Polyurethanes, polyurethane foams and methods for their manufacture
View Patent ↗Polyurethane foams are described, as well as the production of such polyurethane foams by the reaction between a natural polyol, such as sucrose or a blend of mono- or disaccharides in place of the standard hydrocarbon-based polyol component, an ionic liquid or a deep eutectic solvent, a polyisocyanate and water in the presence of a suitable polyurethane forming catalyst and optionally a flame retardant, and optionally one or more components such as surfactants and/or emulsifiers. The resultant polyurethane foam can exhibit a bio-based solid content ranging from about 17% to 30%, may be formulated in a variety of foam densities for a variety of applications, and in the instance where a flame retardant has been added in an appropriate amount, exhibits a high degree of fire and burn resistance, as exhibited by the flame spread index and/or the smoke spread values.
1. A method for preparing a water blown, low density, polyurethane foam, the method which comprises:
contacting a first reaction mixture consisting of at least one polyisocyanate in an amount sufficient to provide an Isocyanate Index of 70 to 200 with a second reaction mixture consisting of at least one natural polyol in the presence of an ionic liquid, a blowing agent composition consisting of water, an effective amount of a catalyst composition comprising a gelling catalyst and a blowing catalyst, and optionally one of more of a plasticizer, an emulsifier, a bacteriostat, a chain extender, a hydrocarbon blowing agent, an emulsifier, an inorganic compound, a filler, a dye or colorant, an antioxidant, anti-static agent, a UV stabilizer, glycerine, a chain extender and/or cross-linker, and/or a cell-opening agent, for a period of time sufficient to produce a polyurethane foam,
the foam having a density of 0.3 lb/ft 3 to 5 lb/ft 3 (6 Kg/m 3 to 80 Kg/m 3 );
wherein the ionic liquid is used in a concentration from about 5 wt % to about 60 wt % based on the combined weight of the first reaction mixture and the second reaction mixture.
2. The method of claim 1 , wherein the hydrocarbon blowing agent is present in the second reaction mixture.
3. The method of claim 1 , wherein the at least one natural polyol is selected from the group consisting of sucrose, corn syrup, dextrose, fructose, glucose, molasses, and combinations thereof.
4. The method of claim 1 , wherein the filler is present in the second reaction mixture.
5. The method of claim 1 , wherein the colorant is present in the second reaction mixture.
6. The method of claim 1 , wherein the anti-static agent is present in the second reaction mixture.
7. The method of claim 1 , wherein glycerine is present in the second reaction mixture.
8. The method according to claim 1 , wherein the ionic liquid is selected from a choline salt and a choline salt in combination with urea.
9. The method according to claim 1 , wherein water is present in the first reaction mixture from 6 wt % to 26 wt % based on the weight of the at least one natural polyol.
10. The method according to claim 1 , wherein the ionic liquid is present from about 5 wt % to about 25 wt % based on the combined weight of the first reaction mixture and the second reaction mixture.