Insights into self-healing performance of epoxidized deproteinized natural rubber/graphene oxide composite

The self-healing performance of epoxidized deproteinized natural rubber (EDPNR) and EDPNR/graphene oxide (GO) composites was investigated. Composites of EDPNR25 and EDPNR50 with GO contents of 0.5 and 1.0 phr were prepared by adding a GO dispersion into a EDPNR latex and the product was subsequently cast into films. Tensile strengths of the original samples and after self-healing were used to evaluate self-healing performance. The tensile strength of EDPNR25 after self-healing achieved about 65% of tensile strength of original EDPNR25. The recovery of tensile strength for the composite increased to 81% for EDPNR25/GO0.5 and 105% for EDPNR25/GO1.0 for self-healing at 25[degrees]C for 24 h. At 70[degrees]C, EDPNR25/GO0.5 and EDPNR25/GO1.0 composite achieved ~100% recovery after 24 h. On the other hand, the tensile strength recoveries of EDPNR50, EDPNR50/GO0.5, and EDPNR50/GO1.0 were relatively low (33%, 28%, and 24%, respectively) at 25[degrees]C. At 70[degrees]C, recoveries increased to 63%, 67%, and 52%, respectively. This result demonstrated that the interdiffusion of epoxidized natural rubber molecules plays a key role in the self-healing performance rather than hydrogen bonds between GO and functional groups on EDPNR molecules. KEYWORDS epoxidized deproteinized natural rubber, graphene oxide, hydrogen bonds, interdiffusion, self-healing
1 | INTRODUCTION In recent years, humans have been facing environmental problems of discharging thermoset plastics and vulcanized natural rubber (VNR) products since these materials are difficult to be recycled [...]