We usually speak of natural rubber, which refers to the natural latex from rubber trees collected and after solidification, drying processes are made of solid material. Natural rubber is a polymer of isoprene as the main ingredient of natural polymers, the molecular formula is (C5H8) n, the polymer (Poly isoprene) content in the above 90%, also contains a small amount of protein, fatty acids, sugars and ash, and so on. The physical properties of natural rubber. Natural rubber at room temperature, has high elasticity, slightly plastic, has a very good mechanical strength, hysteresis losses, in the many variants low heat, so the Flex is also very good, and because non-polar rubbers, so good electrical insulation properties. Chemical properties of natural rubber. Because has not saturated double bond, natural rubber is a chemical reactions capacity strong of material, light, and hot, and ozone, and radiation, and flexor flexible deformation and copper, and manganese, metal are can promote rubber of aging, not resistance aging is natural rubber of fatal weaknesses, but, added has antioxidant of natural rubber, sometimes in Sun Xia exposure two months still see not out more big changes, in warehouse within storage three years Hou still can as usual using.