Page 721 - Carrahers_Polymer_Chemistry,_Eighth_Edition

684 Carraher’s Polymer Chemistry

24. Both sun tan lotion and additives added to plastics form a similar role and act to protect in a
similar fashion so it is not unexpected that the additives are often the same or similar.
25. Additives are added to enhance or modify a particular property. Such there are so many poly-
mers used in such a variety of ways there are many properties that need to be modifi ed. Thus,
there are many materials that are used to help achieve the desired outcome.

CHAPTER 16

+3
+2
1. So-called polyvalent ions; that is cations with more than a univalent charge such as Ca and Fe .
2. Cross-linking through the double bond.
3. –(–CD –CD –)–
2 2
4. Time. Also, yield will be generally lower for PS.
5. When unzipping is not likely to occur. For most polymers.
6. Expose it to high-energy radiation.
7. Hydrogenate the block copolymer of styrene and isoprene.
8. They are both alternating copolymers of propylene and ethylene.
9. It controls the approach of oxygen and other molecules by size and electronic character.
10. No. It is below the entanglement length.
11. Size, shape, and electronic nature.
12. Succinic aldehyde.
13. PVA and PAA.
14. The introduction of a few methoxyl groups reduces the hydrogen bonding forces so that the
polymer with the remaining hydroxyl groups will dissolve in water.
15. It forms a protective film around dirt particles and prevents their redeposition.

16. No. Both steric and accessibly prevent 100% reaction.
17. The maximum, that is, about 2.8.
18. All of the hydroxyl groups are inaccessible in the hetergeneous acetylation reaction.
19. (b) has more free hydroxyl groups.
20. There are residual acetyl groups in the reactant PVA, and the acetal formation requires two
1,3-hydroxyl groups. Also, on a statistical basis some of the –OH groups become isolated.
21. Can use a fatty acid and employ esterifi cation.
22. Formation of carbon dioxide and water.
23. None. Any vinyl alcohol would rearrange to acetaldehyde.
24. (a) Polystyrene
25. (a) Cations
26. Helps remove fat and other unwanted materials leaving a protein-rich material that will last
longer.
27. (c), (d), (e), and (f).
28. Heat polymer and condense the monomer produced by thermal depolymerization.
29. It readily forms hydrogen chloride and aromatic fused ring systems.
30. Material is material. Responses are structure and geometrical driven whether the material is
biological or synthetic. Often, synthetic chemists would like materials that had similar behavior
to biomolecules, so they look to see what the key structural features are to give the particular
biomolecule response and attempt to make use of these findings to achieve the desired outcome

except with synthetic materials. Scientists dealing with most biomolecules are also polymer
scientists, applying their efforts on biomaterial.
31. A better term is “protected” since part of the structure is present to hold the iron in an active
geometry, while much of the remaining structure protects the active iron site from unwanted
intruders that can damage its natural action.

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