✍ Scribed by C. Tosi; A. Valvassori; F. Ciampelli
No coin nor oath required. For personal study only.
AMtraet--To account for the dependence of the amount of (CH2)2 groups contained in ethylenepropylene copolymers upon the composition and the product of reactivity ratios, we derived an equation containing two empirical parameters deduced from the i.r. spectrum of several copolymers, prepared by some vanadium based catalysts, and of the corresponding homopolymers of propylene. Our treatment shows that, with these catalysts, there is a probability of about 80 per cent for the entrance of an ethylene unit and of about 20 per cent of a normal propylene unit after an inverted propylene unit; it shows that two thirds of the propylene units in E-P diads add normally (i.e. at the methylene group).
* This means that the inverted unit can occupy any place in the chain except the first and the last. I" It should be noted that, in our notation, chains grow from right to left. * The i.r. spectra were recorded on a Perkin-Elmer 221 Spectrophotometer, with NaCI optics. The samples were examined as sheets, approximately 0.01 cm thick, pressed by die-casting.
📜 SIMILAR VOLUMES
The article describes the mechanical properties of a propylene-ethylene block copolymer (Co-PP) used as a matrix with acrylic acid (AA) and strengthened with glass fiber. Isotactic polypropylene (i-PP) is also used as a matrix to compare with the results obtained from the Co-PP grafting. Experimenta