3 lt 105 5 0 3 8mean particle size um 168 180bulk density g cm sub 3 0 392 0 389plasticizer sorption 128 1 124 4 parts 100 g resin funnel flow time g sec 5 3 5 2degree of polymerization 1113 1237inherent viscosity 1 03 1 07______________________________________ the presence of the expanding lattice clay with the hydroxypropylmethyl cellulose resulted in a significantly reduced polymerization time the procedure of example 1 was again repeated with the substitution of polyvinyl alcohol with and without veegum the results are shown in the following table table 4______________________________________ test no 9 10______________________________________test conditionsvinyl chloride wt 100 100water wt 200 200polyvinyl alcohol wt 0 13 0 13veegum wt 0 13 0 09di 2 ethyl hexyl peroxy 0 038 0 05dicarbonate wt reaction conditionstemperature u00b0 c 55 55rpm 600 500ph 8 5 4 7reaction times hrs 8 6 3conversion wt 71 86 1test resultsparticle size um 350 6 0 29 7250 29 1 37 5177 32 7 14 6149 15 3 5 0105 9 7 3 7 lt 105 7 3 9 6mean particle size um 192 245bulk density g cm sub 3 0 377 0 439plasticizer sorption 126 5 101 7 parts 100 g resin funnel flow time g sec 5 0 5 3______________________________________ the results evidence that the presence of the expanding lattice clay with the hydroxypropylmethyl cellulose increased the bell shaped pattern of distribution of the particles this was shown in the particle size distribution and in the mean particle size results the use of the protective colloid of this invention in the polymerization of vinyl chloride significantly improves the polymerization in most instances the polymerization time is significantly reduced in all cases the presence of the protective colloid enhanced the.