Shun-Myung Shin*, Toshiaki Yoshioka** and Akitsugu Okuwaki**

* Core Research for Evolutional and Technology, JST
** Department of Applied Chemistry, Graduate School of Engineering, Tohoku University

+ Correspondence should be addressed to Toshiaki Yoshioka:
(Aoba, Aramaki-Aza, Aoba-ku, Sendai, 980-8579 Japan)

Abstract

Agricultural PVC film containing PVC 64.5%, DOP (dioctylphthalate) 32% as a plasticizer, Ca-Zn stearatesandsurfaceactiveagentwastreatedin0-7MNaOHsolutionsat150-250*C[Celsius degeree]for0-12h, in order to study the behavior of degradation and characteristics of produced char. The degree of weight loss due to the decomposition reached 31% for the reaction in 3M NaOH over 225*C[Celsius degeree] for 0h, which corresponded to the loss of all the plasticizer contained in the agricultural PVC film. Under the same conditions, DOP was hydrolyzed quantitatively to phthalic acid and isooctyl alcohol by the alkali catalyst. In the hydrothermal reaction, the pores in size 10-12[micro]m were produced in the film by the hydrolysis of DOP, besides the succeeding parallel dehydrochlorination of PVC produced smaller pores and brought about the shrinkage of film. The pore size became smaller, about 1-8[micro]m for 12h, along with time.

Key words: agricultural PVC film, hydrothermal reaction, DOP, phthalic acid, char