Removal of lithium from polymer cements

Abstract

A process for preparing a polymer cement which is relatively free of alkali metal salt by preparing the polymer cement with a polymerization terminating agent which is an acid which leaves alkali metal salt in the cement which is readily removable by centrifugation.

We claim: 
     
       1. A process for removing alkali metal compounds from a polymer cement comprising: preparing polymer cement of conjugated dienes with a polymerization terminating agent which is an acid selected from 2-ethylhexanoic acid, 12-hydroxyl stearic acid, oxalic acid, benzoic acid, and succinic acid and which leaves alkali metal salt in the cement; and   removing the alkali metal salt from the polymer cement.   
     
     
       2. The process of claim 1 wherein the alkali metal is lithium. 
     
     
       3. The process of claim 1 wherein the polymer cement is a functionalized mono-ol or diol having a number average molecular weight between 1000 and 20,000. 
     
     
       4. The process of claim 1 wherein the terminating agent is oxalic acid. 
     
     
       5. The process of claim 1 wherein the terminating agent is benzoic acid. 
     
     
       6. The process of claim 1 wherein the terminating agent is 12-hydroxy stearic acid. 
     
     
       7. The process of claim 1 wherein the terminating agent is succinic acid. 
     
     
       8. The process of claim 1 wherein the alkali metal salt is removed from the polymer cement by centrifugation. 
     
     
       9. The process of claim 1 wherein the alkali metal salt is removed from the polymer cement by filtration.