ISSN:
0022-3832
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The discovery has been made that when vinyl chloride is polymerized in certain aldehydes, a highly crystalline polyvinyl chloride is obtained. In butyraldehyde, low yields of a range of low molecular weight polymers are produced. Elemental analyses showed that they may be characterized by the formula: where n = 6-26. Support for this structure and molecular weight range was obtained from infrared and x-ray examinations of the polymers. The polymers are highly crystalline, as demonstrated by the x-ray and infrared results, and appear to have a syndiotactic structure. Variation of the polymerization temperature produced no measurable effect on the polymer stereoregularity. The ability of substituted aliphatic aldehydes to produce stereoregular PVC has shown a dependence on the electronegativity of the substituent in the aldehyde. Aliphatic aldehydes with an electron-releasing α-methyl group appear to give a more highly crystalline PVC. Aliphatic aldehydes with electron-withdrawing chlorine and oxygen atoms gives less crystalline PVC than do the corresponding α-methyl aldehydes. The dependence of the results upon polar effects suggests that the stereoregulating mechanism of the aldehydes involves association between the aldehyde, as a donor molecule, and the free propagating species, as the acceptor radical.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1961.1205415903
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