Anionic Synthesis Of POSS End-functionalized Ssbr And Interactions With Filled Silica

The polymeric organolithiums are directly reacted with the electrophilic reagents(terminator)to get the ω-end-functionalized polymers by the living anionic polymerization technique,increase interaction between the polar end groups of the terminator in polymer and silica.It is also one of the effective methods to solve the current hysteresis energy loss.We choose polyhedral oligomeric silsesquioxane(POSS)as terminator,it may form hydrogen bonding interaction with the hydroxyl groups of silica,and then can reduce the hysteresis energy loss.Chloropropyl heptaisobutyl polyhedral oligomeric silsesquioxane end-functionalized polybutadiene(PB-POSS)has been synthesized using butadiene as monomer,Cl-POSS as terminator,n-BuLi as initiator,tetrahydrofuran(THF)as structural modifier,cyclohexane as solvent by living anionic polymerization.The results of 1H-NMR,13C-NMR and GPC proved that poly(butadienyl)lithium was terminated with POSS to form PB-POSS.Then the mixture of silica-filled PB-POSS was prepared by solvent method and the content of the PB-POSS bound rubber was determined by the extraction method.The molecular weight of PB-POSS,the content of silica and the content of Si69 coupling agent,affecting the PB-POSS bound rubber content were investigated also.The results shown that the bound rubber content reached the highest values when the silica content was 50 per hundred,the Si69 content was 2.5 per hundred,and the bound rubber content of all PB-POSS samples were much higher than that of PB.Then the initiator type,the rubber type affecting the bound rubber content were investigated also.The results shown that the bound rubber content of PB-POSS samples were slightly higher than that of SSBR,and the bound rubber content used dilithium as initiator were much higher than that of n-BuLi.The thermal stability of PB-POSS is investigated by steam stripping method,simulating the industrial production.The experiments indicated that the end chemical bonds of the PB-POSS had the high thermal stability at different steam stripping time.The mechanism of the interaction between PB-POSS and silica was studied by FTIR.The results of FTIR shown that after silica or Si69 modified silica filled PB-POSS,the absorption peaks of Si-OH bond shift toward lower wavenumber region and the intensity of Si-OH absorption peak increased significantly,which demonstrated that there was strong hydrogen bonding interaction between silica and PB-POSS and explained the change rule of the bound rubber content.