Soil Burial Degradation of New Bio-Based Additive Plasticized Poly (Vinyl Chloride) Films and the Biodegradation of Di Octyl Phthalate and di isononyl adipate plasticizers*

摘要

In the first step of this work, Commercial sunflower oil was epoxidized, and epoxidized sunflower oil (ESO) was used as a thermal stabilizer for poly (vinyl chloride) (PVC). Plasticized formulations stabilized with ESO as a new biodegradable stabilizer and epoxidized soya bean oil (ESBO) as a commercial stabiliser for comparison were realized. Two plasticizers were used: dioctyl phthalate (DOP) and diisononyl adipate (DINA). The aging of the PVC samples was investigated in a landfill soil for 24 months. The mass samples variations were followed as a function of soil burial time. Furthermore, the evolution of density and mechanical properties (tensile and shore D hardness) was investigated. The results showed that the nature of the plasticizer and heat stabilizer affects the properties of PVC as well as the phenomena of migration and biodegradation.The aim of the second part of the present study is to compare the biodegradation of di octyl phthalate (DOP) and di isononyl adipate (DINA). The biodegradation of DOP and DINA by Pseudomonas aeruginosa was investigated after the validation and application of a simple respirometer system designed to assess mineralization of plasticizers under defined conditions. The soil used was collected near a landfill. The results revealed that biodegradation of the two plasticizers by P. aeruginosa occurred and thatDINA is more biodegradable than DOP. The respirometer test demonstrated that after the thirty-ninth day of incubation, the rate of biodegradation of DOP is equal to 38%, while the mineralization rate of DINA is equal to 62%.