Explanation

The natural polymer materials extracted from the latex or tissue of rubber containing plants (woody or herbaceous) is mainly composed of polyisoprene. According to different molecular structures, it can be divided into cis natural rubber (such as clover rubber, chamomile rubber and dandelion rubber) and trans natural rubber (such as gutta percha, balata rubber and eucommia ulmoides gum)? Its molecular structure is as follows: ⑶, H>c, called -- CH2, CH2-CH2XCH3_ Type Tianpai rubber | (c) (_ ^ - |. * * '| "| |>^ knock 1 ^ |' magic trans natural rubber (" | 3 * (-0.4- | 50 knock 1 '<: here) natural rubber relative density 0.9.1, Mooney viscosity 50? 90, elasticity modulus reading 2? 4MKI. glass transition temperature -70? 72X 130? 140 ° C_ When bating? degradation starts at 200t. It has high elasticity at room temperature, and crystallization hardening 3 has good alkali resistance at low temperature, but it is not resistant to strong acids, and is insoluble in water, low-grade ketones and alcohols. It can swelling in non-polar solvents such as methyl chloride, carbon tetrachloride, etc. At present, only Brazilian clover rubber trees have achieved large-scale commercial cultivation and development, so natural rubber often refers to Brazilian leaf rubber in some cases. natural rubber is widely used in the manufacture of tires, medical products, seals, etc.

Classification