Preparation And Application Of Hydrogenated Conjugated Diene Polymer

Hydrogenation reaction of conjugated diene polymer, especially rubber-like polymer, has been an active field of research for a long time because hydrogenated rubbers include new or improved properties comparing to the base rubbers. Combination of living anionic polymerization and hydrogenation reaction for preparation of saturated olefin copolymers with a controlled architecture is an important research field. In this paper, throughout catalytic hydrogenation reaction, a series of homopolymer, block copolymer and random copolymer were hydrogenated by a Ziegler-Natta type catalyst with low cost, high activity and good solubility in cyclohexane, which was prepared with nickel naphthenate (Ni) as main catalyst and aluminum triisobutyl (Al) as assist catalyst. The effect of reaction condition on the extent of hydrogenation was investigated. A series of polymer materials with new structure were prepared.Designed molecular weight and monodisperse hydrogenated polybutadiene (HPB), deuterated polybutadiene (DPB), hydrogenated polyisoprene (HPI) and deuterated polyisoprene (DPI) were prepared by hydrogenation or deuteration of homopolymers (polybutadiene and polyisoprene). Alternating ethylene-propylene copolymer (alt-EP) was prepared for the first time by hydrogenation of polyisoprene (HCPI) having high cis-1,4content (～100%) with the catalyst mentioned above. A series of polyethylene-b-polybutylene (PE-b-PBt-1) samples with different block ratio were prepared by hydrogenation of low-vinyl-polybutadiene-b-high-vinyl-polybutadiene (LVPB-b-HVPB), which can be used as compatibilizer of polypropylene/linear low density polyethylene (PP/LLDPE). High cis-polyisoprene-b-polycaprolactone (HCPI-b-PCL), and styrene-isoprene-butadiene rubber (SIBR) were hydrogenated to prepare new materials. Star-shaped alt-EP (S-alt-EP), hydrogenated SIBR (HSIBR) and star-shaped HSIBR (S-HSIBR) can be used as viscosity index improver (VII) in lubricants due to their improved thermal and oxidative resistance. The relationship of microstructure and performance was investigated. When HSIBR was used as damping material, the effect of monomer content and hydrogenation degree on thermal oxidative stability and dynamic mechanical property was investigated. The main results and conclusions are as follows:The fully hydrogenated or deuterated products were obtained using homopolymer as hydrogenation substrate. The effect of reaction condition on the extent of hydrogenation was investigated. The optimum hydrogenation condition was as follows:catalyst amount,2mg Ni per each1gram of polymer; Al/Ni molar ratio,6; temperature,70℃; hydrogen pressure,4MPa; and time,3h.PE-b-PBt-1and alt-EP-b-PCL were prepared by hydrogenation using block copolymer as hydrogenation substrate. Used as compatibilizer of PP/LLDPE, impact strength and breaking elongation of blend increased with the increase of the compatibilizer content. In the blend with the PP/LLDPE molar ratio of8:2, compatibilization effect and mechanical properties increased with the decrease of PE block content in solubilizer.The results obtained from NMR, FTIR and WAXD indicated that alt-EP-b-PCL was block copolymer having high alternating ethylene and propylene block.HSIBR was prepared by hydrogenation using random terpolymer (SIBR) as hydrogenation substrate. The effect of reaction condition on the extent of hydrogenation of SIBR was investigated. The optimum hydrogenation condition was as follows:catalyst amount,2mg Ni per each1gram of polymer; Al/Ni molar ratio,6; temperature,60℃; hydrogen pressure,4MPa; polymer concentration,10%; and time,3h. HSIBR with hydrogenation degree of98%was obtained in the hydrogenation condition as mentioned above. Hydrogenation reaction kinetics of SIBR was also investigated in this paper. The results obtained from1H NMR indicated that the hydrogenation rates of microstructures decreased as follow:B1,2>B1,4>Ⅰ3,4>Ⅰ1,4.HSIBR can be used as Ⅶ in lubricant. The effect of molecular weight, microstructure and butadiene units content of HSIBR on performance as Ⅶ was investigated in this paper. The results indicated that HSIBR was a Ⅶ with outstanding shear stability and high HTHS viscosities, while maintaining correspondingly high thickening power and viscosity index, as well as excellent low-temperature fluidity.HSIBR can also be used as damping material. After mixing and vulcanizing, hydrogenated samples with different monomer ratio and different hydrogenation degree was obtained. Physical mechanical properties such as, aging, tensile and hardness (Shore A) experiments were investigated. The results indicated that with the increase of isoprene unit content, hardness of samples increased, the peak value of tan δ increased, and that with the increase of hydrogenation degree, hardness of samples decreased, aging property was improverd, the peak value of tan δ increased first, then decreased, storage modulus (E') decreased, loss modulus (E") decreased first, then increased. Content of isoprene play a very important role in damping capacity of polymer. Hydrogenated product obtain from SIBR with high isoprene content could be suitable for damping materials.