Phenomenological study of the transfers between a plasticizer dispersed in a plastic disc and sunflower oil

✍ Scribed by A.E.H. Gheid; N. Fertikh; A. Mansour; D. Messadi

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 442 KB
• Volume: 26
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(90)90042-3

✦ Synopsis

When plasticized PVC discs are immersed in sunflower oil, simultaneous diffusion of the plasticizer (dioctyl phthalate; DOP) out of, and the vegetable oil into, the discs may occur. The use of labelled DOP and radioactivity measurements in conjunction with weight loss give quantitative information on the mass exchanged and lead to the profiles of the DOP concentration developed through the polymer matrix during the process. The kinetics of the transfer were studied by considering Fickian diffusion in a non-steady state for the plasticizer. This treatment led to evaluation of two types of diffusion coefficient viz. an average coefficient (D) and local ceofficients (/~). The following factors affecting the migration process were examined: the amount of plasticizer (20-50%), temperature (20-50°C), time, relative volume and stirring of sunflower oil. The rate of DOP transfer into sunflower oil was found to depend on temperature. The activation energy was 45.6 kJ/mol over the temperature range considered.