Polymerization Of Butene-1 With Supported Titanium Catalyst System

Adopting TiCl₄/MgCl₂-AlEt₃-DDS catalyst system, the effects of hydrogen pressure and n(DDS)/n(Ti) on isotacticity of polybutene-1 were studied in 3L polymerizer. It was showed that: the optimal-polymerization conditions of high isotacticpolybutene- 1 (94.1%) are: Hydrogen pressure=0.038MPa,n(DDS)/n(Ti)= 1.3. The effects of isotacticity on structure and properties of polybutene-1 were also studied in this experiment. With the increasing of the isotacticity of polybutene-1, the perfect of spherulite, the speed of crystallization,density, hardness,the heating stability, tensile strength, jield strength, modulus at 100%,modulus at 300% and permanent set will go rise,while toughness and elongation at break will drop down. From the comparison of structure, and properties between self-made and abroad high isotactic polybutene-1, the perfect of spherutite, melting point and the speed of crystal transformation of self-made -polybutene-1 are higher than abroad sample, but the degree of crystallinity of self-made polybutene-t is siightly lower, self-made polybutene-1 coincides with abroad sample in most parts such as the heating stability, molecular polydispersity and mechanical properties. Self-made polybutene-1 gets much close to the abroad high isotactic polybutene-1 in both structure and properties, which will give a good prospect in industrializing high isotactic potybutene-1 at inland.Polybutene-1 thermoplastic elastomer (PBt-TPE) was synthesized with the TiCl₄/MgCl₂-Al(i-Bu)₃ catalyst system.The effects of n(A1)/n(Ti), n(Ti)/n(Bt) and polymerization temperature on isotacticity, conversion ,and limiting viscosity number in 3L polymerizer in bulk polymerization at the presence of hydrogen pressure. It was showed that when n(A1)/n(Ti) is 300,polymerization temperature is30℃, the conversion reached its maximum. The effects of aging conditions, polymerization temperature and polymerization time on conversion, degree of crystallinity, relative molecular weight and mechanical properties in 500ml reaction bottle in solution polymerization.The conversion reached its maximum of 82.5%,when aging conditions were that n(Al)/n(Ti) is 100, aging temperature is 20℃and aging time is 20min. With the increase of polymerization time, relative molecular weight of PBt-TPE will rise while molecular polydispersity will become narrow. With the increase of polymerization temperature, isotacticity, tensile strenth, tear strength,modulus at 100%, modulus at 300% and hardness wiil increase first then decrease.There is the optimal properties when temperature is 3.0℃. On the same polymerization conditions, the effects of bulk polymerization and solution polymerization on structure and properties of PBt-TPE. Compared with bulk polymerization, isotacticity, the degree of crystallinity, limiting viscosity number, hardness, density, tensile strength, elongation at break, permanent set of PBt-TPE synthesized by solution polymerization were high.