| 摘要 |
<p>To control the molecular weight of a propylene homo- or co-polymer at a constant level when subjecting propylene alone, or together with another alpha -olefin, to bulk polymerization in the presence of hydrogen as a molecular weight modifier, the polymerization is performed in a reaction tank equipped with a reflux condenser, using liquid monomer as the reaction medium. The molecular weight is controlled at a desired level, by constantly measuring the quantity of heat removed from the reaction tank and constantly calculating the volume of hydrogen to be consumed, on the basis of the above-measured quantity of removed heat and the volume (X) of hydrogen consumed per unit amount of polypropylene, which volume (X) is obtained by utilizing the relation In eta =InX+A. (A being a constant and eta being the intrinsic viscosity of the propylene polymer). Hydrogen is charged into the reaction tank in quantities corresponding to variations in the calculated quantity.</p> |
