Improvement of flammability properties of acrylic rubber

Polyacrylic rubber (ACM) is obtained from the copolymerization of various acrylate monomers. Acrylates used; ethyl acrylate and/or butyl or octyl acrylate is ethylmethoxy or ethyloxy acrylate. The obtained acrylic rubbers are very resistant to oil, heat, aging and ozone. Tensile properties of acrylic rubbers are not as good as natural and nitrile rubbers. Especially the new generation ACMs can operate for 1000 hours at around 160-170°C. But they show softening at high temperatures. ACM vulcanizates are more resistant to swelling in animal, vegetable and mineral oils than other rubbers, except fluoro rubber (FKM), however this properties decreases with increase the heat. Acrylic rubbers also do not have good resistance to chemicals. Its dry running properties are bad, it is not suitable for use in low temperature and water. More than 90% of acrylic rubbers are used in the automotive industry. They are generally used as shaft seals in crankshafts, automatic and differential transmissions, as well as in o-rings, valves and oil hoses. High priced FKM are generally preferred in these applications in the industry. However, the prices of fluoro rubbers are on average 3 times higher when compared to ACM. In this study, it is aimed to use ACM rubber as an alternative material instead of FKM by increasing its non-flammability properties. By adding halogen-free flame retardant materials, the high temperature performance of ACM rubber is reported.