The effect of natural rubber on physical and mechanical properties of rubber seal for LPG tube valve

Abstract

The price of natural rubber (NR) continues to decline. In early January 2020 the price of Standard Indonesian Rubber (SIR) 20 was around 1.83 US$/kg and in May 2020 dropped to 1.09 US$/kg. Under this condition, NR downstream program becomes a necessity to increase domestic consumption of NR so that the sustainable rubber industry can be achieved. One prospective product and can be substituted using NR is the rubber seal for Liquified Petroleum Gas (LPG) tube valve. Based on the rubber seal quality requirements in Standar Nasional Indonesia (SNI) 7655: 2010, the rubber raw material should use rubber which is resistant to n-pentane. Nitrile Butadiene Rubber (NBR) synthetic rubber is suitable, meanwhile NR is not resistant to n-pentane so it is not suitable to produce rubber seal for LPG tube valve. Hence, this research studied the effect of NR on physical and mechanical properties of rubber seal compared to NBR compound. The results showed that NR improved elastic properties such as tensile strength, elongation at break and compression set, but decreased the resistance to n-pentane. Mixing NBR and NR with appropriate compositions can produce a better rubber seal for LPG tube valve.