Effects of silane hydrolysis time on the physicochemical properties of bioplastics based on starch and epoxidized soybean oil

This work investigated the effects of 3-aminopropyl triethoxy silane (APTES) hydrolysis time on the physicochemical properties of the resulting starch/epoxidized soybean oil (ESO) bioplastics comprehensively. FTIR analysis confirmed that APTES hydrolyzed for 4 h had the best modification effect on starch. The results of XRD and TGA demonstrated the successful silylation of starch by APTES despite hydrolysis time. Silylation treatment reduced the thermal stability of starch slightly, but enhanced the thermal stability of the resultant bioplastics, revealing better interaction between silylated starch and ESO. The interfacial adhesion of starch and ESO in the bioplastics was obviously enhanced when APTES was hydrolyzed for 2-24 h. The bioplastics with APTES hydrolyzed for 2-4 h showed more desirable tensile properties as the silane hydrolysis was complete and self-condensation of hydrolyzed silanes was avoided. The bioplastics containing silylated starch still showed superior opacity and biodegradability.