Study On Copolymerization Of Butadiene/Styrene And Structure And Properties SSBR Under High Temperature

Solution polymerization styrene/butadiene rubber(SSBR) is one of the most important synthetic rubbers,which produced by organolithium initiators in the presence of polar modifiers to adjust the vinyl content of the diene polymers.The key synthesis technology of SSBR is polymerzation process and the selection of structure modifiers which can effect on stucture and properties of SSBR.In the recent years,the high temperature polymerization process widely used by worldwide outstanding rubber corporations because of high efficient and simple operation.In this paper,the anionic solution copolymerization of butadiene/styrene with n-butyllithium (n-BuLi),self-made asymmetric ehers,and hexane/cyclohexane solvent was studied experimentally in tank reactors of 5 liters.Polar modifiers are asymmetric ethers named as A,B,C,D.Furthermore this paper studies systematically the kinetic behavior of the copolymerization and the microstructure.The coupling reaction,molecular weight and its distribution of the SSBR were well discussed in detail.What's more,the vulcanization characteristic,mechanic properties and dynamic properties of SSBR were investigated.For the process equipment of research project,made a screening of the modifiers,and decided to use self-made asymmetric ehers as the modifier.Then modifiers,dosage,reaction temperature,initiator concentration were studied on polymerization rate and microstructure.It shows that the modifier an decrease block styrene content enve to the zero;through change the modifier's dosage we can control the vinyl content flexibly.And the randomizers regulation ability decreased in following order:A＞C＞D＞THF＞G₂.The study of kinetic shows that adding modifier to the anioni copolymerization system can increase the rate of polymerization significantly,and the sequence to the effect of the polymerization rate is as follows: A＞C＞D＞＞THF.Improving polymerization temperature can increase the rate of polymerization,but there is an optimum temperature;as increasing the dosage of modifier,the polymerization rate is improving,but the trend changed to be slow.Studied systematically on the kinetic behavior of the SSBR with A as modifier,we kown that the modifier have these properties as follow:well randomizers regulation ability,low sensitivity to temperature and high efficiency to coupling reaction,it also can improve the polymerization rate and effect the molecular distribution significantly.Furthermore,the research results of vulcanization show that we can get the produce of SSBR with excellent physical and mechanical properties by using self-made asymmetric ehers,the produce has both high wet skidding-resistance and low rolling-resistance properties,it has reached the properties target of overseas similar products.