ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
At present various polymerization reactions are known which yield approximately identical types of eutactic polymers. This has been confirmed experimentally for a sufficient number of monomers (α-olefins, conjugated diolefins, vinyl esters, alkylene oxides, etc.) to lead to the conclusion that stereoregularity is based on a single or a few general acts. The mechanisms proposed for the formation of stereoregular polymers, i.e., radical, through alkyltitanium compounds (Nenitescu), semiconductor surface (Topchiev), or ionic (Natta, Furukawa), do not give a sufficiently general solution to the problem. Whereas some authors do not take into account the ionic character of some types of polymerization reactions and the possibility of free rotation of the macroradical around the C—C axis, others neglect the fact that radical reactions are known which leading to the formation of stereoregular units. Particularly useful is a generalization of the remarks concerning the steric control of unsymmetric induction (Cram). Stereospecific polymerization, or, to be more exact, the act or elementary acts leading to stereo-regularity of the molecules formed, should proceed just in the same manner as other stereospecific reactions. The authors of the present report attempted to find common elements between the different reaction mechanism leading to the formation of eutactic polymers.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1961.1205215706
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