Coordination Polymerization Of Diolefin With Supported Titanium Catalyst Modified By Alcohols

Supported titanium catalysts modified by alcohols were prepared for the first time, and the modified catalysts were used for the coordination polymerization of butadiene and isoprene. At room temperature, TPB were powdery resins with high crystallinity, while the polybutadienes prepared by alcohol modified titanium catalysts were elastomers with certain crystallinity. TPI were crystalline polymers like hard plastics, while the polyisoprene prepared by alcohol modified catalyst had obvious better elasticity than TPI.Coordination polymerization of butadiene with different kind and level of alcohols modified catalysts was investigated. The results showed that the mass fraction of 1,2-unit in the polybutadiene prepared by TiCli/MgCl₂ modified with primary alcohols were higher than those of the polymers synthesized by catalysts modified with secondary and tertiary alcohols. The mass fraction of 1,2-unit in the polymers fell within the range of the vinyl content of medium vinyl polybutadiene rubbers, the mass fraction of trans-1, 4-unit in the polymers were still above 50%, and the mass fraction of cis-unit in the polymers were typically lower than 10%. And with the increase of the contents of alcohols, the molar fraction 1,2-unit in the polybutadienes rose, whereas that of trans-1,4-unit decreased.The experiment of polymerizing butadiene with low level n-octanol(R0H/Ti≤4) modified catalyst was carried out. The effect of the level of alcohol, catalyst,Al(i-Bu)₃ and temperature on catalystic efficiency and the relative molecular mass was studied. The polymers were characterized with IR and DSC.The results showed that the Tm and the crystallinity of the polymers were lower than TPB. And the mass fraction of cis-1,4-unit, 1,2-unit and trans-1,4-unit in the polybutadiene synthesized by n-C₈H₁₇OH modified catalyst with ROH/Ti of 4 were 10. 3%, 38. 4%, 51. 7%. The optimum catalyst efficiency was obtainedat n-C8H,70H/Ti 3, Ti/Bd 5 x 1(T4,A1/Ti 20, temperature 60°C. The maximum value of the relative molecular mass were obtained at Al/Ti20, temperature 60°CoThe experiment of polymerizing butadiene with high level n-octanol and n-butanol (ROH/Ti ^10) modified catalyst was carried out. The effect of the level of alcohol, catalyst, Al(i-Bu):! and temperature on catalystic efficiency and the relative molecular mass was studied. The polymers were characterized with IR and DSC. Also the factors related with the content of insoluable part in the polymers were studied.The results showed that , in the polymers synthesized with n-octanol modified catalysts , the 3 -form crystalline has been eliminated , and the crystallinity of the a -form crystalline was only 1.7%. And in the polymers synthesized with n-butanol modified catalysts, the crystallinity of the a-, {3-form crystalline were below 10%. The Tm and crystallinity of the polymers were much lower than TPBO The mass fraction of 1,2-unit in the polymers synthesized by modified catalyst withn-GiH90H/Ti of 80 reached 90% or so, while the mass fracton oftrans-1,4-unit fell below 10%.the optimum catalyst efficiency was obtained at ROH/Ti20, Al/Ti 80, Ti/Bd 5x 10"\ temperature 60°C for catalyst modified by n-octanol, while at ROH/Ti 20, Al/Ti6 X 10"4, Ti/Bd 5 x 10^\ temperature 60°C ⁷0°C for catalyst modified by n-butanol. The relative molecular mass rose with the increase of alcohol level, while fell with the increase of titanium catalyst. The maximum value of the relative molecular mass were obtained at Al/Ti60⁸0, temperature 60°C. At room temperature, the mass fraction of insoluable part in the polymers synthesized with supported titanium catalyst modified by alcohols of high level fell with the increase of Al/Ti, Ti/Bd, catalyst preparation temperature and catalyst preparation time; while rose with the increase of polymerization temperature and polymerization time.Study is made on properties of polybutadienes which were synthesized by the solution polymerization method with alcohol modified catalyst in the 5L autoclaves . And comparison was made with BR9000 having the same basic formulation. The results show that when ROH/Ti is low(R0H/Ti is 4, 8), the processing properties of polybutadienes synthesized by modified catalyst is poor, and the strength of its rubber is inferior. When ROH/Ti is high(ROH/Ti>15), the processing properties of polybutadienes synthesized by modified catalyst is improved, and the strength of its rubber is good. The t,0 of the polybutadiene blends synthesized by modified catalysts was lower than that of BR9000 blend, while their tM, ML, MM were higher than those of BR9000 blend.The tensile strength, the modulus at 100% , shore A hardness, Goodrich heat buid-up ,the permanent set, the abrasion loss and the wet skid resistance index of polybutadiene vulcanizates synthesized by modified catalysts were higher than those...