Tensile and oil resistance properties of chloroprene added in epoxidized natural rubber, nitrile butadiene rubber, and poly vinyl chloride blends

Abstract

In order to enhance the oil resistance of natural rubber (NR) and Epoxidized natural rubber (ENR), this research was investigated the effect of chloroprene addition as compatibilizer into natural rubber (NR), nitrile butadiene rubber (NBR), and poly vinyl chlorides (PVC) blends. The study aims to examine the effect of CR addition into NR and ENR blends with NBR, PVC on physical mechanical, tensile and oil resistance properties of the thermoplastic elastomer / blends. ENR was prepared using natural rubber latex (30% DRC), 1 M formic acid, 1M acetic acid glacial at temperature 70-80°C for about 6 hours. The CR was added 0; 2,5; 5; 7,5; 10 phr into both NR/NBR/PVC and ENR/NBR/PVC blends. The mastication, blending and rubber compounding were conducted based on the ASTM procedures. The results show that at similar blend ratio composition of CR/NBR/PVC, ENR possess slight higher hardness values and better oil resistance compared to NR blends. However, tensile strength, elongation at break, and modulus of NR blends is not significantly different from ENR. In terms of change mass and the changes value of tensile strength and hardness after oil immersion, ENR blends that has oxirane group has better properties rather than NR blends. The CR addition could present a chlorine atom that restrict oil diffusion and oil absorption into the blends, thus it might lower the change mass and enhance the oil resistance. The CR loading also give positive trends in tensile strength, elongation at break for both NR and ENR blends, but an adverse effect on the modulus 100% elongation. In addition, the higher CR added, the smaller changes on tensile strength and hardness after oil immersion in both NR and ENR blends. It could be inferred that CR addition is able to improve compatibility and process-ability of the NBR, ENR, NR, and PVC blends using a proper plasticizer.