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






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






3. Form of the molecular weight of a sample of polymer chains determined by dividing the mass of the specimen by total number of mols present; always less than weight average molecular weight; all molecules regardless of size correlate well with Mn






4. Simple polymeric material produced as pellets in large quantities






5. Polymers that cannot be repeatedly melted and re- formed due to strong covalent bonding between chains






6. One of the two different types of termination in the polymerization process. during this type of termination - the free radicals from two different polymer chains join to end the propogation process






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






8. Polymer in which more than 85% of the amide groups are bonded to two aromatic rings






9. Is not asymetric and cannot have multiple configurations






10. Softening agents






11. Molecule containing a highly reactive unpaired electron






12. Long chain polymers that contain at least 85% of an ester of a substituted aromatic carboxylic acid. these fibers are strong and can dyed or made transpared






13. Number of bonds a molecule has formed






14. Term used to describe a polymer that contains significant numbers of both syndiotactic and isotactic dyads






15. First step in the process of polymerization - during which a free radical is formed






16. Sylon - transparent - shatter proof - biocompatible - hockey rinks - taillights - implants






17. Second stage of polymerization process during which the polymer chain begins to go as monomers are added to the chain






18. Process used to make thermoset fibers by performing the polymerization reacting in a solbent as the material flows through a spinneret and into a quenching bath






19. Polymers comprised of two or more different monomer units that attach to the chain in an alternating pattern A-B-A-B...






20. 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






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






22. Polymers comprised of two or more different monomers that attach to the chain in long runs of one type of monomer - followed by another monomer AAAAAAAAAAAAABBBBBBBBBBBBBBBBBBAAAAAAAA






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






24. Additives that cause swelling - which allows the polymer chains to slide past one another more easily - making the polymer softer and more pliable. also used to decrease the viscosity of cement paste to make it easier to flow






25. 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






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






27. Process of pushing polymers through a spinneret and winding the solidified fibers onto a tow - which imposes a shear stress on the fibers upstream as they emerge from the spinneret






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






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






30. Covalently bonded chains of molecules with small monomer units repeated from end to end






31. Molecules added to a polymer to enhance or alter specific properties or molecules added to concrete for purposed other than altering a specific property






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






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






34. Polymer that is made up a single repeat unit






35. An acid and an alcohol






36. Relative configuration of adjecent asymmetric carbons






37. Covalent bonding of the polymer backbone and side groups






38. Smallest repeating unit in a polymer. aka repeat unit






39. Carbon atom capable of multiple configurations due to four different substituents






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






41. Pigments or dyes that change the way light is absorbed or reflected by a polymer






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






43. Refers to the spatial geometry of the main chain carbon and substituents that can be changed by rotation and flexural motion






44. Polymers in which one chain of a particular monomer is attached as a side to a chain of another chain of monomer






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






46. Covalently bonded atoms which are usualy carbon - that comprise the center of the polymer chain.






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






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






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






50. One method of expressing the molecular weight of sample of polymers with averaging based on weight; this method is more useful when large molecules in the sample dominate the behavior