Bio-Based Polyurethanes

Abstract

Polyurethane foams which are highly flame resistant 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, a polyisocyanate and water in the presence of a suitable polyurethane forming catalyst and a non-halogenated flame retardant, and optionally one or more components such as surfactants and/or emulsifiers. The resultant polyurethane foam has 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 exhibits a high degree of fire and burn resistance, as exhibited by the flame spread index, flash over resistance determination, and the smoke spread values.

1 . A flame-retardant polyurethane foam comprising:
 a first reaction mixture comprising at least one polyisocyanate; and   a second reaction mixture comprising:
 a natural polyol wherein substantially all of the hydroxyl groups on the polyol are free; 
 an isocyanate; 
 a non-halogenated flame retardant; 
 a surfactant; 
 an aqueous blowing agent; and 
 a polyurethane producing catalyst. 
   
     
     
         2 . The polyurethane foam according to  claim 1 , wherein the natural polyol is selected from the group consisting of sucrose, fructose, glucose, xylose, corn syrup, dextrose, and molasses. 
     
     
         3 . The polyurethane foam according to  claim 1 , wherein the non-halogenated flame retardant is an inorganic hydroxide or hydrate. 
     
     
         3 a. (canceled) 
     
     
         4 . The polyurethane foam according to  claim 1 , wherein the non-halogenated flame retardant is a phosphate compound. 
     
     
         4 a. (canceled) 
     
     
         5 . The polyurethane foam according to  claim 1 , further comprising one or more of an emulsifier, a surfactant, or a biocide. 
     
     
         6 . The polyurethane foam according to  claim 1 , having a density ranging from about 0.3 lb/ft 3  to about 5.0 lb/ft 3 , and exhibits a percent modern carbon (pMC) value of ranging from about 10% to about 50% as determined by ASTM-D6866-11. 
     
     
         7 . The polyurethane foam according to  claim 1 , wherein the foam product has a bio-based content ranging from about 15% to about 30%, as determined by ASTM D6866-11. 
     
     
         8 . A method of making a flame-retardant polyurethane foam comprising:
 a. admixing an untreated natural polyol in which substantially all of the hydroxyl groups are free, a surfactant, polyurethane forming catalysts, and water to form a first aqueous solution,   b. adding to the first aqueous solution mixture a second solution containing a polyisocyanate; and   c. allowing the mixture to foam.   
     
     
         9 . The method of  claim 8 , further comprising the addition of a non-halogenated flame retardant or plasticizer to the first aqueous solution, the second aqueous solution, or both solutions. 
     
     
         10 . The method of  claim 9 , wherein the non-halogenated flame retardant or plasticizer is added to both the first solution and the second solution. 
     
     
         11 . The method of  claim 8  wherein a halogenated or non-halogen containing blowing agent is added to the natural polyol solution. 
     
     
         12 . The method of  claim 8 , further comprising adding an emulsifier to the first aqueous solution. 
     
     
         13 . A method for preparing a water-blown, low density, polyurethane foam, the method which comprises:
 contacting at least one polyisocyanate having an Isocyanate Index of 10 to 500 with at least one natural polyol in the presence of a blowing agent composition comprising at least 0.1 wt % water and an effective amount of a catalyst composition comprising a gelling catalyst and a blowing catalyst for a period of time sufficient to produce a polyurethane foam,   the foam having a density of 0.3 lb/ft 3  to 5 1 lb/ft 3  (6 Kg/m 3  to 80 Kg/m 3 ).   
     
     
         14 . The method of  claim 13 , further comprising the addition of a hydrofluorocarbon, hydrofluoro (chloro) olefin, or hydrocarbon blowing agent. 
     
     
         15 . The method of  claim 13 , further comprising adding a structure or function altering chemical selected from the group consisting of chain extenders, emulsifiers, inorganic compounds, polyols, and combinations thereof. 
     
     
         16 . The method of  claim 13 , wherein the natural polyol is selected from the group consisting of sucrose, corn syrup, dextrose, fructose, glucose, molasses, and combinations thereof. 
     
     
         17 . The method of  claim 13 , further comprising adding a filler. 
     
     
         18 . The method of  claim 13 , further comprising adding a colorant. 
     
     
         19 . The method of  claim 13 , further comprising adding an anti-anti-scorching agent. 
     
     
         20 . The method of  claim 13 , further comprising the addition of glycerine. 
     
     
         21 . The polyurethane foam according of  claim 3 , wherein the non-halogenated flame retardant is an aluminum, barium, calcium, copper, iron, magnesium, nickel, or zinc hydroxide or hydrate. 
     
     
         22 . The polyurethane foam according to  claim 4 , wherein the non-halogenated flame retardant is tris (2-monochloroisopropyl) phosphate.