A series of polyols was prepared from epoxidized tallow, by reaction with trimethylolpropane in refluxing toluene, sequentially under basic and acidic catalysis. In preliminary experiments, under catalysis by sodium methoxide alone, the trimethylolpropane reacted rapidly with glyceride linkages and very slowly with oxirane groups. Under catalysis by p‐toluenesulfonic acid alone, oxirane was rapidly consumed. Polyols were prepared by the following sequences: (A) reaction under acidic followed by basic catalysis; (B) reaction under basic followed by acidic catalysis; (C) reaction under basic catalysis followed by further treatment with HBr gas to introduce fire retardance; (D) treatment of whole tallow first with trimethylolpropane under basic conditions and secondly with bromine; (E) reaction of epoxidized tallow with diethanolamine under basic catalysis; and (F) treatment of epoxidized tallow first with trimethylolpropane under acidic conditions and then with diethanolamine under basic catalysis. The polyols described were adjusted to equivalent weights of 100 and 120 with added triisopropanolamine and treated with a polymeric isocyanate to give rigid foams. Densities ranged from 1.5–1.8 lb/ft3. Open cell content, for foams made at the equivalent wt of 100, ranged from 14–21%; at the equivalent wt of 120, from 17–27%. Compressive strengths ranged from 14–23 psi, being lower than those of the best previous epoxidized tallow‐trimethylolpropane products.
Improved properties of fire retardant urethane foams prepared from hypobrominated lard and tallow have been obtained by purification of the polyols prior to their use. Hypobromination was carried out by epoxidation of the glycerides followed by treatment with gaseous HBr. The crude derivatives were extracted with acetone and separated from unreacted saturates at 5 C. One step hypochlorination of glycerides by use of acidified sodium hypochlorite has been carried out, and subsequent purification of the polyols led to minor foam property improvement. Fire retardant foams have also been prepared from soybean oil and monoolein using both of these general methods, although the acetone extraction step could be omitted.
Liquid polyols have been prepared from epoxidized glyceryl trioleate, glyceryl monooleate, lard oil, neatsfoot oil, and soybean oil by hydration with 24% fluoboric acid. Upon adjustment of the equivalent weight to 100 with triisopropanolamine, the polyols were foamed by reaction with a prepolymer made from oxypropylated sorbitol and tolylene diisocyanate. The resulting rigid foams had densities between 1.66 and 2.34 lbs/ft 3 and compressive strengths ranging from 23 to 39 psi (10% compression).The same polyols were used in one-step systems with PAPI as the isoeyanate. In general, foam properties were comparable with those obtained from the prepolymer systems.
Intrinsic viscosity-number average molecular weight relationships have been measured, at 30C in benzene, for poly(n-oetadecyl acrylate) as [~] = 2.72 • 10 -4 Mn 063s and for poly(N-n-octadccylaerylamide) as [7] = 0.82 • 10 -4 M~ ~ Whole polymers of various molecular weights were prepared in benzene solution at 65C with dodecyl mercaptan as primary regulator. By the use of these parameters, the molecular weight of such polymers and their homologs may now be measured by simple solution-viscosity determinations.In the expression 1/Xn = 1/Xno + Cs IS]/[M] (relating degrees of polymerization X, to the mereaptan/monomer ratio), intercept 1/Xno and apparent transfer constant Cs for n-octadeey] acrylate were 6.28 • 10 a and 0.68; for N-n-octadecylacrylamide 1.10 • 10 ~ and 0.62 respectively. These parameters permit preparation of homopolymers of chosen molecular weight.
Polyols of higher hydroxyl content than previously obtained from tallow were prepared for use in urethane foams. Epoxidized tallow was caused to react with trimethylolpropane with catalysis by ptoluenesulfonic acid (2%). Reaction at 120 C in toluene gave best results. Alcoholysis occurred both at oxirane and at glyceride linkages, the latter reaction conferring hydroxyl functionality even on nonepoxidized glyceride units. Hydroxyl content of polyol products increased with the functional ratio of the reaction mixture, that is, the molar ratio of OH available from trimethylolpropane to oxirane plus ester from tallow. To provide fire retardant polyols, epoxidized tallow was caused to react with trimethylolpropane and gaseous HBr, best at 80 C in benzene. Examined by thin layer chromatography, the polyols showed polarities in the range of monoand diglycerides.
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