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材料科学与工程导论1 Polymerization (聚合作用)is the process by which small molecules (分子) consisting of one unit or a few units are chemically joined to create these giant molecules. Those small molecule units are called _____A) polymers B) monomers (单体) C) oligomers D)elastomerscable.A)For automobile bumper, the best choice of polymer is Natural Rubber.B)For mineral water bottle, the best choice of polymer is Low-Density (密度) Polyethylene (聚乙烯)C)For insulating cable, the best choice of polymer is polystyrene (聚苯乙烯).D)For mineral water bottle^ the best choice of polymer is Polyethylene Terephthalate.3)In general, for a given type of thermoplastic (热塑性塑胶)the tensile (可延展的) strength, creep resistance impact toughness, wear resistance, and melting temperature all increase with _______A) degree of polymerization B)density of branching C)tacticity D) crystallinity4)ABS, composed of acrylonitrile, butadiene, and styrene (苯乙烯)，is one of the most common polymer materials. Styrene and acrylonitrile form a liner copolymer (异量分子聚合物)(SNA) that serves as a matrix. Styrene and butadiene also form a liner copolymer, BS rubber, which acts as the __________ material.D or B?A)fire retardant B) filler C) cross-linking D)plasticizer5)Epoxies (环氧树月旨)are thermosetting polymers formed from molecules containinga tight C-O-C ring. During polymerization, the C-O-C rings are opened and the bonds are rearranged to join the molecules. If epoxy is used as an adhesive (粘齐ll) for a variety of applications, which kind of adhesives does it belong to?A)Chemically Reactive AdhesivesB)Evaporation or Diffusion AdhesivesC)Hot-Melt Adhesives D) Pressure-Sensitive Adhesives6)What area the major advantages associated with plastic compared to ceramics(陶瓷)，glasses, and metallic materials?A)lightweight and corrosion(铁锈,腐蚀卜resistantB)high strength and high-temperature resistantC)high-temperature resistant and insulatingD)high stiffness and corrosion-resistant7)Which one is not a thermoset polymer?A) Polyethylene B) Natural Rubber C) Epoxy D) Phenolic8)Depending on the degree of cross-linking, the polyurethanes behave as thermosetting polymers, thermoplastics (热塑性塑胶)，or elastomers. These polymers find application as fibers, coatings, and foams for furniture, mattress, and insulation. Why polyurethanes are versatile(为什么聚氨酯是通用的)？A) for their polar repeat unit B) for their linear structureC) for their multi-functional monomer D) for their tactictity structure9) Liquid Crystalline(透明的)Polymers are polymers which behave as _____A) liquid B) thermoplastic C) thernoset D) oriented (取向)rods10) The glass temperature (Tg) is typically about ______ t imes the absolute melting temperature (Tm).A) 0.2 to 0.3 B) 0.5 to 0.7 C) 0.8 to 1.0 D) 1.0 to 2.011) Most thermoplastic exhibit a non-Newtonian and visicoelastic behavio 匸 The stressand train are not linearly related for most parts of the stress-strain curve. The viscoelastic behavior means when an external (夕卜部的)force is applied to a B) both elastic and plastic (塑性) C) only plastic D) neither elastic nor plastic12) Compare the tensile strength of LDPE, HDPE, PVE, PP, and arrange them in sequence (顺序)from high strength to low tensile strength•A) LOPE>HDPE>PVE>PP B) LDPE>HDPE>PP>PVCC) PVC>PP>HDPE>LDPE D) PVC>HDPE>PP>LDPE13) Degree of polymerization is usually used to characterize _______A) cross-linking network B) thermosetting polymerC) polymer degradation D) thermoplastic polymer14) Silicones (硅)are important elastomer based on chains composed of silicon and oxygen atoms. The silicone rubbers provide high-temperature resistance, permitting use of the elastomer at temperature as high as ____________ °C. Low molecular weight silicones form liquids and are known as silicon oils.A) 100 B) 150 C) 200 D) 30015) There are a lot of thermoplastic processing methods, typical forming processincludes: extrusion, blow molding, injection molding, thermoforming, calendaring and spinning ・ If we want to produce sping water bottles, which processing way is best choice?A) extrusion 挤ill 成型 B) blow molding 吹塑成型 C) injection molding 注射成型D) thermoforming 热成型16) The recycling of thermoplastics is relatively easy and practiced widely. Many of the everyday plastic products you encounter (bags, soda bottles, yogurt containers, etc.) have numbers stamped on them. For PRT products, the number is 1. For HOPE and LDPE, the numbers are __________ ，respectively. Other plastics are marked number 7,A) 3 and 4 B) 4 and 5 C) 2 and 4 D) 2 and 317) The temperature above which a polymer burns, chars, or decompose. Which team is appropriately used in describing the remperature ・A) Tg B)Td C) Tm D) HDT18) Which forming process is not a best choice for thermosetting polymers.A) Compression molding B)transfer moldingC) reaction injection D) spinning19) Elastomers are thermoplastics or lightly cross-linked thermosets that exhibitthermoplastic _ A) only elasticdeformation occurs.greater than ______ elastic deformation.A) 0.2% B)2% C) 20% D)200°/o20)Thermoplastic elastomers combine feature of both thermoplastics and elastomers. At high temperature, these polymers behave as __________ and are plastically into shapes, at how temperature, they behave as ________A) thermoplastics; elastomers B) thermoplastics; thermosetting polymersC) elastomers; thermoplastic D) elastomers; thermosetting polymers21 Define (a) a thermoplastic, (b) thermosetting plastics, (c) elastomers, and (d) thermoplastic elastomers.Thermoplastics :热后可塑性物质是由一些单体聚合成长链组成，它们代表性的特性是可塑性，延展性。
