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






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






3. 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






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






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






6. 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






7. Relative configuration of adjecent asymmetric carbons






8. 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






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






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






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






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






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






14. Porcess of breaking large organic hydrocarbons into smaller molecules






15. 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






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






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






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






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






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






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






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






24. Covalent bonding of the polymer backbone and side groups






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






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






27. 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






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






29. Polymer that is made up a single repeat unit






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






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






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






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






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






35. Primary raw material for most polymers






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






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






38. 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






39. Softening agents






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






42. 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






43. 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






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






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






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. 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






49. An acid and an alcohol






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