Fundamental Investigations in Polymer Chemistry

摘要

Studies resulted in the first direct proof of chain transfer to solvent in the cationic polymerization of vinyl ethers by both chemical initiation and initiation using radiation. It was shown that incomplete dissociation of the initiator salt can influence the rate constant for polymerization by a factor of three or more. It was discovered that solvent effects can have remarkable effects upon the rate of polymerization. For example it was found that a linear relationship exists between the logarithms of the rate constants and the reciprocals of the dielectric constants. Results indicate that there is little or no solvation of the propagating species by monomer. In certain circumstances there could be a self-solvation of the propagating cations by their own chains. Progress on the radiation chemistry work on polyphosphazenes has moved slowly due to complicating factors caused by the broad and sometimes bimodal nature of the molecular weight distributions. (Author)