Stereoregularity acrylonitrile polymer and constituent null for stereoregularity acrylonitrile polymer formation

摘要

PURPOSE:To improve the fiber-forming properties and drawability of a linear acrylonitrile polymer by specifying the mol.wt., isotactic triad fraction, and syndiotactic triad fraction of the polymer. CONSTITUTION:A linear stereoregular acrylonitrile polymer which has a viscosity average mol.wt. of 50000 or higher and of which an isotactic triad fraction (I) and a syndiotactic triad fraction (S) satisfy the relations, I0.4 and 1+3S0.95. The polymer includes not only an acrylonitrile homopolymer but also a copolymer contg. at least 50wt.% acrylonitrile units, is obtd. by the polymn. using an initiator comprising an organometallic compd., exhibits such a high crystallizability that the m.p. increases in the presence of water, and has an excellent drawability and other processabilities in fiber-forming process. When the polymer is formed into fiber, it gives a fiber excellent in the mechanical strengths and wet-heat resistance.