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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. 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






2. 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






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






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






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






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






7. 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






8. Double bounded organic molecule used to begin addition polymerization






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






10. An acid and an alcohol






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. Number of bonds a molecule has formed






13. Specific arrangements of atoms that cause organic compounds to behave in predictable ways






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






15. 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






16. 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






17. Softening agents






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






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






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






21. Atoms attached to the polymer backbone.






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






23. Polymer that is made up a single repeat unit






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






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






26. Molecule containing a highly reactive unpaired electron






27. Covalent bonding of the polymer backbone and side groups






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






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






30. Porcess of breaking large organic hydrocarbons into smaller molecules






31. 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






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






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






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






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






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






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






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






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






40. 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






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






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






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






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






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






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






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






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






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






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