Nova metodologia para a preparação de termoplástico vulcanizado a base de borracha nitrílica carboxilada e poli(metacrilato de metila) (XNBR/PMMA)

Abstract

This work proposed the development of a new methodology for preparation of carboxylated nitrilic rubber and poly(methyl methacrylate) (XNBR / PMMA) blends. This methodology consisted in the polymerization of methyl methacrylate monomer (MMA) inside the XNBR rubber. First, the monomer was incorporated into XNBR particles and the benzoyl peroxide was used as initiator for this polymerization. The XNBR/PMMA blends were characterized by infrared spectroscopy (FTIR) and Proton Nuclear Magnetic Resonance (1H NMR). The results indicated the presence of both polymers in the blends. Thermogravimetric analysis (TGA) indicated the presence of 10% of PMMA in the blends. The effect of reaction time on rheological properties was evaluated by RPA. For blends obtained with 1h, 5h and 9h an increased of molecular weight of PMMA was observed, due to the decrease of viscous modulus. The scanning electron microscopy (SEM) of theses samples revealed the presence of PMMA in the elastomeric phase, indicating the efficiency of in situ polymerization. The morphology of the blends revealed the presence of microdomains, indicating the microheterogeneity of the mixture.