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Modern Material Science And Engineering 2

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Refers to the spatial geometry of the main chain carbon and substituents that can be changed by rotation and flexural motion






2. Occurs when substituent are directly aligned - causing substantial repulsion between the substituents and an unfavorable conformation.






3. Part of the extrusion apparatus that hols a large quantity of polymer pellets as they are fed into the barrel






4. All issues related to bonding in polymers including primary and secondary bonding - branching - formations of networks - and end groups






5. Porcess of breaking large organic hydrocarbons into smaller molecules






6. Two substituents found at both ends of a polymer chain - which have little to no effect on mechanical properties






7. Polymers with low melting poins due to the lack of covalent bonding between adjacent chains. such polymers can be repeatedly melted and re- formed






8. Primary raw material for most polymers






9. Polymer made up of two of more differenet monomers covalently bonded together






10. Terminating a condensation/step- growth polymerization reaction by adding a material with only one functional group






11. Conformation that occurs when the largest substituent in a molecule are offset by 60






12. Conformation in which the largest substituents are offset by 180






13. Kevlar - Twaron - high tensile strength - lightweight - susceptible to uv degradation - nonconductive - bullet- resistant armor - sports equipment - fire resistance






14. Final step in the polymerization process - which causes the elongation of the polymer chain to come to an end






15. Formation of a polymer that occurs when two potentially reactive end groups on a polymer react to form a new covalent bond between the polymer chain. this reaction also forms a byproduct - which is typically water






16. Process by which chemical cross - linkages can form between adjacent polymer chains - strengthening the material without significantly damaging its elastic properties






17. Atoms attached to the polymer backbone.






18. Polymers that can stretch by 200% or more and still return to their original length when released; polyurethatnes and the aliphatic thermosets(rubbers)






19. Stiff and extremely inert polymer - low cost - chemical and moisture resistant - outdoor stability






20. Low- molecular- weight building blocks repeated in the polymer chain






21. On of the two most common reaction schemes used to create polymers - involving three steps: initiaition - propogation - and termination






22. Technique used to make rayon - which involves treating cellulose from wood or cotton with alkali and extruding it through a spinneret






23. Formation of side chains along the backbone; presence of branches disrupts the interactions beween adjacent chains; lowering the tensile strength - melting point - stiffness - crystallinity - and density






24. Specified weight of a polymer that is injected into the mold at the end of the barrel during the injection molding process






25. Arrangement of the largest substituents where the substituets are offset by 120






26. Type of polyamide in which less that 85% of the amide groups are bonded to the aromatic rings






27. Polymer that is made up a single repeat unit






28. Term associate with blown - film apparatus - which indicated the point at which the molecules develop a more crystalline orientation around the bubble of air






29. Plexiglas - lucite - transparent - shatterproof - biocompatible - hockey rinks - taillights - implants






30. Part of the extrusion apparatus that contains a heated screw which is used to melt the polymer and the polymer forward into the next chamber






31. Second- order thermodynamic transition in which the onset of large scale chain mobility occures in polymers. Bellow Tg the polymer is glasslike and brittle. above Tg the polymer becomes rubbery and flexible






32. Additives whose primary purpose is to reduce the final cost of the product






33. Orlon - acrilan - lightweight - durable - carbon - fiber precursor - tennis - racing bikes - helmets






34. Last step in the polymerization process - which occurs when the free radical of a polymer chain joins the free radical on an end group






35. Is not asymetric and cannot have multiple configurations






36. Relative configuration of adjecent asymmetric carbons






37. Polymers comprised of two or more different monomers - which attach to the polymer chain in no particular order of pattern






38. Term used to represent the average molecular weight of a sample containing a wide range of polymer chain lengths. this term is used to avoid confusion between the number average and the weight molecular average weight






39. Lightwieght polymer that absorbs water well; the first syntheric polymer ever constructed






40. One type of polymer that contains at least 85% of polyacrylonitrile PAN






41. Large spool that is used to wind solidified polymer fibers after they have been pushed through the spinneret






42. Number of bonds a molecule has formed






43. Coloring agent that is dissolved directly into the polymer - causing the polymer to change color






44. Polymers that contain amide (- N-) groups in the chain






45. Simple polymeric material produced as pellets in large quantities






46. Broad category of polymers that includes polymers containing urethane linkages






47. Covalent bonding of the polymer backbone and side groups






48. Molecule containing a highly reactive unpaired electron






49. Additives that improve a polymer's resistance to variable that cause bonds to rupture - such as heat and light






50. An acid and an alcohol