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Title: Model investigation of the effect of plasticizer on radiation stability of poly(vinyl chloride). [Gamma radiation]

Journal Article · · J. Polym. Sci., Polym. Lett. Ed.; (United States)

The aim of this investigation was to determine the changes that occur due to a plasticizer in an analytically determinable radiolysis product of a model compound. For comparison two model compounds were used, 4-chlorohexene-1 and 4-chlorohexene-2. By using gas chromatography and uv absorption spectroscopy, it was established that the radiolysis products of 4-chlorohexene-1 are quite unstable. Therefore this compound could not be used as a suitable model, and only 4-chlorohexene-2 was used as the model. The highlight of this study was the determination of hexadiene-2,4 produced in the process of the radiolysis according to: CH/sub 3/-CH==CH-CHCl-C/sub 2/H/sub 5/ ..-->.. CH/sub 3/CH==CH-CH==CH-CH/sub 3/ + HCl and also the investigation of how the process is affected by the plasticizer, dibutyl sebacate (DBS). It was established that in mixtures of the same proportions of DBS and 4-chlorohexene-2 the degree of unsaturation is less in an irradiated system than in an unirradiated one, but the differences are small. The following interpretations are possible: (a) the decrease of the unsaturation degree is due to reactions of 4-chlorohexene-2 and hexadiene-2,4 with DBS; (b) as a result of the radiolysis of dibutyl sebacate, butene and sebacic acid are produced. The sebacic acid links easily to 4-chlorohexene-2 and butene increases the number of double bonds. In conclusion, the decrease in the number of double bonds in the system results from the influence of ester, or to a lesser extent, of acid formed from this ester. However, whether the reaction with the model compound or with its decomposition product is dominant is not essential for the explanation of the influence of the plasticizer on the PVC. The decrease in number of double body in the model compound corresponds to a removal of polyene sequences in PVC by the plasticizer.

Research Organization:
Nicholas Copernicus Univ., Torun, Poland
OSTI ID:
6698689
Journal Information:
J. Polym. Sci., Polym. Lett. Ed.; (United States), Vol. 18:12
Country of Publication:
United States
Language:
English