Process for hydroxyalkylating carboxylic acid-functionalized materials
View Patent ↗The present invention relates to a process for hydroxyalkylating terminal carboxylic acid groups. More specifically, this invention provides a process for preparing hydroxyl-functionalized materials, such as butadiene nitrile polymers, from carboxylic acid-functionalized materials, such as butadiene nitrile polymers, using a carbocyclic carbonate, such as ethylene carbonate, or a carbocyclic sulfite, such as ethylene sulfite.
1. A process for preparing a dihydroxyl-functionalized material by hydroxyalkylating a dicarboxylic acid-functionalized material, said process comprising the step of: reacting as reactants: (a) a dicarboxylic acid-functionalized material selected from the group consisting of dicarboxylic acid-functionalized polymers of: polybutadiene, poly(butadiene-co-acrylonitrile), poly(acrylonitrile) and combinations thereof; and (b) a hydroxyalkylating reagent selected from the group consisting of: a carbocyclic carbonate, a carbocyclic sulfite and combinations thereof; in the presence of: (c) a phase transfer catalyst under conditions sufficient to form a dihydroxyl-functionalized material;
wherein said dihydroxyl-functionalized material has a molecular weight that is substantially unchanged relative to the molecular weight of said dicarboxylic acid-functionalized starting material.
2. The process according to claim 1 , wherein said dicarboxylic acid-functionalized material has carboxyl-functional groups independently selected from the group consisting of: R and R 1 , wherein each R and R 1 is independently selected from the group consisting of: COOH or CAA 1 —X—COOH, wherein each A and A 1 is independently selected from the group consisting of: hydrogen, halogen, cyano, linear or branched alkyl having from 1 to about 5 carbon atoms and wherein X is a linear or branched alkyl having from 1 to about 5 carbon atoms.
3. The process according to claim 1 , wherein said dicarboxylic acid-functionalized material has a number average molecular weight of from about 3,100 to about 4,200.
4. The process according to claim 1 , wherein said hydroxyalkylating reactant is a member selected from the group consisting of carbocyclic carbonate and carbocyclic sulfites.
5. The process according to claim 4 , wherein said carbocyclic carbonate is a member selected from the group consisting of ethylene carbonate, 1,3-propylene carbonate, 2-methyl-1,2-ethylene carbonate, 3-methyl-1,3-propylene carbonate, 1,2-dimethyl ethylene carbonate, 2,2-dimethyl butylene carbonate and combinations thereof.
6. The process according to claim 4 , wherein said carbocyclic carbonate is ethylene carbonate.
7. The process according to claim 4 , wherein said carbocyclic sulfite is a member selected from the group consisting of ethylene sulfite, propylene sulfites and combinations thereof.
8. The process according to claim 4 , wherein said carbocyclic sulfite is ethylene sulfite.
9. The process according to claim 1 , wherein said dihydroxyl-functionalized material is selected from the group consisting of the dihydroxyl-functionalized polymers of: polybutadiene, poly(butadiene-co-acrylonitrile), polyacrylonitrile, and combinations thereof.
10. The process according to claim 1 , further comprising the step of providing an amphoteric treating agent in an amount sufficient to cause said dihydroxyl-functionalized material to separate from the reactants which remain and/or any by-products thereof.
11. The process according to claim 10 , wherein said amphoteric treating agent is a member selected from the group consisting of silicated magnesium oxide, magnesium oxide, magnesium hydroxide, calcium hydroxide, barium hydroxide and combinations thereof.
12. The process according to claim 1 , wherein said phase transfer catalyst is a member selected from the group consisting of quaternary ammonium halides, phosphonium halides, sulfonium halides, crown ethers, calixarenes and combinations thereof.
13. The process according to claim 1 , wherein said phase transfer catalyst is a member selected from the group consisting of tetrabutyl ammonium iodide, tetraethylammonium iodide, benzyl trimethyl ammonium chloride and ethyl triphenylphosphonium bromide.
14. The process according to claim 1 , wherein the molar ratio of said hydroxyalkylating reagent to said dicarboxylic acid-functionalized material is from about 3.8 to about 4.5.
15. The process according to claim 1 , wherein said carboxylic acid-functionalize material is a member selected from the group consisting of carboxylic acid-functionalized polybutadiene and carboxylic acid-functionalized poly(butadiene-co-acrylonitrile).