Compatibility study in natural rubber and maize starch blends

Blends containing various ratios of natural rubber (NR) and maize starch (MS) were prepared on a two roll mill. The effect of starch contents on physico-mechanical properties and curing characteristics of the prepared blend vulcanizates was investigated. The data indicate poor mechanical properties, delayed cure rate index, and decreased maximum torque with increasing starch content in the blend formulation. This indicates that the interfacial interaction between the blend components was poor. Various contents of the compatibilizers, maleic acid anhydride (MAH) and glycidyl methacrylate (GMA), were mixed with the blend NR/MS (90/10). The effect of the compatibilizer contents on the physico-mechanical properties and curing characteristics of the binary blend was investigated. Compatibilized blends with GMA (1 phr) showed an improvement in the physico-mechanical properties in comparison with uncompatibilized blend samples. Blends with MAH exhibited higher modulus and hardness values with respect to GMA blends. The efficiency of the compatibilizers was also evaluated by studies of phase morphology (scanning electron microscope), Fourier transform infrared spectroscopy, and thermal stability (thermogravimetric analysis). (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012