖)更容易形成糠醛,而糠醛是引起花色苷降解的重要物质之一｡2.4桑椹花色苷在蔗糖体系中的热降解动力学蔗糖体系中花色苷的热降解如图4-A､B､C所示,亦可以看出其花色苷降解是不符合一级动力学的,同时随温度增加､蔗糖浓度增加,花色苷降解加快｡比较图2､3和4,蔗糖体系中花色苷的降解快于葡萄糖,而慢于果糖｡这可能是由于蔗糖是双糖,在形成糠醛之前需水解为葡萄糖和果糖[20],所以它所引起的降解速率介于果糖和葡萄糖之间｡2.5桑椹花色苷在不同糖体系中热降解动力学的比较图5表示80℃下花色苷分别在无糖以及添加浓度为15%的葡萄糖､果糖､蔗糖体系中花色苷的降解情况｡可以看出,糖在花色苷的降解中有两面性,在受热初始阶段,3条曲线在直线之上,即3个添加糖体系降解速率比花色苷自身降解速率慢;但是随着热反应的进行,3个体系的降解速率又远快于花色苷自身降解速率,糖又表现出明显的促进花色苷降解的作用｡这种两面性在所选择温度为80℃时最为明显｡在反应初期阶段,可能是由于糖的降低水活作用或增色效应对花色苷有保护作用,但是,反应1.0 h之后,可能由于糖在加热过程中形成的热降解产物糠醛等开始参与反应,因此添加糖的体系中花色苷的降解速率明显比无糖的花色苷自身体系快｡3结论本研究表明,桑椹花色苷自身的热降解符合一级反应动力学,但是当有葡萄糖､果糖和蔗糖存在情况下花色苷的降解不符合一级反应动力学(70℃时葡萄糖体系除外),其降解速率不是恒定的,在反应过程中花色苷的降解速率不断加快｡且研究结果表明各种糖对花色苷降解的促进作用依次为果糖>蔗糖>葡萄糖｡系统地研究不同糖体系中花色苷的降解情况,可进一步探索桑椹加工过程中花色苷降解机制,为开发防止桑椹加工过程中花色苷降解的新技术､新工艺提供了一些理论依据,同时也为其他富含花色苷的产品的加工提供了可借鉴的思路｡参考文献:[1] JACKMAN R L,YADA R Y,TUNG M A,et al. 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基片温度对Fe -N 化合物薄膜制备及磁性能的影响郭治天，韩奎（中国矿业大学理学院，江苏徐州221008）摘要：用X 射线衍射仪和振动样品磁强计研究了双离子束溅射法制备的Fe -N 薄膜的相组成和磁性能。
结果表明，基片温度对不同基片上制得的薄膜的结构和磁性能有显著影响。
基片温度为250C 和300C 时，在（111）硅片基片上制得无晶粒择优取向的单一!'-Fe 4N 相；基片温度为160C 时，可在玻璃基片上制得具有（100）面晶粒取向的单一!'-Fe 4N 相薄膜。
薄膜磁性测量表明，与无晶粒择优取向的!'-Fe 4N 相比较，具有（100）面晶粒取向的!'-Fe 4N 相的矫顽力较低，易达到磁饱和，但二者的饱和磁化强度基本一致。
关键词：基片温度；Fe -N 薄膜；晶粒取向；磁性能中图分类号：TM201.45文献标识码：A文章编号：1671-8887（2004）01-0024-04The Effects of Substrate Temperature on the Formation and Magnetic Properties of Fe -NCompound Thin FilmsGUO Zhi-tian ，HAN Kui(College of Science,China University of Mining and Technology,Xuzhou Jiangsu221008,China )Abstract :The structures and magnetic properties of the single !'-Fe 4N thin films prepared on by dual ionbeam sputtering have been studied using X -ray diffaction and VSM.The effects of substrate temperature on the structures and magnetic properties of the thin films were investigated.The single phase !'-Fe 4N film with the random crystal orientation was prepared when the substrate was Si (lll )at T s =250C &300C ,and the single phase !'-Fe 4N film with the (l00)plane crystal orientation was obtained on the glass substrate at T s =l60C.The magnetic properties of the thin films shows that compared with the !'-Fe 4N thin films with random orientation,The !'-Fe 4N thin films with (l00)crystal orientation have the lower coercive force and are seen to saturate easily.Key words :Substrate temperature;Fe -N thin films;crystal orientation;magnetic properties作者简介：郭治天(1964-),男，讲师，主要从事物理教学及材料科学方面的研究。
聚合物同质复合材料原位反应制备方法及其双相界面演化规律研究聚合物同质复合材料原位反应制备方法及其双相界面演化规律研究摘要：聚合物同质复合材料是一种新型的复合材料，由于具有高强度、高韧性等优异性能，被广泛应用于工业领域。
本文采用原位反应制备方法制备了一种聚合物同质复合材料，并研究了其双相界面演化规律。
实验结果表明，聚合物同质复合材料的双相界面演化规律受到温度、反应时间等因素的影响。
随着反应时间延长，双相界面的尺寸逐渐增大，界面密度逐渐减小。
在不同的温度下，双相界面的演化规律也不同。
本文的研究为聚合物同质复合材料的制备及其性能优化提供了理论基础和实验依据。
关键词：聚合物同质复合材料，原位反应制备，双相界面演化规律，温度，反应时间Introduction:Polymer homogenous composite materials have been widely usedin industrial fields due to their excellent properties suchas high strength and toughness. In this paper, a polymer homogenous composite material was prepared by in-situreaction method, and the evolution law of its two-phase interface was studied. The experimental results show that the evolution law of the two-phase interface of the polymer homogenous composite material is affected by factors such astemperature and reaction time. With the prolongation of reaction time, the size of the two-phase interface gradually increases, and the interface density gradually decreases. At different temperatures, the evolution law of the two-phase interface is also different. The study provides a theoretical basis and experimental basis for the preparation and performance optimization of polymer homogenous composite materials.Method:The polymer homogenous composite material was prepared by in-situ reaction method. The reactants were mixed and placed in a mold, and then heated to a certain temperature and maintained for a certain period of time to complete the reaction. The samples were then taken out and analyzed. The size and density of the two-phase interface were measured by scanning electron microscopy (SEM) and image analysis software.Result:The experimental results show that the evolution law of the two-phase interface of the polymer homogenous composite material is affected by factors such as temperature and reaction time. With the prolongation of reaction time, the size of the two-phase interface gradually increases, and the interface density gradually decreases. At different temperatures, the evolution law of the two-phase interface is also different. When the temperature is high, the interface size is large, the interface density is low, and theinterfacial contact is loose. When the temperature is low, the interface size is small, the interface density is high, and the interfacial contact is tight.Conclusion:The in-situ reaction method can be used to prepare polymer homogenous composite materials with controlled two-phase interface structure. The evolution law of the two-phase interface of the polymer homogenous composite material is affected by factors such as temperature and reaction time. The study provides a theoretical basis and experimental basis for the preparation and performance optimization of polymer homogenous composite materials.Keywords:polymer homogenous composite material, in-situ reaction method, evolution law of two-phase interface, temperature, reaction time.Polymer homogenous composite materials have attracted increasing attention due to their unique properties and potential applications in various fields. The in-situ reaction method is an effective approach to prepare such materials, which involves the simultaneous polymerization of monomers and the dispersion of fillers. The resulting polymer matrix and filler particles are intimately bonded at the molecular level, leading to enhanced mechanical, thermal, electrical, and other properties.The two-phase interface structure is a crucial factor that determines the overall performance of polymer homogenous composite materials. It refers to the boundary between the polymer matrix and filler particles, which can have different shapes, sizes, orientations, and chemical compositions. The evolution law of the two-phase interface is affected byvarious factors, including temperature and reaction time.Temperature plays a critical role in the in-situ reaction process, as it affects the reaction kinetics, polymerization rate, viscosity, and phase behavior of the system. When the temperature is too low, the reaction may proceed slowly, resulting in incomplete polymerization and poor interfacial adhesion. On the other hand, when the temperature is too high, the reaction may become uncontrollable, leading to thermal degradation, agglomeration, and other defects. Therefore, itis essential to optimize the temperature condition for thein-situ reaction of polymer homogenous composite materials.Reaction time also influences the two-phase interfacestructure of polymer homogenous composite materials. Itrefers to the duration of the in-situ reaction process, which can affect the degree of polymerization, filler dispersion, and interfacial bonding. Generally, a longer reaction timecan lead to a more complete polymerization and a higherdegree of filler dispersion, resulting in a more uniform and dense two-phase interface structure. However, excessive reaction time may also cause polymer degradation, filler aggregation, and other undesirable effects.In summary, the evolution law of the two-phase interfacestructure of polymer homogenous composite materials is a complex and dynamic process that depends on various factors, including temperature and reaction time. By understanding and controlling these factors, it is possible to tailor the properties and performance of polymer homogenous composite materials for specific applications.Another factor that can affect the evolution law of the two-phase interface structure is the composition of the polymer homogenous composite. Different types and concentrations of fillers or additives may have different effects on the interface structure, as well as on the overall properties and performance of the material.For example, adding nanoparticles to a polymer matrix can improve the mechanical, thermal, and electrical properties of the composite material. However, the interaction between the nanoparticles and the polymer may also affect the interface structure, leading to changes in the dispersion and aggregation of the particles.Similarly, adding fibers or other reinforcements to a polymer matrix can enhance the strength and stiffness of the composite, but may also affect the interface structure through interfacial bonding, stress transfer, and other mechanisms.Overall, the evolution law of the two-phase interface structure in polymer homogenous composite materials is a complex and multifaceted process that involves various physical, chemical, and mechanical factors. Understanding andcontrolling these factors can help to optimize the properties and performance of the materials for specific applications, ranging from aerospace and automotive to biomedical and electronics.To further understand the evolution law of the two-phase interface structure in polymer homogenous composite materials, one must consider the effect of processing parameters. The processing route can play a major role in modifying the interface structure and the mechanical properties of the composite material. For example, in extrusion, the high shear forces experienced by the composite result in changes in the orientation of the reinforcing fibers and the distribution of the filler particles, leading to a modified interfacial structure.Another factor to consider is the effect of environmental exposure on the interface structure and properties of the composite material. Exposure to heat, moisture, and UV radiation can cause damage to the interface, including debonding, delamination, and fracture. These effects can be compounded by the presence of impurities and contaminants, which can weaken the interface further.To mitigate these issues, various reinforcement techniques have been developed to improve the bonding and stresstransfer across the interface. Examples of such techniques include coupling agents, surface treatments, and interphase modifiers. These techniques involve modifying the chemicaland physical properties of the interface to enhance its strength and durability.In addition, advances in computational modeling and simulation have enabled researchers to better understand the complex interactions between the different factors affecting the interface structure and performance of polymer homogenous composite materials. Digital modeling techniques such asfinite element analysis and molecular dynamics simulations have allowed scientists to investigate the effects of different processing and environmental conditions on the interface structure and predict the behavior of the composite material under various loading conditions.In summary, the evolution law of the two-phase interface structure in polymer homogenous composite materials is a complex and multifaceted process that involves various physical, chemical, and mechanical factors. Understanding and controlling these factors can help to optimize the properties and performance of the materials for specific applications. With continued research and development, polymer homogenous composite materials have the potential to revolutionize the field of materials science and engineering.To achieve optimal properties and performance, the two-phase interface structure of polymer homogenous composite materials must be carefully studied and understood. The interface structure is determined by a variety of factors, including the nature and properties of the polymer matrix, the type and characteristics of the reinforcing phase, the method of fabrication, and the processing conditions.One key factor that affects the interface structure is thetype and properties of the polymer matrix. Different polymers have different chemical and physical properties that can affect the level of interaction between the matrix and the reinforcing phase. For example, the presence of polar functional groups in the matrix can increase the strength of interfacial bonding, while the absence of such groups can lead to weak or ineffective bonding.In addition to the matrix properties, the nature and characteristics of the reinforcing phase also play an important role in determining the interface structure. Different types of reinforcing materials, such as fibers, particles, or plates, have different sizes, shapes, and surface properties that can influence the level of adhesion and compatibility with the matrix.The method of fabrication and processing conditions can also significantly affect the interface structure. Various processing techniques, such as extrusion, injection molding, or compression molding, can influence the level of shear and deformation experienced by the reinforcing phase, which can in turn affect the interface morphology and properties. It is also important to ensure that the processing conditions are optimized to achieve uniform dispersion and orientation of the reinforcing phase throughout the matrix.To achieve the desired interface structure and properties, several approaches can be taken. One approach is to modify the matrix or reinforcing phase to enhance the level of interaction and bonding between the two phases. For example, functionalizing the matrix with polar groups or modifying thesurface of the reinforcing phase with coupling agents can increase the level of adhesion and compatibility between the phases.Another approach is to tailor the processing conditions to optimize the interface structure. By carefully controlling the temperature, pressure, and other processing parameters, the level of shear and deformation experienced by the reinforcing phase can be controlled, leading to uniform dispersion and orientation within the matrix.In conclusion, understanding and controlling the factors that influence the interface structure in polymer homogenous composite materials is critical for achieving optimal properties and performance. With continued research and development, these materials have the potential to revolutionize the field of materials science and engineering, leading to new and improved applications in various industries.Furthermore, polymer homogenous composites have the potential to address sustainability and environmental concerns in industries. Traditional materials, such as metals and concrete, have a significant environmental footprint due to their high energy consumption and greenhouse gas emissions during production. In contrast, polymers are lightweight and have lower energy requirements during manufacturing. Therefore, the use of polymer composites may reduce the overall energy consumption and environmental impact in many applications.Moreover, polymer composites offer exceptional design flexibility, enabling the production of complex shapes and structures that are difficult to achieve with traditional materials. This design freedom is particularly useful for aerospace and automotive industries, where the use of lightweight and strong materials is essential. Additionally, the use of polymer composites in medical applications, suchas implantable devices and prosthetics, offers patientsbetter quality of life and faster recovery times.Despite their many advantages, there are still somechallenges that need to be addressed in the development and application of polymer homogenous composites. One of these challenges is ensuring the long-term durability of these materials. Polymeric materials are known to degrade over time, especially when exposed to UV radiation, heat, and moisture. Therefore, it is critical to develop composite materials with long-term durability and stability.Additionally, the cost of producing polymer homogenous composites is higher than traditional materials, mainly dueto the high cost of raw materials and manufacturing equipment. However, with advancements in technology and economies of scale, the cost of production is expected to decrease over time.In conclusion, polymer homogenous composites offer apromising alternative to traditional materials, with unique properties and design flexibility. To achieve their full potential, continued research and development are necessaryto address the challenges and limitations of these materials.One area of research that could greatly benefit from the useof polymer homogenous composites is the transportation industry. By replacing traditional materials with composites, vehicles could become lighter, more fuel-efficient, and more environmentally friendly. However, there are still hurdles to overcome in terms of cost-effectiveness, durability, and recyclability.Another area where polymer homogenous composites could be useful is in the construction industry. By using composites instead of traditional materials like steel or concrete, buildings could become more earthquake-resistant and have increased durability over time. However, issues such as fire resistance, availability of raw materials, and cost-effectiveness must be addressed before these materials can become widely adopted in the construction industry.Overall, polymer homogenous composites have the potential to revolutionize industries such as transportation and construction. However, continued research and development are necessary to overcome current limitations and address new challenges that arise along the way. With the potential benefits of these materials, it is certainly worth investingin further research and development to unlock their full potential.In conclusion, polymer homogenous composites offer several advantages such as high strength, lightweight, and durability, making them suitable for various industries. However, their adoption is still limited due to challenges such as high production costs, difficulty in recycling, and limitedversatility. Continued research and development are necessary to overcome these challenges and improve the performance of these materials. With their potential to revolutionize industries such as transportation and construction, it is worth investing in further research to unlock their full potential.。
对苯二甲醛分解温度对苯二甲醛分解温度的探讨1. 引言1.1 简介对苯二甲醛是一种常见的有机化合物，具有广泛的应用领域，包括材料科学、化学工程以及有机合成等领域。
1.2 主题介绍本文将深入探讨对苯二甲醛的分解温度，旨在为读者提供全面、深入和灵活的理解。
2. 对苯二甲醛的性质2.1 分子结构对苯二甲醛的化学式为C8H6O2，分子结构中含有两个苯环和一个甲醛基团，具有较高的分子量和丰富的化学反应活性。
2.2 物理性质对苯二甲醛是一种无色结晶固体，具有特殊的香气和温暖的味道，在常温下可以稳定存在。
它几乎不溶于水，但可以溶于有机溶剂。
2.3 化学性质对苯二甲醛在高温和光照的条件下容易发生分解反应，形成一系列副产物，其中分解温度是对苯二甲醛稳定性的一个重要指标。
3. 对苯二甲醛的分解温度和稳定性3.1 分解反应对苯二甲醛的分解反应是一个复杂的过程，涉及多种反应路径和中间产物。
其中主要的分解路径包括热分解、光照分解和酸催化分解等。
3.2 影响因素对苯二甲醛分解温度受多种因素影响，包括温度、光照、催化剂和溶剂等。
温度是影响分解的最重要因素，一般情况下，随着温度的升高，分解反应速率也会增加。
3.3 动力学和热力学对苯二甲醛的分解反应可通过动力学和热力学参数进行描述。
动力学参数包括反应速率常数和反应级数，热力学参数则包括反应焓和反应熵等。
4. 实验方法和结果4.1 实验方法测定对苯二甲醛的分解温度可以采用多种方法，包括热重分析、差示扫描量热法和红外光谱等。
这些方法可以通过监测样品质量、吸热和产物生成等参数来确定分解温度。
4.2 实验结果根据相关文献报道，对苯二甲醛的分解温度通常在200-300摄氏度范围内。
具体数值会受到实验条件、溶剂和催化剂等因素的影响。
5. 观点和理解5.1 观点对苯二甲醛的分解温度是该化合物稳定性的重要指标，可以通过合适的实验方法进行测定。
研究分解温度有助于了解该化合物的性质和应用潜力。
5.2 理解通过本文的探讨，可以看出对苯二甲醛的分解温度是受到多种因素影响的复杂反应过程。
Kinetics of Thermal Degradation of Thermotropic Poly(p-oxybenzoate-co-ethylene-2,6-naphthalate)by Single Heating Rate MethodsLi Zhang,1Jinghong Ma,1Xinyuan Zhu,2Borun Liang11State Key Lab of Modification of Chemical Fiber&Polymer Material,Donghua University,Shanghai,200051,China 2College of Chemistry and Chemical Technology,Shanghai Jiao Tong University,Shanghai,200240,ChinaReceived7August2003;accepted8September2003ABSTRACT:The kinetics of thermal degradation of ther-motropic liquid crystalline poly(p-oxybenzoate-co-ethylene-2,6-naphthalate)(PHB/PEN)with the monomer ratio of60: 40and PEN in nitrogen was studied by dynamic thermo-gravimetry(TG).The kinetic parameters,including the ac-tivation energy E a,the reaction order n,and the frequency factor ln(Z)of the degradation reaction for PHB/PEN(60: 40)and PEN were analyzed by the single heating rate meth-ods of Friedman and Chang.The effects of the heating rate and the calculating method on the thermostable and degra-dation kinetic parameters are systematically discussed.©2004Wiley Periodicals,Inc.J Appl Polym Sci91:3915–3920,2004 Key words:poly(p-oxybenzoate-co-ethylene2,6-naphtha-late);liquid crystalline polyester;thermal degradation;ther-mogravimetry;kinetics;thermostabilityINTRODUCTIONPoly(oxybenzoate-co-ethylene terephthalate)(PHB/ PET)copolymer,is a well-known and commercially available liquid crystalline polymer,which has been studied extensively over the past years.1–4Poly(ethyl-ene-2,6-naphthalate)(PEN)is a slow-crystallizing polymer.5–7The naphthalene moiety in PEN provides more stiffness than PET to the linear polymer back-bone,leading to improved thermal resistance;excel-lent mechanical properties,such as tensile properties and dimensional stability;and outstanding gas barrier characteristics.PHB/PEN copolymer might have more applications and letter properties than PHB/ PET copolymer.Hitherto,no attention has been given to its thermal degradation behavior.Thermal stability of a polymeric material is one of the most important properties for both processing and application.Thermogravimetry(TG)is a technique widely used to characterize thermal degradation of polymer materials.In this article,TG and differential thermogravimetry(DTG)measurements of PHB/PEN polymer are reported;the thermal degradation tem-perature and the kinetics of PHB/PEN copolymer with the monomer mole ratio,PHB/PEN(60:40),and PEN were studied by two kinds of calculating meth-ods through nonisothermal TG thermograms.The de-pendencies of the degradation temperature and ki-netic parameters on the heating rate and calculating method are discussed in detail.EXPERIMENTALPHB/PEN polymer with the structural formula shown in Scheme1was synthesized following the procedure described elsewhere.8,9The intrinsic viscos-ity of the PHB/PEN polymer was measured at0.5% concentration in phenol/1,1,2,2-tetrachloroethane(1: 1,w/w)at25°C.The TG and DTG thermograms were obtained by using a Perkin–Elmer7series analyzer under a dy-namic nitrogen atmosphereflowing at50ml/min, varying heating rate from5to45K/min,while the sample weights were kept at1.0Ϯ0.1mg.There are several methods(proposed by Fried-man,10Freeman and Carroll,11Chang,12Flynn and Wall,13Chaterjee and Conrad,14Horowitz and Metzger,15Kissinger,16Coats and Redfern,17Van Krevelen,18Reich,19and Ozawa20)for calculating ki-netic parameters that depend not only on the experi-mental conditions but also on the mathematical treat-ment of the data.We will use the Friedman and Chang methods to evaluate the activation energy E␣the re-action order n,and the frequency factor Z based on a single heating rate measurement without making any assumptions.Detailed descriptions of the two meth-ods are not given because the methods for evaluating the kinetic parameters from TG/DTG traces are easily available from the literature.10,12The equations em-ployed in the methods are listed below.Correspondence to:L.Zhang.Journal of Applied Polymer Science,Vol.91,3915–3920(2004)©2004Wiley Periodicals,Inc.Friedman method10ln͑Z͒ϭln͑d␣/dt͒Ϫn ln͑1Ϫ␣͒ϩE a/͑RT͒(1) where␣is the weight loss of the polymer undergoing degradation at time t;R is the gas constant(8.3136J molϪ1KϪ1),and T is the absolute temperature(K);Z, n,E a are the frequency factor,the order,and the acti-vation energy of the thermal degradation reaction, respectively.The plot of ln(d␣/dt)versus l/T should be linear withϪE a/R as the slope.Additionally,the E a/(n R)value could be determined from the slope of the linear plot of ln(1Ϫ␣)versus l/T.Chang method12Equation(1)can be rewritten in the following form: ln͓͑d␣/dt͒/͑1Ϫ␣͒n͔ϭln͑Z͒ϪE a/͑R T͒(2) A plot of ln[(d␣/dt)/(1Ϫ␣)n]against1/T will yield a straight line if the degradation order n is selected correctly.The slope and intercept of this line will provide theϪE a/R and ln(Z)value,respectively.RESULTS AND DISCUSSIONThe TG and DTG curves of PHB/PEN(60:40)and PEN in nitrogen at heating rates of10,15,20,30,35,45and5,10,15,20,30,35K/min are shown,respectively,in Figures1and2.The DTG curves of PHB/PEN(60:40)and PEN indicate that only one weight-loss stage occurs during degradation.PHB/PET copolymer with monomer mole ratio60:40shows two weight-loss stages in nitrogen at low heating rates(1and2K/min).Gener-ally,in the case of random copolymer,stepwise deg-radation of individual A and B homopolymer seg-ments may merge into one-step degradation.The maximum degradation temperature of the random copolymer mediates between the maximum degrada-tion temperatures of the two corresponding ho-mopolymers.For stepwise degradation of individual A and B segments in block copolymer,however,the maximum degradation temperatures get close to each other.4The degradation behavior of the PHB/PEN poly-mer under nitrogen is quite different from that of the respective PHB or PEN homopolymers.The TG re-sults obtained and discussed so far could be taken as proof of the presence of a random sequence distribu-tion in the polymer backbone because no distinct peaks representative of thermal degradation of indi-vidual PHB and PEN homopolymers are observed during the thermal degradation of the PHB/PEN polymer.In the case of random copolymer,generally stepwise degradation of individual PHB and PEN ho-mopolymer segments merge into single steps located in between the maximum degradation temperatures of the corresponding homopolymers.Kinetics of nonisothermal degradation analyzed by single heating rate methodsAll of the methods can determine the kinetic param-eters for the thermal degradation of PHB/PEN(60: 40)and PEN by using only one heating rate.Figures3 Figure1Dynamic TG curves at six heating rates in nitrogen:(a)PHB/PEN(60:40);(b)PEN.Scheme13916ZHANG ET AL.and 4show the relationship given by eq.(1)of the Friedman method.Figure 5shows the relationship proposed by Chang where the degradation orders are assumed to be 1.2–1.7for PHB/PEN (60:40)and 0.7–1.6for PEN.Be-cause the lines of ln[(d ␣/dt )/(1Ϫ␣)n ]versus 1/T overlapped each other,the Waterfall Graph (in Micro-cal Origin version 5.0,Microcal Software,Inc.,Northampton,MA)was used to obtain a distinct view.Each dataset is displayed as a line data plot,which is offset by a specified amount in both the X and Y directions.For the Chang method,the absolute XandFigure 2Dynamic DTG curves at six heating rates in nitrogen:(a)PHB/PEN (60:40);(b)PEN.Figure 3Friedman plots of ln(d ␣/dt )or ln(1Ϫ␣)versus 1/T for PHB/PEN (60:40)in nitrogen at six heatingrates.Figure 4Friedman plots of ln(d ␣/dt )or ln(1Ϫ␣)versus 1/T for PEN in nitrogen at six heating rates.KINETICS BY SINGLE HEATING RATE METHODS 3917Y values do not affect the calculation of thermal deg-radation kinetic parameters,so the offset X -and Y -axes are omitted here.Figure 6shows the relationship between the maxi-mum weight loss rate (d ␣/dt )m and heating rate for PHB/PEN (60:40)and PEN.The kinetic parameters calculated by the two single heating rate methods for the PHB/PEN (60:40)are summarized in Table I.The data for the PEN are listed in Table II.The effect of heating rateFrom Table I,it can be concluded that the kinetic parameters of PHB/PEN (60:40)change with the heating rate.Most of E a ,ln(Z),T d ,and T dm values increase significantly with heating rate,whereas the n values stay roughly the same as the heating rate changes from 10to 45K/min.That is to say,when theheating rate is high enough,the effect of the concen-tration of degradation products from PHB/PEN (60:40)on thermal degradation reaction will remain roughly unchanged.From Table II it can be seen that the variation of the E a ,ln(Z ),T d ,and T dm for PEN with heating rate is similar to that of PHB/PEN (60:40).The reaction order n varies little with the heating rates adopted in this article.Additionally,Figure 6shows (d ␣/dt )m values in-crease linearly with heating rate for PHB/PEN (60:40)and PEN.Generally,the variation of these kinetic parameters reveals the change of thermal degradation mechanism (i.e.,transformation from the diffusion-controlled ki-netics into the decomposition-controlled kinetics,or vice versa).21At lower heating rates,the diffusion of the degradation products apparently does not affect the kinetics of the degradation process,so kinetic pa-rameter values were found to be lower.Alternatively,at a higher heating rate,the decomposition of the polymer is probably faster than the diffusion of the degradation products through the polymer melt;therefore,the kinetics of the degradation process are under diffusion control of degradation products.Con-sequently,higher kinetic parameters were observed with increasing heating rate.4Additionally,there are some differences in the ki-netic data calculated by using the different methods,as shown in Tables I and II.The Friedman method gave lower E a values but higher n values of the two methods.As shown in Figure 5,the Chang method actually tends to form straight lines in the widest temperature range,which means a smaller error in the calculation of the kinetic parameters by this method.However,the temperature range used for the deter-mination of the kinetic parameters by the Friedman method is wide enough to obtain reliableresults.Figure 5Chang plots of ln[(d ␣/dt )/(1Ϫ␣)n ]versus 1/T for the thermal degradation in nitrogen at six heating rates:(a)PHB/PEN (60:40);(b)PEN.Figure 6Effect of heating rate on the maximum decompo-sition rate.3918ZHANG ET AL.Thermal stabilityNo matter which method was used above,the funda-mental equation is the same:d␣/dtϭZ͑1Ϫ␣͒n exp[ϪE a/͑R T͒](3) Because the value of(1Ϫ␣)is always less or equal to 1,d␣/dt decreases with increasing n,and the zero order(nϭ0)characterizes the most rapid degradation reaction.4From eq.(3),it can be concluded that higher n and E a values or a lower Z value results in a lower d␣/dt value,which means higher thermal stability. As shown in Tables I and II,the average n,T d,and T dm values calculated from the heating rate for PHB/ PEN(60:40)are larger than those for PEN,whereas(d ␣/dt)m and ln(Z)values at different heating rates for PHB/PEN(60:40)are lower than those for PEN.This may be attributed to the difference between PHB/ PEN(60:40)and PEN in molecular structures.It has been mentioned that the higher the n value,the slower the degradation.More aromatic carbon atoms(or less hydrogen atom)will decrease the thermal degradation rate and increase thermal stability.PHB/PEN(60:40) possesses a higher n value and lower degradation rate than PEN because of the existence of PHB units.On the contrary,the average E a value calculated from the heating rate is lower than that for PEN.This could be attributed to the effect of molecular weight.In the melt polycondensation process,PEN degradesfirst and then copolymerizes with p-acetoxybenzoic acid.Be-cause of the poor copolymerization ability,long blocks of PHB units formed,which may increase the melt viscosity greatly and may make further polyconden-sation become impossible in the melt state.So,PHB/ PEN(60:40)studied here,which was obtained through melt polycondensation,has lower molecular weight than PEN.It is evident that the lower the molecular weight,the more the end groups.End groups can initiate thermal degradation.4As a result, lower molecular weight leads to a lower E a value. Therefore,a higher E a value would be obtained if the molecular weight of PHB/PEN(60:40)could be increased through solid-state polymerization.CONCLUSIONSOn the basis of TG and DTG results obtained at a single heating rate,some important kinetic parametersTABLE IKinetic Parameters of Thermal Degradation of PHB/PEN(60:40)Under Nitrogen Calculatedby Two Single Heating Rate MethodsHeatingrate(K/min)T d/T dm(°C)Friedman Chang Average aE a(KJ/mol)nln(Z)(minϪ1)E a(KJ/mol)nln(Z)(minϪ1)E a(KJ/mol)nln(Z)(minϪ1)10420.47/452.87216 1.439.2236 1.242.8226 1.341.0 15423.07/456.14223 1.640.7238 1.643.4231 1.642.1 20425.85/463.12234 1.541.9227 1.741.2231 1.641.6 30427.19/464.45218 1.540.0244 1.744.8231 1.642.4 35431.21/469.74240 1.743.8247 1.745.1244 1.744.5 45432.65/470.41237 1.542.5226 1.741.5232 1.642.0 Average b426.74/462.79228 1.541.4236 1.643.1232 1.642.3a Calculated with different analyzed methods.b Calculated with the heating rate ranging from10to45K/min.TABLE IIKinetic Parameters of Thermal Degradation of PEN under Nitrogen Calculated by Two Single Heating Rate MethodsHeatingrate(K/min)T d/T dm(°C)Friedman Chang Average aE a(KJ/mol)nln(Z)(minϪ1)E a(KJ/mol)nln(Z)(minϪ1)E a(KJ/mol)nln(Z)(minϪ1)5401.85/429.682350.942.72530.746.22440.844.5 10405.87/438.66235 1.142.4254 1.046.3245 1.144.4 15418.64/448.58243 1.544.3270 1.449.2257 1.546.8 20420.45/449.74251 1.646.0270 1.549.3261 1.647.7 30421.63/456.10268 1.648.8272 1.649.9270 1.649.4 35423.90/456.69263 1.748.1272 1.650.0268 1.749.1 Average b415.39/446.58249 1.445.4265 1.348.5257 1.447.0a Calculated with different analyzed methods.b Calculated with the heating rate ranging from5to35K/min.KINETICS BY SINGLE HEATING RATE METHODS3919of thermal degradation for the thermotropic liquid crystalline PHB/PEN(60:40),such as the activation energy,the degradation order,and the frequency fac-tor,have been calculated by the Friedman and Chang methods.The kinetic parameters exhibit a dependence on molecular weight,heating rate,and method of calculation.The degradation seems to be a random scission process of the ester linkages.Compared with PEN,PHB/PEN(60:40)has higher T d,T dm,and n,but lower(d␣/dt)m,E a,and ln(Z).All these parameters except for E a indicate that PHB/PEN (60:40)is more heat stable than PEN.The T d,T dm,and (d␣/dt)m values,as well as E a and ln(Z)values derived from single heating rate methods,increase signifi-cantly with heating rates.References1.Jackson,W.J.;Kuhfuss,H.F.J Polym Sci,Polym Chem Ed1976,14,2043.2.Bohme,F.;Komber,H.;Leistner,D.;Ratzsch,M.MacromolChem Phys1994,195,3233.3.Shinn,T.H.;Chen,J.Y.,Lin,C.C.J Polym Sci1993,47,1233.4.Li,X.-G.;Huang,M.-R.;Guan,G.-H.;Sun,T.Polym Int1998,46,289.5.Buchner,S.;Wiswe,D.;Zachmann,H.G.Polymer1989,30,480.6.Jager,J.A.;Juijn,C.J.M.;Van Den Heuvel.J Appl Polym Sci1995,57,1429.7.Cakmak,M.;Kim,J.C.J Appl Polym Sci1997,64,729.8.Guo,M.;Zachmann,H.G.Polymer1993,34,2503.9.Guo,M.;Brittain,W.J.Macromolecules1998,31,7166.10.Friedman,H.L.,J Polym Sci,Part C:Polym Lett1964,6,183.11.Freeman,E.S.Carroll,B.,J Phys Chem1958,62,394.12.Chang,W.L.J Appl.Polym Sci1994,53,1759.13.Flynn,J.H.;Wall,L.A.J Polym Sci,Part B:Poly Phys1966,4,323.14.Chaterjee,P.K.;Conrad,C.M.J Polym Sci,Part A:Poly Chem1968,6,594.15.Horowitz,H.H.;Metzger,G.Anal Chem1963,35,1464.16.Kissinger,H.E.Anal Chem1957,29,1702.17.Coats,A.W.;Redfern,J.P.Nature1964,201,68.18.Van Krevelen,D.W.;Van Heerden,C.Huntjens,F.J.Fuel1951,30,11.19.Reich,L.J Polym Sci Polym Lett Ed1964,2,621.20.Ozawa,T.Bull Chem Soc Jpn1965,38,1881.21.Li,X.-G.;Huang,M.-R.Polym Degrad Stab1999,64,81.3920ZHANG ET AL.。
