Method for preparing a vinyl polymer-polyolefine composite

A method for preparing a polyolefine-vinyl polymer composite, comprising:

• A. impregnating from about 10 to about 200 weight fractions of vinyl monomer and from about 0.01 to about 4.0 weight fractions of a free radical polymerization initiator, based on 100 weight fractions of vinyl monomer, by slowly blending said vinyl monomer and said initiator in 100 weight fractions of polyolefine particles at a temperature from about 20.degree. to about 100.degree. C. initially in the absence of water, and adding from about 1 to about 60% by weight water, based on the total weight of the vinyl monomer and said polyolefine particles, immediately after said polyolefine particles begin absorption of said vinyl monomer, the total impregnation time being between about 0.2 and 1 hour, the amount of water added being sufficient to maintain the particulate structure of said polyolefine;
• B. preparing a water suspension by adding water and a stabilizing agent to the above-mentioned mixture after a substantially completed impregnation of said vinyl monomer into said polyolefine, whereby the total quantity of water added is from about 80 to about 1000 weight fractions, based on 100 weight fractions of polyolefine +vinyl monomer;
• and
• C. increasing the temperature of the water suspension to a level sufficient for polymerizing said vinyl monomer.