Flexible to rigid nanoporous polyurethane-acrylate (PUAC) type materials for structural and thermal insulation applications

Patent metadata

Field	Value
Publication number	US-9550846-B2
Application number	US-201414208892-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 13, 2013
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

Novel urethane-acrylate (UAC) Star monomers and polyurethane-acrylate (PUAC) aerogel polymers derived therefrom are described herein, along with other novel, related monomers and polymers. Also described herein are processes for preparing the UAC Star monomers, the PUAC aerogel polymers, and the other related monomers and polymers. The PUAC and related polymers herein are useful in various applications including in structural and thermal insulation.

First claim

What is claimed is:

1. A nanoporous material comprising a polyurethane-acrylate polymer formed by the polymerization of a urethane-acrylate star monomer of the formula (I):

in the presence of a polymerization catalyst at 60° C. for 2-4 h, to give a wet gel, followed by aging of the wet gel for 24 h at 60° C., washing five times with acetone for 8 h per wash, and drying with supercritical fluid CO 2 ;
wherein the nitrogen atoms of the urethane moieties in the urethane-acrylate star monomer of the formula (I) are independently attached to their respective aryl rings at the 2, 3, or 4-positions of the aryl rings;
wherein each of W, X, and Y independently represents a C 1 -C 6 straight chain alkyl group or a C 1 -C 6 branched alkyl group;
wherein each of R1-R9 is independently a hydrogen, a C 1 -C 6 straight chain alkyl group, or a C 1 -C 6 branched alkyl group; and,
wherein the material is an aerogel.

2. The material of claim 1 , wherein the polymerization catalyst is a free radical initiator.

3. The material of claim 2 , wherein the free radical initiator is 2,2′-azobisisobutyronitrile.

4. The material of claim 1 wherein in the polyurethane-acrylate polymer the nitrogen atoms of the urethane moieties are attached to their respective aryl rings at the 4-positions of the aryl rings.

5. The material of claim 1 wherein in the polyurethane-acrylate polymer W═X═Y═CH 2 CH 2 .

6. The material of claim 1 wherein in the polyurethane-acrylate polymer each of R1-R9 is a hydrogen.

7. The material of claim 1 wherein in the polyurethane-acrylate polymer the nitrogen atoms of the urethane moieties are attached to their respective aryl rings at the 4-positions of the aryl rings; wherein W═X═Y═CH 2 CH 2 ; and wherein each of R1-R9 is a hydrogen.

8. A process for the preparation of the nanoporous material of claim 1 , the process comprising the step of treating a mixture of the urethane-acrylate star monomer in an organic solvent with a polymerization catalyst at 60° C. for 2-4 h, to give a wet gel, followed by the step of aging of the wet gel for 24 h at 60° C., the step of washing five times with acetone for 8 h per wash, and the step of drying with supercritical fluid CO 2 .

9. The process of claim 8 , wherein the organic solvent is selected from the group consisting of a ketone solvent, an ester solvent, and a combination thereof.

10. The process of claim 8 , wherein the organic solvent is acetone, ethyl acetate, or a combination thereof.

11. A one-pot process for the preparation of the nanoporous material of claim 1 , the process comprising the steps of:
(a) preparing a solution of the urethane-acrylate star monomer by mixing a tris(isocyanatophenyl)methane of formula (III)

with three molar equivalents of a hydroxyacrylate compound of the formula (IV)

in an organic solvent;
(b) treating the solution of the urethane-acrylate star monomer with a polymerization catalyst at 60° C. for 2-4 h to give a wet gel;
(c) aging of the wet gel for 24 h at 60° C.;
(d) washing five times with acetone for 8 h per wash; and,
(e) drying with supercritical fluid CO 2 ;
wherein each of R1-R3 is independently a hydrogen, a C 1 -C 6 straight chain alkyl group, or a C 1 -C 6 branched alkyl group.

12. A nanoporous material comprising a polyurethane-acrylate polymer formed by the copolymerization of a urethane-acrylate star monomer of the formula (I):

with a polymerization chain extender, in the presence of a polymerization catalyst at 60° C. for 2-4 h, to give a wet gel, followed by aging of the wet gel for 24 h at 60° C., washing five times with acetone for 8 h per wash, and drying with supercritical fluid CO 2 ;
wherein the nitrogen atoms of the urethane moieties in the urethane-acrylate star monomer of the formula (I) are independently attached to their respective aryl rings at the 2, 3, or 4-positions of the aryl rings;
wherein each of W, X, and Y independently represents a C 1 -C 6 straight chain alkyl group or a C 1 -C 6 branched alkyl group;
wherein each of R1-R9 is independently a hydrogen, a C 1 -C 6 straight chain alkyl group, or a C 1 -C 6 branched alkyl group; and,
wherein the material is an aerogel.

13. The material of claim 12 , wherein the polymerization chain extender is a compound comprising from 2 to 4 acrylate groups or from 2 to 4 methacrylate groups, or a combination thereof.

14. The material of claim 13 , wherein the chain extender is a compound comprising 2 acrylate groups.

15. The material of claim 14 , wherein the chain extender is a diacrylate compound of formula (V):

wherein L represents a linker group selected from C 1 -C 12 straight chain or branched chain alkyl, alkoxyalkyl, alkoxycarbonylalkyl, and alkoxycarboxyalkyl; and
wherein each of R10 and R11 is independently a hydrogen, a C 1 -C 6 straight chain alkyl group or a C 1 -C 6 branched alkyl group.

16. The material of claim 15 , wherein the chain extender is a diacrylate compound selected from the group consisting of:

17. The material of claim 12 wherein in the polyurethane-acrylate polymer the nitrogen atoms of the urethane moieties are attached to their respective aryl rings at the 4-positions of the aryl rings.

18. The material of claim 12 wherein in the polyurethane-acrylate polymer W═X═Y═CH 2 CH 2 .

19. The material of claim 12 wherein in the polyurethane-acrylate polymer each of R1-R9 is a hydrogen.

20. The material of claim 12 wherein in the polyurethane-acrylate polymer the nitrogen atoms of the urethane moieties are attached to their respective aryl rings at the 4-positions of the aryl rings; wherein W═X═Y═CH 2 CH 2 ; and wherein each of R1-R9 is a hydrogen.

21. A process for preparing the nanoporous material of claim 12 , the process comprising the step of treating a mixture of the urethane-acrylate star monomer and the chain extender in an organic solvent with a polymerization catalyst at 60° C. for 2-4 h, to give a wet gel, followed by the step of aging of the wet gel for 24 h at 60° C., the step of washing five times with acetone for 8 h per wash, and the step of drying with supercritical fluid CO 2 .

22. The process of claim 21 , wherein the organic solvent is selected from the group consisting of a ketone solvent, an ester solvent, and a combination thereof.

23. The process of claim 21 , wherein the organic solvent is acetone, ethyl acetate, or a combination thereof.

24. A one-pot process for the preparation of the nanoporous material of claim 12 , the process comprising the steps of:
(a) preparing a solution of the urethane-acrylate star monomer by mixing a tris(isocyanatophenyl)methane of formula (III)

Assignees

• Univ Missouri

Inventors

• Leventis Nicholas
• Sotiriou-Leventis Chariklia
• Bang Abhishek

Classifications

• C07C67/30

  by modifying the acid moiety of the ester, such modification not being an introduction of an ester group · CPC title

• C08F222/10

  Esters · CPC title

• C07C69/74

  Esters of carboxylic acids having an esterified carboxyl group bound to a carbon atom of a ring other than a six-membered aromatic ring · CPC title

• C08F122/10 Primary

  Esters · CPC title

• C08F122/26

  of unsaturated alcohols {(C08F122/1006 takes precedence)} · CPC title