Radiochemical ageing of poly(vinyl chloride) plasticized by didecylphthalate

✍ Scribed by F. Thominette; G. Metzger; B. Dalle; J. Verdu

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 357 KB
• Volume: 27
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(91)90125-8

✦ Synopsis

Samples of PVC containing 15, 20, 25 or 30% by weight of didecylphthalate (DDP) were exposed to ~ radiation, at ambient temperature in air. DDP seems to reduce the radiochemical yield of crosslinking, G(X), and to increase the radiochemical yield for chain seission, G(S). Investigations on thin layers in the surface and in the interior of the samples reveal, however, that the oxidative chain seission is diffusion controlled, the oxygen diffusivity being an increasing function of the plasticizer concentration. Thus, G(S) increases with the volume fraction of the oxidized layer whose depth increases with the plasticizer concentration, whereas G(X) remains almost constant in the interior. A process of DDP dimerization was indicated by steric exclusion chromatography coupled with u.v. spectrophotometry.