Single stage continuous graft polymerization process and product

#1. Field of the Invention

#This invention relates to graft polymerization of synthetic rubber and methyl methacrylate polymers and copolymers.

#2. Description of the Prior Art

#Without intending to be limited thereto, the following examples are presented to illustrate a few embodiments of the invention. All parts and percentages throughout this disclosure are by weight unless otherwise indicated.

#In the following experiments, polymerization of the reaction mixture was conducted under continuous conditions in a single stage reaction process with temperature preferably at 161.degree.-195.degree. C., with residence time below 90 min., and achievement of 25-65% monomer conversion to polymer. The reactor vessel had a 1.7 gal. volume capacity and was fitted with a multi-bladed turbine agitator, operated preferably at 1000-2000 rpm to achieve turbent mass flow with Reynold's values to exceed 2100. The reaction was operated at 100-175 psig.

#"Steady state" polymerization conditions were achieved within five full reactor volumes from start-up. Start-up was accomplished by filling the 1.7 gal. stainless steel reaction vessel with the reaction mixture, pressurizing the reactor and contents to 100-175 psig, commencing agitation, increasing temperature to target conditions with the aid of external electrical heaters, and then continually delivering reaction mixture to the vessel at a finite rate while continually removing the partially polymerized reaction mixture from the vessel at an identical rate. Temperature of the reactor contents was monitored from thermocouples positioned at the top, middle, and bottom of the vessel.