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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. 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






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






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






4. 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






5. 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






6. Atoms attached to the polymer backbone.






7. Double bounded organic molecule used to begin addition polymerization






8. An acid and an alcohol






9. Is not asymetric and cannot have multiple configurations






10. 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






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






12. Covalent bonding of the polymer backbone and side groups






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






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






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






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






17. 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






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






19. 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






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






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






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






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






24. Number of bonds a molecule has formed






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






26. 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






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






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






29. Configuration of a polymer in which the sucstituent is located on opposite sides of the molecule in each repeating unit






30. Relative configuration of adjecent asymmetric carbons






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






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






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






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






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






36. Molecule containing a highly reactive unpaired electron






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






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






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






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






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






42. Softening agents






43. Number of repeat/structural units in a polymer chain






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






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






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






47. 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






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






49. Simple polymeric material produced as pellets in large quantities






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