Process for the preparation of non-microencapsulated monodisperse bead polymers

Abstract

Disclosed herein is the polymerization of monodisperse microencapsulated monomer droplets to produce monodisperse non-microencapsulated bead polymers through the addition strong alkalis or strong acids during the polymerization.

1 . A process for the preparation of non-microencapsulated monodisperse bead polymers, comprising: 
 a) preparing an aqueous suspension of 
 i) microencapsulated monodisperse monomer droplets containing monomer, crosslinking agent and free radical initiator and  
 ii) dispersant  
   b) initiating polymerization by increasing the temperature of the suspension to temperatures at which the free radical initiator is active,    c) conducting the polymerization to a polymerization conversion of 20 to 98%,    d) adding strong acids or strong alkalis to c),    e) completing the polymerization and    f) isolating the resulting non-microencapsulated monodisperse bead polymer.    
     
     
         2 . A process according to  claim 1 , wherein the monomer droplets are microencapsulated with a gelatin-containing capsule wall.  
     
     
         3 . A process according to  claim 1 , wherein the addition of strong acids or strong alkalis is added at a polymerization conversion of 20 to 98%.  
     
     
         4 . A process according to any of  claim 1 , wherein the strong alkali used is sodium hydroxide.  
     
     
         5 . A process according to  claim 4 , wherein the sodium hydroxide is used in an amount to provide concentration of sodium hydroxide in the aqueous phase of 0.1 to 5% by weight.  
     
     
         6 . A process according to  claim 1 , wherein the microencapsulated monomer droplets substantially comprise styrene and divinylbenzene.  
     
     
         7 . A process according to  claim 1 , wherein the microencapsulated monodisperse monomer droplets additionally contain a porogen.  
     
     
         8 . Non-microencapsulated monodisperse bead polymers obtained by 
 a) preparing an aqueous suspension from 
 i) microencapsulated monodisperse monomer droplets containing monomer, crosslinking agent and free radical initiator and  
 ii) dispersant,  
   b) initiating the polymerization by increasing the temperature to temperatures at which the free radical initiator is active,    c) effecting polymerization to a polymerization conversion of 20 to 98%,    d) adding strong acids or strong alkalis,    e) completing the polymerization and    f) isolating the resulting non-microencapsulated monodisperse bead polymer.    
     
     
         9 . A method of preparing ion exchangers or cation or anion exchangers, particularly for anion exchangers for use in a mixed bed comprising providing the non-microencapsulated monodisperse bead polymers according to  claim 8  in seed/feed processes for the preparation thereof.  
     
     
         10 . An adsorber obtained by a process according to  claim 1 , wherein the microencapsulated monodisperse monomer droplets additionally contain porogens.