Curing reactions in acetylene-terminated resins. Part 5.—Cyclotrimerization versus linear polyene formation in the catalysed cure of ethynylaryl-terminated monomers
Abstract
Structural differences in the polymers obtained by catalysed cure of the ethynylaryl-terminated monomer [1,4-(1,3-HCCC6H4CH2O)C6H4]2CMe2(1) could not be detected by IR or NMR spectroscopy. However, a study of the solvent-free catalysed polymerization of the model monomer, phenylacetylene, showed that the extent of cyclotrimerization decreased in the order (η-Cp)Co(CO)2≫(η-Cp)2Ni≈(PPh3)2NiCl2≫(PPh3)2PdCl2 with an accompanying increase in the degree of linear polyene formation, suggesting that this is so also for the catalysed cure of 1.