Natural rubber grafted poly(methyl methacrylate) as compatibilizer in 50/50 natural rubber/nitrile rubber blend

Abstract

The effects of graft copolymers applied as compatibilizers for natural rubber/nitrile rubber (NR/NBR) blends at 50/50 (w/w) on cure characteristics, mechanical properties, thermal properties, oil resistance, and morphology were investigated. The graft copolymers of methyl methacrylate (MMA) onto NR initiated by benzoyl peroxide (NR- g-PMMA<BPO>) and by potassium persulfate (NR- g-PMMA<PPS>) under emulsion polymerization were synthesized and used to compatibilize the blends. The structures of the copolymers were characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. NR was blended with NBR via a two-roll mill at 70°C under the compatibilizer loading ranging from 0 to 10 parts per hundred of rubber (phr). The results showed that the tensile property and tear strength of the blends increased with the increasing amount of NR- g-PMMA<BPO> as a compatibilizer. Thermal aging determined in terms of tensile properties exhibited the smaller difference between before and after aging in an oven with the increasing compatibilizer loading. The morphology of the compatibilized NR/NBR vulcanizates was investigated by scanning electron microscopy of the tensile fracture surfaces, which exhibited the improvement of interfacial adhesion between the two rubber phases. The thermal properties of compatibilized NR/NBR vulcanizates were reported in terms of a glass transition temperature under differential scanning calorimetry and dynamic mechanical analysis. The incorporation of an appropriate amount of the compatibilizer into the blends apparently improved the oil resistance of NR. Among them, the blend filled with 7.5 phr of NR- g-PMMA<BPO> showed the lowest volume change in IRM 903 oil.

Properties of Emulsion Paint with Modified Natural Rubber Latex/Polyvinyl Acetate Blend Binder

“…However, the relative monomer content variation did not produce a significant difference in the degree of grafting. As has been reported in previous studies, the highest grafting rate in the molecular rubber chain was at monomer content 60:40-80:20 [19,20]. The decreased washability resistance due to the increase in the LNR-g-(MMA-co-St) level in PVAc can be caused by the viscosity and water content.…”

Experimental and Modelling Study of the Effect of Adding Starch-Modified Natural Rubber Hybrid to the Vulcanization of Sorghum Fibers-Filled Natural Rubber

“…This agent is synthesized by chemically modifying the main structure of NR to create a new NR structure that consists of polar and nonpolar parts. In previous works, modifying the chemical structure of NR was performed through grafting a synthetic polar compound such as maleic anhydride [ 14 ], methyl methacrylate [ 15 ], acrylonitrile [ 16 ], and styrene [ 17 ] onto the backbone of the rubber [ 18 ]. In this study, we used a coupling agent that was synthesized through grafting biomass, i.e., starch to NR backbone producing hybrid material [ 19 ].…”

Kemampuan Proses Dan Karakteristik Vulkanisasi Campuran NBR/Epdm

“…MBS mengandung polimer karet pada susunan elastomernya yaitu styrene-butadiene rubber (SBR) sehingga dapat meningkatkan sifat mekanik polimer (Ren et al, 2014;Liu et al, 2014;Zhou et al, 2012). MBS juga banyak digunakan sebagai kompatibiliser baik untuk plastik (Moolsin & Saksayamkul, 2016;Mousavi & Amraei, 2015;Liu et al, 2014). Montmorillonite (MMT) adalah salah satu mineral tanah liat alami yang memiliki luas permukaan yang besar.…”