Processing hydroxy-carboxylic acids to polymers

Abstract

Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful intermediates and products, such as aliphatic hydroxy-carboxylic acid and hydroxyl-carboxylic acid derivatives. These aliphatic hydroxy-carboxylic acids are, in turn, polymerized. The polymerization is carried out using a thin film evaporator or a thin film polymerization/devolatilization device. Conversion of lactic acid to poly lactic acid is an especially useful product to this process.

1 . A method of processing hydroxy-carboxylic acids, the method comprising:
 producing a hydroxy-carboxylic acid by fermentation of biomass derived sugars;   polymerizing the hydroxy-carboxylic acid to provide a poly hydroxy-carboxylic acid;   adding an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, an aliphatic diol, and/or an aromatic diol to the poly hydroxy-carboxylic acid; and   transferring the poly hydroxy-carboxylic acid to a surface of a thin film evaporator and/or thin film polymerization/devolatilization device;   further polymerizing the poly hydroxy-carboxylic acid by condensing the poly hydroxy-carboxylic acid to provide a hydroxy-carboxylic acid polymer, wherein water is evaporated as it is formed during condensation of the poly hydroxy-carboxylic acid as it traverses the surface of the thin film evaporator and/or thin film polymerization/devolatilization device.   
     
     
         2 . The method of  claim 1 , further comprising polymerizing the hydroxy-carboxylic acid to provide the poly hydroxy-carboxylic acid in the presence of a polymerization catalyst. 
     
     
         3 . The method of  claim 1 , where an extruder is in fluid communication with the thin film evaporator and/or thin film polymerization/devolatilization device and the effluent of the extruder is the poly hydroxy-carboxylic acid polymer, and/or the effluent of the extruder is recycled to the thin film evaporator and/or thin film polymerization/devolatilization device. 
     
     
         4 . The method of  claim 3 , where the extruder is a twin screw extruder. 
     
     
         5 . The method of  claim 1 , wherein the hydroxy-carboxylic acid is selected from the group consisting of glycolic acid, D-lactic acid, L-lactic acid, D-malic acid, L-malic acid, citric acid, L-tartaric acid, D-tartaric acid, beta-hydroxy beta-methylbutyric acid, 4-hydroxy-4-methylpentanoic acid, hydroxybutyric acid, 2-hydroxybutyric acid, beta-hydroxybutyric acid, gamma-hydroxybutyric acid, 3-hydroxyisobutyric acid, 3-hydroxypentanoic acid, 3-hydroxypropionic acid alpha, beta-hydroxyvaleric acid, gamma-hydroxyvaleric acid, and delta-hydroxyvaleric acid, and mixtures thereof. 
     
     
         6 . The method of  claim 5 , wherein the hydroxy-carboxylic acid is D-lactic acid and/or L-lactic acid. 
     
     
         7 . The method of  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a temperature of 100° C. to 260° C. 
     
     
         8 . The method of  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure of less than 0.0001 torr or lower. 
     
     
         9 . The method of  claim 1 , where prior to transferring the poly hydroxy-carboxylic acid to the thin film evaporator and/or thin film polymerization/devolatilization device or during operation of the thin film evaporator and/or thin film polymerization/devolatilization device, a catalyst deactivator and/or stabilizer agent is added. 
     
     
         10 . The method of  claim 1 , where cyclic dimers derived from the hydroxy-carboxylic acid are less than 5 weight percent based on the total mass of the hydroxy-carboxylic acid, poly hydroxy-carboxylic acid, and/or hydroxy-carboxylic acid polymer. 
     
     
         11 . (canceled) 
     
     
         12 . The method of  claim 1 , where the mole ratio of the aliphatic dicarboxylic acid and/or the aromatic dicarboxylic acid to the aliphatic diol and/or the aromatic diol is between 0.95:1 to 1.05:1. 
     
     
         13 . The method of  claim 1 , where the mole ratio of the sum of the aliphatic dicarboxylic acid and/or the aromatic dicarboxylic acid and the aliphatic diol and/or the aromatic diol to the hydroxy-carboxylic acid is 0.1 or less. 
     
     
         14 . The method of  claim 1 , where the mole ratio of the sum of the aliphatic dicarboxylic acid and/or the aromatic dicarboxylic acid and the aliphatic diol and/or the aromatic diol to the hydroxy-carboxylic acid is 0.05 or less. 
     
     
         15 . The method of  claim 2 , where the polymerization catalyst is selected from the group consisting of protonic acids, H 3 PO 4 , H 2 SO 4 , methane sulfonic acid, p-toluene sulfonic acid, polymerically supported sulfonic acid, metals, Mg, Al, Ti, Zn, Sn, metal oxides, TiO 2 , ZnO, GeO 2 , ZrO 2 , SnO, SnO 2 , Sb 2 O 3 , metal halides, ZnCl 2 , SnCl 2 , SnCl 4 , Mn(AcO) 2 , Fe 2 (LA) 3 , Co(AcO) 2 , Ni(AcO) 2 , Cu(OA) 2 , Zn(LA) 2 , Y(OA) 3 , Al(i-PrO) 3 , Ti(BuO) 4 , TiO(acac) 2 , (Bu) 2 SnO, Sn(II)octoate, Li carbonate, Zn diacetate dehydrate, Ti tetraisopropoxide, potassium carbonate, tin powder, solvates thereof, and mixtures thereof. 
     
     
         16 . The method of  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure of less than about 0.001 ton. 
     
     
         17 . The method  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure of less than about 0.01 ton. 
     
     
         18 . The method  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure of less than about 0.1 ton. 
     
     
         19 . The method of  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure of less than about 1 torr. 
     
     
         20 . The method of  claim 1 , further comprising branching or cross linking the poly hydroxy-carboxylic acid. 
     
     
         21 . The method of  claim 20 , wherein the branching or cross linking agent is selected from the group consisting of 5,5′-bis(oxepane-2-one)(bis-ε-caprolactone)), spiro-bis-dimethylene carbonate, peroxides, dicumyl peroxide, benzoyl peroxide, unsaturated alcohols, hydroxyethyl methacrylate, 2-butene-1,4-diol, unsaturated anhydrides, maleic anhydride, saturated epoxides, glycidyl methacrylate, and mixtures thereof. 
     
     
         22 . The method of  claim 1 , wherein the poly hydroxy-carboxylic acid is blended with a second polymer either when the poly hydroxy-carboxylic acid is transferred to the thin film evaporator and/or thin film polymerization/devolatilization device or after the poly hydroxy-carboxylic acid is transferred to the thin film evaporator and/or thin film polymerization/devolatilization device. 
     
     
         23 . The method of  claim 22 , wherein the second polymer is selected from the group consisting of polyglycols, polyvinyl acetate, polyolefins, styrenic resins, polyacetals, poly(meth)acrylates, polycarbonate, polybutylene succinate, polyesters, polyurethanes, natural rubber, polybutadiene, neoprene, silicone, other poly hydroxy carboxylic acids, and mixtures thereof. 
     
     
         24 . The method of  claim 1 , further comprising combining the poly hydroxy-carboxylic acid with a filler. 
     
     
         25 . The method of  claim 24 , wherein the filler is selected from the group consisting of silicates, layered silicates, polymer and organically modified layered silicate, synthetic mica, carbon, carbon fibers, glass fibers, boric acid, talc, montmorillonite, clay, starch, corn starch, wheat starch, cellulose fibers, paper, rayon, non-woven fibers, wood flours, whiskers of potassium titanate, whiskers of aluminum borate, 4,4′-thiodiphenol, glycerol and mixtures thereof. 
     
     
         26 . The method of  claim 1 , further comprising combining the poly hydroxy-carboxylic acid with a dye or pigment. 
     
     
         27 . The method of  claim 26 , wherein the dye or pigment is selected from the group consisting of blue 3, blue 356, brown 1, orange 29, violet 26, violet 93, yellow 42, yellow 54, yellow 8Z and mixtures thereof. 
     
     
         28 . The method of  claim 1 , further comprising combining the poly hydroxy-carboxylic acid with a fragrance. 
     
     
         29 . The method of  claim 28 , wherein the fragrance is selected from the group consisting of wood, evergreen, redwood, peppermint, cherry, strawberry, peach, lime, spearmint, cinnamon, anise, basil, bergamot, black pepper, camphor, chamomile, citronella, eucalyptus, pine, fir, geranium, ginger, grapefruit, jasmine, juniper berry, lavender, lemon, mandarin, marjoram, musk, myrrh, orange, patchouli, rose, rosemary, sage, sandalwood, tea tree, thyme, wintergreen, ylang ylang, vanilla, new car, and mixtures thereof. 
     
     
         30 . The method of  claim 28 , wherein the fragrance is combined with the poly hydroxy-carboxylic acid in an amount between about 0.005% by weight and about 20% by weight. 
     
     
         31 . The method of  claim 1 , wherein converting further includes blending the poly hydroxy-carboxylic acid with a plasticizer. 
     
     
         32 . The method of  claim 31 , wherein the plasticizer is selected from the group consisting of triacetin, tributyl citrate, polyethylene glycol, acetic ester of monoglyceride, diethyl bishydroxymethyl malonate and mixtures thereof. 
     
     
         33 . The method of  claim 9 , where the catalyst deactivator and/or stabilizing agent is selected from the group consisting of anhydrides, phosphites, polycarboxylic acids, polyamines, silica, functionalized silica, alumina, aluminosilicates, clays, functionalized clays and mixtures thereof. 
     
     
         34 . The method of  claim 33 , where the polycarboxylic acid is a poly methacrylic acid. 
     
     
         35 . The method of  claim 11 , further comprising removing the deactivated/stabilized catalyst prior to, during or after operation of the thin film evaporator and/or thin film polymerization/devolatilization device. 
     
     
         36 . The method of  claim 35 , comprising removing the deactivated/stabilized catalyst by a filtration device. 
     
     
         37 . The method of  claim 36 , where the filtration device is in fluid communication with the thin film evaporator and/or the polymerization/devolatilization device. 
     
     
         38 . The method of  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure between about 0.0001 torr and about 100 torr. 
     
     
         39 . The method of  claim 1 , where at least a part of the thin film evaporator and/or thin film polymerization/devolatilization device operates at a pressure between about 0.001 torr and about 50 torr. 
     
     
         40 . (canceled)