| 摘要 |
<p>This invention provides an improved process for mass polymerizing a solution comprising a monoalkenyl aromatic monomer having a diene rubber dissolved therein. The improvement comprises dissolving a minor amount of an aliphatic mono-olefinic compound in the solution, and then mass polymerizing the solution at temperatures of from about 80-180.degree.C, with agitation. Polymer molecules of the monomers are then formed as a matrix phase having a diene rubber dispersed therein as rubber particles grafted with and having occluded at least a portion of the polymer molecules. The olefin compound is selected such that during polymerization, the olefinic compound forms free radicals with the monoalkenyl aromatic monomer that are more active than a monoalkenyl aromatic free radical in chain transfer with the rubber increasing the grafting of the rubber with the polymer molecules. The improved process of this invention increases the grafting of the rubber phase yet allows the matrix phase polymers to reach optimum molecular weights consistent with optimum physical properties.</p> |
