Grafting of Itaconic Anhydride onto Natural Rubber as Compatibilizer for Rubber Blend, Experimental Optimization of Grafting Extent

摘要

Graft copolymers of natural rubber with itaconic anhydride (IA) were prepared in toluene using benzoyl peroxide (BPO) as an initiator. The effects of reaction temperature, reaction time, monomer concentration and initiator concentration on natural rubber grafting were investigated. Graft copolymers (NR-g-IA) were characterized by Fourier transform infrared spectroscopy (FTIR). The grafting content of IA onto NR was estimated by means of FTIR using the absorbance peak ratio for 1783 cm~(-1) and 835 cm~(-1), corresponding to the symmetric C=O stretching and the =C-H out of plane bending in natural rubber, respectively. Titration was also used to determine the amount of IA grafted onto natural rubber. The optimal grafting conditions for preparation of NR-g-IA were found at 10 phr IA, 2.5 phr BPO, 85°C temperature, and 2.5 hr reaction time.