MECHANISM OF ANIONIC (IONIC) POLYMERIZATION OF ACETYLENE MONOMERS

Polymerization of phenylacetylene in presence of butyllithium has been studied. It is shown that the process of polymerization is accompanie d by the appearance and growth of the ESR signal. The model of anionic polymerization is suggested according to which formation of low-molec ular-weight polyphenylacetylene is caused by the destruction of the ac tive centers by means of electron transfer from active center to the c onjugated chain. The assumption is made that electron transfer from co njugated chain to an active center may also be a fundamental reaction limiting the chain length in cationic polymerization of acetylene mono mers. The kinetic scheme of ionic polymerization of acetylene monomers with consideration of electron transfer is analyzed and molecular wei ght distribution functions are obtained with good agreement between th e calculated parameters and experiment. It is shown that one of the wa ys of obtaining high-molecular-weight polyacetylenes in ionic polymeri zation is the formation of donor-acceptor complexes with a polyene cha in in the process of the chain growth. The formation of complexes exch anges parameters of electron structure of the polyene chain and decrea ses the rate of the electron transfer reactions.