Compounds Involved S-C Bond For Radical Polymerization

Free radical initiator, one of the key research fields of polymer chemistry, is the most widely used for polymer synthesis. Our laboratory has synthesized a series of compounds containing C-O bond which have the ability to initiate the polymerization of unsaturated monomers. For example,2,8-Bis(benzoyloxy)azelaic acid diethyl ester and 2,5-Bis(benzoyloxy)hexanedioic acid diethyl ester, shown as Based on these studies, we tried some compounds containing the C-S bond to initiate common monomers to be polymerized. The following three compounds were chosen:1-sulfhydryl(pentachlorothiophenol)ethyl-benzene, Pentachlorothiophenol and 2,4-dichloro-benzenethiol (?).1-sulfhydryl(pentachlorothiophenol)eth-yl benzene was first synthesized and characterized, and the other two commercial compounds were carefully purified. They are all characterized by 1H-NMR, IR and MS.The contrast experiment of styrene and MMA was carried out by using the blank control test and the addition of three compounds. The results show that:the yield is higher than the blank when we add 1-sulfhydryl(pentachlorothiophenol)ethyl benzene and Pentachlor-othiophenol; The experiments could get a high degree of polymerization when 1-sulfhydryl(pentachlorothiophenol)ethyl benzene or 2,4-dichloro-benzenethiol was added in the MMA while the blank got nothing. It showed that 1-sulfhydryl(pentachlorothiophenol)ethyl benzene, Pentachlorothiophenol and 2,4-dichloro-benzenethiol expressed initiating activity. This thesis also considered the effects by ch-anging polymerization temperature、polymerization time、monomer concentration and initiator concentration of 1-sulfhydryl(pentac-hlorothiophenol)-ethyl benzene or Pentachlorothiophenol on styrene. It showed that with the increase of temperature、polymerization reaction time、initiator concentration and monomer concentration, the yield growth followed by a higher linear correlation. The Mn dropped with the increasing of the temperature and initiator concentration. It grew with the increasing of the monomer concentration. However, it did not change when the time increased. These phenomena showed the characteristics of polymerization. The MMA polymerization studied the effect of the polymerization temperature, polymerization time,monomer concentration and initiator concentration on 1-sulfhydryl(pentachlorothiophenol)-ethyl and 2,4-dichloro-benzenethiol. The experiment found that at 85℃ the MMA did not occur in thermal polymerization. The results show that with the temperature increased, polymerization reation time grew, the initiator concentration and monomer concentration on the growth, the polymer linear correlation yield will also get increasing. The Mn follows the step with time, temperature and monomer concentration increasing but presents a gradient relationship with initiator concentration.Finally we discussed the mechanism.