Curing reactions in acetylene-terminated resins. Part 2.—Differential scanning calorimetric, thermal gravimetric and thermomechanical analytical study of catalysed cure of an aryl prop-2-ynyl ether-terminated monomer
Differential scanning calorimetry (DSC) shows that the curing of the aryl prop-2-ynyl ether-terminated monomer(p-HCCCH2OC6H4)2CMe2(1) in the presence of (PPh3)3RhCl, (η-Cp)Co(CO)2, (η-Cp)2Ni, (PPh3)2NiCl2, or (PPh3)2PdCl2, takes place at lower temperatures and with lower enthalpies of polymerization than in the absence of the catalysts. Thermal gravimetry (TG) and thermomechanical analysis (TMA) studies indicate that when the resulting resins are crosslinked in the presence of catalysts they are less thermally stable and have lower Tg values than does the uncatalysed resin, the latter having a particularly rigid structure. The thermal stabilities of the resins decrease with decreasing ability of the catalysts to promote cyclotrimerization.