Method for improving the properties of polymers containing acrylonitrile

Claim 1

A METHOD OF MAKING ACRYLONITRILE-CONTAINING POLYMERIC BENDS WHICH ARE SUBSTANTIALLY FREE OF RESIDUAL ACRYLONITRILE AND DISCOLORATION COMPRISING THE STEPS OF: (1) POLYMERIZING AT A TEMPERATURE OF 65-100*C. A MONOMERIC MIXTURE COMPRISING 60-75 PERCENT BY WEIGHT OF VINYL ARYL MONOMER AND 25-40 PERCENT BY WEIGHT OF ACRYLONITRILE IN A AQUEOUS SUSPENSION IN THE PRESENCE OF A CATALYTIC AMOUNT OF A FREE RADICAL INITIATOR UNTIL THE POLYMERIZATION HAS PROGRESSED TO ABOUT THE BEAD IDENTITY POINT; (2) ADDING A BASE SELECTED FROM THE GROUP CONSISTING OF: (A) ALKALI METAL HYDROXIDE AND OXIDE; (B) ALKALINE EARTH METAL HYDROXIDE AND OXIDE WHEREIN SAID ALKALINE EARTH METAL HAS AN ATOMIC NUMBER OF 20-56 INCLUSIVE; (C) TETRAALKYL QUATERNARY AMMONIUM COMPOUNDS WHEREIN SAID ALKYL GROUP IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF METHYL, ETHYL, AND N,PROPYL; AND (D) ALKALI METAL SALTS OF WEAK ACIDS HAVING A PK OF AT LEAST 12.0; SAID BASE BEING ADDED IN AN AMOUNT SUFFICIENT TO MAINTAIN SAID BEADS IN A COLORLESS CONDITION; (3) THEREAFTER COMPLETING SAID POLYMERIZATION; AND (4) RECOVERING SAID POLYMERIC BEADS.

Claim 2

A METHOD OF MAKING ACRYLONITRILE-CONTAINING POLYMERIC BENDS WHICH ARE SUBSTANTIALLY FREE OF RESIDUAL ACRYLONITRILE AND DISCOLORATION COMPRISING THE STEPS OF: (1) POLYMERIZING AT A TEMPERATURE OF 65-100*C. A MONOMERIC MIXTURE COMPRISING 60-75 PERCENT BY WEIGHT OF VINYL ARYL MONOMER AND 25-40 PERCENT BY WEIGHT OF ACRYLONITRILE IN A AQUEOUS SUSPENSION IN THE PRESENCE OF A CATALYTIC AMOUNT OF A FREE RADICAL INITIATOR UNTIL THE POLYMERIZATION HAS PROGRESSED TO ABOUT THE BEAD IDENTITY POINT; (2) ADDING A BASE SELECTED FROM THE GROUP CONSISTING OF: (A) ALKALI METAL HYDROXIDE AND OXIDE; (B) ALKALINE EARTH METAL HYDROXIDE AND OXIDE WHEREIN SAID ALKALINE EARTH METAL HAS AN ATOMIC NUMBER OF 20-56 INCLUSIVE; (C) TETRAALKYL QUATERNARY AMMONIUM COMPOUNDS WHEREIN SAID ALKYL GROUP IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF METHYL, ETHYL, AND N,PROPYL; AND (D) ALKALI METAL SALTS OF WEAK ACIDS HAVING A PK OF AT LEAST 12.0; SAID BASE BEING ADDED IN AN AMOUNT SUFFICIENT TO MAINTAIN SAID BEADS IN A COLORLESS CONDITION; (3) THEREAFTER COMPLETING SAID POLYMERIZATION; AND (4) RECOVERING SAID POLYMERIC BEADS.