廣事2孝大学 十CH2C=CHCH, Guangdong University of Technolopy natural rubber CH3 Types of rubbe polybutadiene synthetic rubber Polyisobutene (Breathable) Neoprene rubber(oil resistant) Hevea Brasiliensis橡胶树 Goodyear TireTypes of rubbe CH2 C CH CH3 n CH3 natural rubber synthetic rubber Goodyear Tire Hevea Brasiliensis 橡胶树 polybutadiene Polyisobutene (Breathable) Neoprene rubber (oil resistant)