Tannic acid functionalized UV-curable carbon nanotube: Effective reinforcement of acrylated epoxidized soybean oil coating

In this study, an efficient method of preparing tannic acid functionalized UV-curable carbon nanotube for the reinforcement of acrylated epoxidized soybean oil coating is presented. A photoactive tannic acid (pTA) was prepared by the ring opening reaction of tannic acid (TA) and glycidyl methacrylate (GMA), and then used to non-covalently functionalize carbon nanotubes via π-π interactions to obtain a novel kind of tannic acid functionalized UV-curable carbon nanotube (pTA/MWCNTs). The pTA/MWCNTs was fully characterized and subsequently incorporated into acrylated epoxidized soybean oil (AESO) covalently via UV curing technology. A series of epoxidized soybean oil acrylate composite with different content of pTA/MWCNTs were prepared and the properties of pTA/MWCNTs/AESO composite materials were investigated. Real-time IR and ATR-FTIR were used to monitor the double bond conversion and deep curing of pTA/MWCNTs/AESO coating. The mechanical properties of UV-cured films were evaluated by tensile testing. The results showed that the introduction of pTA/MWCNTs effectively enhanced the physical and mechanical properties of AESO. And when the loading of pTA/MWCNTs is 0.8 wt%, optimal reinforcing effect for AESO matrix was observed with the tensile strength and modulus of the pTA/MWCNTs/AESO composite improved by 109% and 409%, respectively. In great contrast, the introduction of pristine MWCNTs without modification leads to the incomplete curing of AESO and thus a great decrease in the mechanical performance, demonstrating the important role of modification by pTA.