Explanation

The process of polymerization in which monomer forms monomer free radicals directly under the action of heat without adding initiator. The reaction rate of thermal polymerization of most monomer is very slow. It is not easy to get repeated polymerization data due to the influence of a small amount of oxygen and peroxide in monomer. The thermal polymerization rate of styrene is fast, and repeated thermal polymerization data can be obtained. It is a typical process of polymerization using thermal polymerization process in industrial production. The thermal polymerization rate of styrene increases with the increase of temperature, the conversion rate reaches 50%, the polymerization takes 400 days at 29 ° C, the polymerization takes 25 hours at 100 ° C, and the polymerization takes only 16 minutes at 167 ° C. When the conversion rate increases to 85% -95% - the polymerization rate decreases significantly - so the polymerization temperature should be increased in the later stage of polymerization.

Classification