Investigation of cure and mechanical properties of graft copolymer of deproteinized natural rubber (DPNR) with methyl methacrylate (MMA) prepared by graft copolymerization in latex was presented in this work. It is determined that the increase in scorch time, cure time, hardness and tear strength of the graft copolymer were depended on monomer concentration | Vietnam Journal of Chemistry, International Edition, 54(4): 520-523, 2016 DOI: Investigation of cure and mechanical properties of deproteinized natural rubber-g-poly methyl methacrylate Nguyen Thi Nhan, Tran Anh Dung, Pham Duy Khanh, Nghiem Thi Thuong, Nguyen Huy Tung, Phan Trung Nghia, Tran Thi Thuy* Hanoi University of Science and Technology Received 21 June 2016; Accepted for publication 12 August 2016 Abstract Investigation of cure and mechanical properties of graft copolymer of deproteinized natural rubber (DPNR) with methyl methacrylate (MMA) prepared by graft copolymerization in latex was presented in this work. It is determined that the increase in scorch time, cure time, hardness and tear strength of the graft copolymer were depended on monomer concentration. With the monomer concentration of 15 g/100 g rubber, the increase of hardness and tear strength are 68 % and 66 %, respectively, compared to DPNR. Besides, there are increasing trends of tensile strength and elongation at break. The optimum concentration of MMA monomer is found at 15 g/100 g-rubber. At this monomer concentration, the hardness and tear strength of the graft copolymer increased, whereas the elongation at break and the tensile strength decreased a bit compared to the natural rubber. Keywords. Natural rubber, polymethyl methacrylate, grafted copolymer, curing properties, mechanical properties 1. INTRODUCTION containing 60 % dried rubber content (DRC), Merufa company (Vietnam). Sodium dodecyl sulfate (SDS) and urea, Nacalai Tesque (Japan). MMA, TEPA and TBHPO, Sigma Aldrich. Natural rubber (NR) is composed of 93-95 % cis-1,4-polyisoprene. It is an unsaturated elastomer having excellent properties, such as high strength, outstanding resilience and high elongation at break [1]. However, NR is very sensitive to heat oxidation due to the presence of double bonds in its molecular structure. These drawbacks have been overcome by some approaches, for example .
