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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. Porcess of breaking large organic hydrocarbons into smaller molecules






3. 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






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






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






6. Number of bonds a molecule has formed






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






8. Is not asymetric and cannot have multiple configurations






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






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






11. Covalent bonding of the polymer backbone and side groups






12. Primary raw material for most polymers






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






14. 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






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






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






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






18. Relative configuration of adjecent asymmetric carbons






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






20. Spatial arrangement of substituents around the main chain carbon atom that can be altered only by the breaking of bonds






21. 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






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






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






24. 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






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






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






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






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






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






30. 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






31. 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






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






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






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






36. Softening agents






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






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






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






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






41. 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






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






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






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






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






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






47. Molecule containing a highly reactive unpaired electron






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






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






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