Isocyanate-free synthesis of carbonate-modified polymers
The present invention relates to an isocyanate-free and preferably solvent-free process for preparing polymers containing five-membered cyclic carbonate groups. In particular, the present invention is directed to a process for preparing polymers bearing cyclic carbonate groups by reacting carboxyl-bearing polymers selected from the group including polyesters based on di- or polyols and di- or polycarboxylic acids or derivatives thereof or poly(meth)acrylates, with hydroxyl-functionalized five-membered cyclic carbonates, without addition of isocyanates.
1. A two-stage process for preparing polymers bearing five-membered cyclic carbonate groups by reacting carboxyl-bearing polymers selected from the group comprising polyesters based on di- or polyols and di- or polycarboxylic acids or derivatives thereof or poly(meth)acrylates, with hydroxyl-functionalized five-membered cyclic carbonates, without addition of isocyanates.
2. The process according to claim 1 , wherein the reaction is conducted in the presence of a catalyst.
3. The process according to claim 2 , wherein the catalyst is selected from titanium-free Lewis acids.
4. The process according to claim 2 , wherein tin-containing Lewis acids are used as catalyst.
5. The process according to claim 1 , wherein the hydroxyl-functionalized five-membered cyclic carbonate is glycerol carbonate.
6. The process according to claim 1 , wherein, in a first reaction step, the carboxyl-bearing polymers are prepared by polycondensation or polymerization, and the resultant carboxyl-bearing polymers are then reacted in a second reaction step with hydroxyl-functionalized five-membered cyclic carbonates.
7. The process according to claim 6 , wherein the carboxyl-bearing polymers are prepared in the first reaction step via a melt condensation.
8. The process according to claim 6 , wherein the polycondensation is effected at temperatures between 150 and 280° C. within 3 to 30 hours.
9. The process according to claim 1 , wherein the reaction is effected without solvent.
10. The polymers bearing cyclic carbonate groups and selected from the group comprising polyesters based on di- or polyols and di- or polycarboxylic acids or derivatives or poly(meth)acrylates thereof, obtained by a process according to claim 1 , where the polymers do not contain any isocyanates.
11. An isocyanate-free polyurethane formulation comprising the polymers bearing cyclic carbonate groups according to claim 10 .
12. The process according to claim 3 , wherein tin-containing Lewis acids are used as catalyst.
13. The process according to claim 2 , wherein the hydroxyl-functionalized five-membered cyclic carbonate is glycerol carbonate.
14. The process according to claim 2 , wherein, in a first reaction step, the carboxyl-bearing polymers are prepared by polycondensation or polymerization, and the resultant carboxyl-bearing polymers are then reacted in a second reaction step with hydroxyl-functionalized five-membered cyclic carbonates.
15. The process according to claim 14 , wherein the carboxyl-bearing polymers are prepared in the first reaction step via a melt condensation.
16. The process according to claim 7 , wherein the polycondensation is effected at temperatures between 150 and 280° C. within 3 to 30 hours.
17. The polymers bearing cyclic carbonate groups and selected from the group comprising polyesters based on di- or polyols and di- or polycarboxylic acids or derivatives or poly(meth)acrylates thereof, obtainable by a process according to claim 1 , where the polymers do not contain any isocyanates.
18. An isocyanate-free polyurethane formulation comprising the polymers bearing cyclic carbonate groups according to claim 17 .
19. The polymers bearing cyclic carbonate groups and selected from the group comprising polyesters based on di- or polyols and di- or polycarboxylic acids or derivatives or poly(meth)acrylates thereof, obtained by a process according to claim 1 , where the polymers do not contain any isocyanates.
20. An isocyanate-free polyurethane formulation comprising the polymers bearing cyclic carbonate groups according to claim 19 .