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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. 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






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






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






4. 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






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






6. Is not asymetric and cannot have multiple configurations






7. An acid and an alcohol






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






9. Polymer that is made up a single repeat unit






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






11. 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






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






13. Device used in the processing of polymers that melts polymer pellets and feeds them continuously through a shaping device






14. Formation of a plymer that occurs when two potentially reactive end groups on a polymer react to form a new covalent bond between the polymer chains. this reaction also forms a biproduct - usually water






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






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






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






18. 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






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






20. Circular - stationary block with small holes through which molten polymer can flow to take the shape of a fiber






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






22. 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






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






24. Peice of the extrusion apparatus that is used as a filter to separate unmelted particles - dirt - and other solid contaminants from the molten polymer






25. Molecule containing a highly reactive unpaired electron






26. Coloring agents that do not dissolve into the polymer






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






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






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






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






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






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






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






34. 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






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






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






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






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






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






40. High distance- dependent bonding between adjacent polymer chains; usually includes hydrogen bonding - dipoles - and van der waals






41. Covalent bonding of the polymer backbone and side groups






42. Two or more polymers mechanically mixed together but without covalent bonding between them






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






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






45. Type of plymer processing similar to extrusion but can be used to develop parts with complex shapes rapidly






46. Primary raw material for most polymers






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






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






49. Number of bonds a molecule has formed






50. 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