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






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






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






4. Molecule containing a highly reactive unpaired electron






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






6. 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






7. 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






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






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






10. Atoms attached to the polymer backbone.






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






12. 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






13. 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






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






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






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






17. 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






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






19. Coloring agents that do not dissolve into the polymer






20. Smallest repeating unit in a polymer. aka repeat unit






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






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






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






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






25. Polymer that is made up a single repeat unit






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






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






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






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






30. 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






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






32. Is not asymetric and cannot have multiple configurations






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






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






35. 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






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






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






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






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






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






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






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






43. 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






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






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






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






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






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






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






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