Commonly used methods for synthesis of petroleum resin thermal polymerization, polymerization, and free radical polymerization catalyzed by 3. In many physical and chemical properties of petroleum resin, softening point, hue is the most important. Its 50 ~140 softening point ℃, hue than L3, pale yellow to dark brown. Polymerization of C9 fractions on carbon nine petroleum resin color, softening point has great influence.
C9 petroleum resin by thermal polymerization reaction fractions in the reactor heat to about 260 ℃, first formed by two molecules of the polymer intermediates Diels-Alder addition, reacting with another molecule of polyethylene components, generate two free radicals and polymerization. Thermal polymerization of synthetic resin technology is simple, high yield, high temperature, high energy consumption, easy Coke, production, product quality-colored resin is low, only industrially for the production of coloured resin, its products are mainly used as rubber reinforcing agent, additives for concrete.
Petroleum resin-catalyzed polymerization of cationic addition polymerization, principally C9 monomer in the presence of a catalyst to form carbonium ion activity center, triggering chain polymerization and synthesis of petroleum resin. Activity center was greatly influenced by ion-pair dissociation degree, as reaction medium, solvents of different active centres are also different. Catalytic polymerization in synthesis of petroleum resin is the earliest and most extensive, much of the literature refers to synthesis of petroleum resin used in catalytic polymerization.
Free radical polymerization due to C9 molecules exist in a large number of unsaturated bonds (lone pair electrons), under the initiator of the formation of free radicals and lead to chain polymerization, synthesis products solid after termination of inhibitor. Petroleum resin used in free radical polymerization initiators are peroxide or their mixture of sodium and fatty acids, initiator of the relatively large amount and ratio on the quality of the product.