Topochemical Polymerization of 1,3-Diene Monomers To Control Polymer Structure

摘要

Many reports have been published on the polymer structure control by radical polymerization, which is the most convenient and important process for the production of vinyl polymers. In contrast to the recent progress in the control of the molecular weight and its distribution and of the chain ends and branching structures, the control of tacticity is still difficult due to the free radical propagating species. Topochemical polymerization in the crystalline state is the most promising method for controlling the stereochemistry of polymer chains, and to give polymer crystals with a structure that is strictly determined by the crystal structure of the monomers. Recently, we have reported that the esters and alkylammoniums of (Z,Z)-muconic acid provide a high molecular weight and stereoregular polymer under UV irradiation in the crystalline state. Crystal engineering is the planning of syntheses in the crystalline state and the evaluation of the structure and properties of the crystalline products, and it is very useful for the control of tacticity and molecular weight as the primary structure of polymers and of polymer crystalline structures. In this paper, the topochemical polymerization of the alkyl esters and the alkylammonium salts of (Z,Z)-, (E,Z)-, and (E,E)-1,3-diene mono- or dicarboxylic acids, i.e., of the muconic and sorbic acid derivatives (Scheme 1), is described from the view point of polymer crystal engineering.