SYNTHESIS OF THE COPOLYMERS OF p-DIETHYNYLBENZENE WITH OTHER ACETYLENIC DERIVATIVE S INITIATED BY (Ph_3P)_2 PdCl_2

摘要

The copolymerization of p-diethynylbenzene （PDEB） with phenylacetylene （PhA）, 4, 4’-diethynylbiphenyl （DEBP）or m-diethynylbenzene （MDEB） are studied by varying mole ratios of monomers. When the mole ratios of PDEB/PhA are less or equal to 1/5, the copolymers are soluble and fusible, but the other copolymers are insoluble and infusible. The results show that the good solvent of cross-linked copolymers is benzene and their solubility parameter is 9.15 cal0.5.cm（-1.5）. And their swellability （θp）, Huggins parameter （χ）, density (d425) and the average molecular weights between crosslinks （c） are measured. It is found that θp and c of copolymers are greater but d425 is less than that of respective homopolymers. IR spectra show that the copolymers have transoid configuration and small number of unreacted ethynyl groups exist in the copolymers. The mechanism about the polymerization or acetylenic derivatives initiated by （Ph3P）2PdCl2 is discussed.