Initiating system Me3SiCl/AlCl3 for cationic polymerization of 1,3-pentadiene in toluene

Cat:ionic polymerization of 1,3-pentadiene (PD) initiated by trimethylsilyl chloride/aluminium chloride (TMSCl/AlCl3) was carried out in toluene at 30 degrees C. The polymer yield was increased by the addition of TMSCl. However, introduction of TMSCl gave rise to a drop of the polymer molecular weight. Kinetic results demonstrated that the polymerization initiated by TMSCl/AlCl3 was 2.8 times faster than that induced by AlCl3 alone. Various ethers and ketones were used to mediate the initiating system TMSCl/AlCl3. The polymer yield and molecular weight of the polymer were decreased in the presence of ether. Ketones and ethers had different effects on the polymerization, and the polymer yield and molecular weight were lower than those initiated by AlCl3 alone or TMSCl/AlCl3. Structural evidence revealed that the polymerization was indeed initiated by AlCl3 and HCl resulting from hydrolysis of TMSCl by adventitious water.