Polymerization of a-Methylstyrene by Means of Ziegler Catalyst and the Properties of Polymers Obtained

V. X-Ray Diagram of Poly-a-Methylstyrene

Abstract

X-ray scattering intensity curves of poly-a-methylstyrene prepared with various catalysts were obtained. They consist of two amorphous halos having maxima at the scattering angle of ca. 10°, and 16°, respectively. The spacings corresponding to these halos are 9.1 Å and 5.4 Å. The intensity ratio of the inner halo to the outer one increase and the scattering angle of the inner halo decrease with increasing stereoregularity of the polymer respectively. The order of the catalyst activity defined by the stereoregularity is as follows:
AlEt₃-TiCl₄=BF₃·OEt₂>TiCl₄>Na>K
The intensity ratio of the two halos increases with rising temperature when the polymer is heated above the glass transition temperature and also increases when treated with solvent such as methyl ethyl ketone or n-heptane.