Hydrogenation of polybutadiene and butadiene-vinyltrimethylsilane copolymers in the presence of metal-complex catalysts

The hydrogenation of double bonds in polybutadiene and in the copolymers of butadiene with vinyltrimethylsilane synthesized by anionic polymerization is carried out in the presence of a rhodium metal-complex catalyst. The pro cess proceeds at a temperature of 110-115 degreesC and a hydrogen pressure of 50-60 atm. up to 100% conversion. It was shown that, in the course of bu tadiene copolymerization with vinyltrimethylsilane, the content of cis unit s in the butadiene part of the copolymer decreases sharply compared to the butadiene homopolymer prepared under the same conditions. The T-g of the bu tadiene-vinyltrimethylsitane copolymers is higher by 30-40 degreesC than th at of polybutadiene. A substantial increase in the T-g of the copolymers an d the appearance of a crystalline phase are registered as a result of hydro genation. In the case of polybutadiene, hydrogenation leads to the formatio n of crystalline polyethylene with the number of branchings equal to the co ntent of 1,2-units in the starting polymer.