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






2. Small chains of bonded monomers whose properties would be altered by the addition of one more monomer unit






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






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






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






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






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






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






9. Configuration of a substituent in a polymer - in which the substituent is located on the same side of the polymer chain in all repeating units






10. Number of bonds a molecule has formed






11. 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






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






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






14. 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






15. Molecule containing a highly reactive unpaired electron






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






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






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






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






20. 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






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






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






23. 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






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






25. 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






26. Coloring agents that do not dissolve into the polymer






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






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






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






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






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






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






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






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






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






36. 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






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






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






39. 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






40. Softening agents






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






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






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






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






45. 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






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






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






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






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






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