Study On Anionic Polymerization Of Butadiene And Styrene With Ethylbenzene-Cyclohexane Solvent

It is well known that the synthesis of rubber is an important part for the preparation of ABS Copolymers by continuous mass polymerization. In this paper, polybutadiene and butadiene-styrene copolymer for ABS polymerization was synthesized with ethylbenzene (EB) and cyclohexane as mixture solvent according to the principle of anionic polymerization. Furthermore, this technology was good for the process of rubber dissolution for economy and made the system in homogeneous.In this thesis, THF, self-made asymmetric ethers and sodium alkoxides were used as modifiers in anionic polymerization of butadiene and the copolymerization of styrene and butadiene in the cyclohexane and EB mixing solution with n-butyllithium as the initiator, in which asymmetric ethers were synthesized following the Darzens method include ethyl morpholinoethyl ether (EOEM) and sodium alkoxides include sodium salts of morpholinoethol (MEONa). Modifiers, dosage, reaction temperature were studied on polymerization rate by dilatometer. The false first-order apparent rate constant and activation energy were calculated as well. The microstructures of the products were calculated by FT-IR.GPC analysis showed that the molecular weight was reduced and the molecular weight distribution was broaden with the increasing of EB. The distribution index ranged from 1.2 to 2.5. The kinetics research indicates that the polymerization speed increased fast with the adding of the modifiers and the polar solvent.The microstructure research showed that the regulation ability of the modifiers were so strong that the 1,2-content of polybutadiene could be modified from 10% to 70% easily by altering the modifier concentration and the initiation temperature from 40℃to 60℃. The 1,2-content of polybutadiene could be modified from 10% to 15% easily by altering the solvent concentration.EOEM/MEONa composite system are used as modifiers in the random copolymerization of butadiene and styrene, and the block copolymerization of butadiene and styrene was synthesized with THF as additives. Microstructures, number average molecular weight and distribution were studied by H~1NMR and GPC. The microstructure of SSBR reached 68% with the modifier changes. In this paper, we synthesized a series of polymers with different microstructures, molecular weight and the copolymerization of butadiene and styrene with different monomers proportion for the synthesis of ABS Copolymers by continuous mass polymerization.The polymers which were synthesized in this thesis have the same molecular weight and microstructures comparing the rubbers which were purchased.