VINYL POLYMERS PREPARED VIA SUSPENSION POLYMERIZATION AND METHODS THEREOF

摘要

A method of producing vinyl polymer particles by suspension polymerization comprising: combining an aqueous media and a tricalcium phosphate to a reaction vessel; adding a pH stabilizing agent to the reaction vessel; adding a vinyl monomer to the reaction vessel; adding a peroxide initiator, e.g., which also generates CO2 as a result of primary or secondary decomposition, to the reaction vessel; adding surfactant or a water soluble free radical initiator to generate surfactant in situ to the reaction vessel; maintaining the reactor contents at greater than or equal to 90° C. until a density of a dispersed phase becomes substantially equal to that of a continuous phase; adding a blowing agent to the reaction vessel; raising the temperature of the reaction vessel to greater than or equal to 100° C.; and collecting polymer particles having a particle size distribution.

主权项

1. A method of producing vinyl polymer particles by suspension polymerization comprising:
combining an aqueous media and a tricalcium phosphate to a reaction vessel; adding a pH stabilizing agent to the reaction vessel; adding a vinyl monomer to the reaction vessel; adding a peroxide initiator, which also generates CO2 as a result of primary or secondary decomposition, to the reaction vessel; adding surfactant or a water soluble free radical initiator to generate surfactant in situ to the reaction vessel; maintaining the reactor contents at greater than or equal to 90° C. until a density of a dispersed phase becomes substantially equal to that of a continuous phase, thereby forming a suspension having an initial pH; optionally adding a second quantity of tricalcium phosphate and optionally a second quantity of surfactant or optionally a second quantity of water soluble free radical initiator to generate surfactant in situ to the reaction vessel; adding a blowing agent to the reaction vessel; raising the temperature of the reaction vessel to greater than or equal to 100° C. and holding at said temperature for greater than or equal to 1 hour; and collecting polymer particles.