Synthesis of Bio-base Plasticizer Using Waste Cooking Oil and Its Performance Testing in Soft Poly(vinyl chloride)Films

Waste cooking oil was modified to prepare bio-base plasticizers(a,b and c)with terephthalic acid,adipic acid and benzoic acid by transesterification,epoxidation and ring opening reactions,respectively.The polyvinyl chloride(PVC)films(a/PVC,b/PVC and c/PVC)were prepared using a,b and c as bio-base plasticizers.The epoxidation and ring opening reactions were mainly investigated through GC-MS analysis.The structures of bio-base plasticizers(a,b and c)were confirmed by Fourier transform infrared spectroscopy(FT-IR),^(1)H NMR and ^(13)C NMR.The mechanical properties of a/PVC were as good as those of PVC films with the dioctyl phthalate(DOP)plasticizer.Meanwhile,the elongation at break of c/PVC reached 422%.The glass transition temperature(Tg)from dynamic mechanical analysis(DMA)was reduced to 30.6℃,45.3℃,23.6℃and 40.6℃,respectively when 40 phr of a,b,c and DOP plasticizer were added.Results of thermogravimetric analysis(TGA)illustrated that the thermal degradation stabilitiy of a/PVC films was better than those of c/PVC and DOP/PVC.The volatility losses of a,b and c were lower than that of the DOP.Bio-base plasticizers a and c exhibited excellent migration resistance in different solutions(distilled water,50%ethanol(w/w)).The FT-IR of PVC films showed that the downfield shifts of the—CH—Cl groups of the PVC plasticized with a and c were greater than that of b/PVC.The bio-base plasticizers b had a better plasticizing effect at low temperature.