Curative
A curative for epoxidized plant-based oils and epoxidized natural rubber is created from the reaction between a naturally occurring polyfunctional acid and an epoxidized plant-based oil is disclosed. The curative may be used to produce porosity-free castable resins and vulcanize rubber formulations based on epoxidized natural rubber. Materials made from disclosed materials may be advantageously used as leather substitutes.
1. A resin comprising a mixture of a pre-polymer and an epoxidized triglyceride, said pre-polymer comprising a reaction product among a naturally occurring polyfunctional carboxylic acid, a hydroxyl-containing solvent, and a second epoxidized triglyceride, wherein said pre-polymer includes a formed ester linkage between said hydroxyl-containing solvent and said naturally occurring polyfunctional carboxylic acid.
2. The resin according to claim 1 wherein said naturally occurring polyfunctional carboxylic acid is further defined as being selected from a group consisting of citric acid, tartaric acid, succinic acid, malic acid, maleic acid, and fumaric acid.
3. The resin according to claim 1 wherein said first and second epoxidized triglyceride are further defined as being selected from a group consisting of epoxidized soybean oil, epoxidized linseed oil, epoxidized corn oil, epoxidized cottonseed oil, epoxidized canola oil, epoxidized rapeseed oil, epoxidized grape seed oil, epoxidized poppy seed oil, epoxidized tongue oil, epoxidized sunflower oil, epoxidized safflower oil, epoxidized wheat germ oil, epoxidized walnut oil, and epoxidized microbial-produced oil.
4. The resin according to claim 1 wherein an additional polymer is added to increase the viscosity of the mixture.
5. The resin according to claim 4 wherein the additional polymer is selected from naturally occurring miscible polymers including shellac and epoxidized natural rubber.
6. The resin according to claim 1 wherein a plasticizer is incorporated.
7. The resin according to claim 6 wherein the plasticizer is selected from naturally occurring molecules and polymers.
8. The resin according to claim 7 wherein the plasticizer is selected from naturally occurring triglycerides having iodine numbers above 100.
9. The resin according to claim 7 wherein the plasticizer is a monounsaturated triglyceride.
10. The resin according to claim 7 wherein the plasticizer is a polymeric elastomer of epoxidized natural rubber.
11. The resin according to claim 1 wherein the resin is further formulated to include pigments.
12. A resin comprising a mixture of a pre-polymer and an epoxidized triglyceride, said prepolymer comprising a reaction product among a second epoxidized triglyceride and a naturally occurring polyfunctional carboxylic acid, wherein said pre-polymer is generated from the reaction product of the second epoxidized triglyceride and the naturally occurring polyfunctional carboxylic acid wherein the molar ratio of epoxide groups to carboxylic acid groups is between approximately 0.43:1 and 0.14:1.
13. The resin according to claim 12 wherein said pre-polymer further contains a formed ester linkage between a hydroxyl-containing solvent used as part of the reaction medium and said naturally occurring polyfunctional carboxylic acid.
14. The resin according to claim 12 wherein said naturally occurring polyfunctional carboxylic acid is further defined as being selected from a group consisting of citric acid, tartaric acid, succinic acid, malic acid, maleic acid, and fumaric acid.
15. The resin according to claim 12 wherein first and second epoxidized triglyceride are further defined as being selected from a group consisting of epoxidized soybean oil, epoxidized linseed oil, epoxidized corn oil, epoxidized cottonseed oil, epoxidized canola oil, epoxidized rapeseed oil, epoxidized grape seed oil, epoxidized poppy seed oil, epoxidized tongue oil, epoxidized sunflower oil, epoxidized safflower oil, epoxidized wheat germ oil, epoxidized walnut oil, and epoxidized microbial-produced oil.
16. The resin according to claim 12 wherein said resin is a mixture of more than 50 parts of pre-polymer to 80 parts of said second epoxidized triglyceride and less than 100 parts of pre-polymer to 50 parts of said second epoxidized triglyceride.
17. The resin according to claim 12 wherein said resin contains a net polyfunctional carboxylic acid content to combined first and second epoxidized triglyceride content between 25 parts of polyfunctional carboxylic acid to 100 parts of combined first and second epoxidized triglyceride and 50 parts of polyfunctional carboxylic acid to 100 parts of combined first and second epoxidized triglyceride.
18. The resin according to claim 13 wherein said hydroxyl-containing solvent comprises between 2.5 and 20 parts added to 100 parts of the pre-polymer.
19. The resin according to claim 18 wherein said hydroxyl-containing solvent is chemically reacted to said naturally occurring polyfunctional carboxylic acid.
20. The resin according to claim 12 that is added to a fabric carrier.