ISSN:
0449-2951
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The radiation-induced polymerization of n-perfluoropentadiene-1,4 was studied at temperatures of 100-170°C. and pressures of 8,000-15,000 atm. Kinetic evidence indicates that polymerization occurs by a free radical reaction; the activation energy is between 14 and 17 kcal./mole and the activation entropy is -8 ± 5 e.u./mole. Transfer with monomer limits the number-average degree of polymerization to values of 40 or less except in special circumstances. Dimerization and double bond migration occur to some extent; n-perfluoropentadiene-1,3 is formed in the latter process. It and the 1,4-diene copolymerize; the latter undergoes cyclic addition so that the polymers are soluble and have little perfluorovinyl unsaturation. The polymers are brittle if the fraction of 1,3-diene in the polymer is less than 0.1. They are rubbery and of considerably higher molecular weight if the fraction of 1,3-diene is greater than 0.4. The thermal stability of the polymers decreases as the content of 1,3-diene increases.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1965.100030431
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