Grafting copolymerization of maleic anhydride onto styrene‐butadiene‐styrene block copolymer through solvothermal process

The grafting copolymerization of maleic anhydride (MAH) onto styrene‐butadiene‐styrene terpolymer (SBS) was carried out through a new synthesis method––solvothermal synthesis. Infrared (IR) spectra and solid state 13C‐NMR confirmed that maleic anhydride was successfully grafted onto the SBS backbone. The effects of different solvents, different initiators and their concentration, the amount of MAH, SBS concentration, and reaction time on the graft degree were evaluated, and the optimal conditions were obtained. Results indicated that the grafting reaction of MAH onto SBS through solvothermal method can be carried out in both good solvents and poor solvents, which are much different from the traditional solution grafting method, and high grafting degree can be obtained in good solvents. Finally, we also compared the grafting degree (GD) prepared by the solvothermal method with that by the melt grafting method and solution grafting method.