合成橡胶（Synthetic rubber）.docVIP

合成橡胶（Synthetic rubber） Chapter 9 synthetic rubber Section 1 classification and performance of rubber The type of rubber Rubber: it is a kind of polymer elastomer. It can have a large deformation under the action of external forces. When the external force is relieved, it can quickly recover its original shape. There are two types of rubber Natural rubber: obtained from rubber tree, collected, condensing, washing, drying and so on. Synthetic rubber: polymerized by small molecule compounds, generally divided into general rubber and special rubber According to the use of synthetic rubber General rubber, special rubber The characteristics of rubber Glass has low temperature and high elasticity 3. Vulcanization and enhancement of rubber Unvulcanized: the large molecule is linear or branched, because its products are low in strength, small in elasticity, hard in case of cold, soft in heat and solvent, etc., so that the products are not worth using. Rubber products must be vulcanized to form a network or structure to have practical value. The proper vulcanization of rubber, which can keep rubber high elasticity, can also make rubber have certain strength. At the same time, in order to increase the product hardness, strength, abrasion resistance and tear resistance, and add an inert filler in machining process (such as zinc oxide, clay, chalk, barite, etc.) and reinforcing filler (such as carbon black), etc. The second standiene rubber Styrene butadiene rubber (SBR) : a polymer of 1, 3-butadiene and styrene. Industrial production methods: 1. Emulsion polymerization is legal and mainly adopted Variety: cold butadiene rubber, high temperature butadiene rubber, cryo-butylene rubber black rubber, low temperature filling butadiene rubber, high styrene styrene rubber, liquid butadiene rubber and so on. 2. Solution polymerization is legal Variety: alkyl lithium, alkene complex trigger, tin coupling, high trans-phenylene rubber. Emphasis: the production technology of low temperatur