화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.37, No.22, 4090-4099, 1999
Synthesis and characterization of poly(vinyl ferrocene) grafted hydroxyl-terminated poly(butadiene): A propellant binder with a built-in burn-rate catalyst
The graft copolymer hydroxyl-terminated polybutadiene-g-polyvinyl ferrocene (HTPB-g-PVF) was synthesized free radically from HTPB and vinyl ferrocene (VF) in benzene, using azobisisobutyronitrile as the radical initiator at 75 degrees. The graft copolymer was analysed for its structural and thermal characteristics. The chemically bound ferrocene in HTPB-g-PVF, catalysis the oxygen up-take and oxidative degradation reactions of HTPB, and the mechanisms of the catalysis are discussed. The most probable grafting sites on HTPB and the mechanism of grafting also are discussed. The extent of the grafting, which was a function of VF concentration, was low. The graft copolymer also was tried as a propellant-binder-cum-burn-rate (BR) catalyst in a composite solid propellant, using toluene diisocyanate and trimethylol propane as curatives with dibutyl tin dilaurate as the curing: catalyst, and the BRs of the propellants were evaluated at 3.9 MPa. The BRs increased with the extent of VF grafting but not proportionally. The BRs also were compared with those of reference HTPB propellants containing VF, Fe2O3, copper chromite, and so forth as BR catalysts. Chemically linked ferrocene in the binder augmented the propellant BR, probably because of the presence of catalytically active sites in the binder for its degradation.