Studies of latex blends of natural rubber/poly(methyl methacrylate-co-2-ethylhexyl methacrylate) and their comparison with incompatible natural rubber/poly(methyl methacrylate)

Abstract

Poly(methyl methacrylate-co-2-ethylhexyl methacrylate) copolymers with 0.6–49.2 mol% of 2-ethylhexyl methacrylate were synthesized and blended with natural rubber at three different blend ratios (i.e. 5/95, 10/90, 15/85) on the latex stage. Chemical structure of the copolymer was confirmed by FTIR and 1H NMR spectroscopy. Mechanical strength of the blend (rubber/copolymer) containing 7.76 mol% of 2-ethylhexyl methacrylate showed the higher values than the incompatible blend natural rubber/PMMA. According to water absorption and ATR-FTIR measurements, the amount of dispersed particles of obtained blends on the surface decreases sharply compared to rubber/PMMA blend. Scanning electron microscopy and atomic force microscopy also showed that surface and cross-section morphologies of the studied were more homogeneous than those of incompatible blend. The miscibility of studied blend was further reflected by DSC analysis.