Synthesis of Transesterified Palm Olein‐Based Polyol and Rigid Polyurethanes from this Polyol

Transesterification of palm olein with glycerol can increase the functionality by introducing additional hydroxyl groups to the triglyceride structure, an advantage compared to using palm olein directly as feedstock for producing palm‐based polyol. The objective of this study was to synthesize transesterified palm olein‐based polyol via a three‐step reaction: (1) transesterification of palm olein, (2) epoxidation and (3) epoxide ring opening. Transesterification of palm olein yielded approximately 78 % monoglyceride and has an hydroxyl value of approximately 164 mg KOH g^?1. The effect of formic acid and hydrogen peroxide concentrations on the epoxidation reaction was studied. The relationships between epoxide ring‐opening reaction time and residual oxirane oxygen content and hydroxyl value were monitored. The synthesized transesterified palm olein‐based polyol has hydroxyl value between 300 and 330 mg KOH g^?1 and average molecular weight between 1,000 and 1,100 Da. On the basis of the hydroxyl value and average molecular weight of the polyol, the transesterified palm olein‐based polyol is suitable for producing rigid polyurethane foam, which can be designed to exhibit desirable properties. Rigid polyurethane foams were synthesized by substituting a portion of petroleum‐based polyol with the transesterified palm olein‐based polyol. It was observed that by increasing the amount of transesterified palm olein‐based polyol, the core density and compressive strength were reduced but at the same time the insulation properties of the rigid polyurethane foam were improved.     

Physical properties of water‐blown rigid polyurethane foams containing epoxidized soybean oil in different isocyanate indices

To explore the potential of isocyanate usage reduction, water‐blown rigid polyurethane foams were made by replacing 0, 20, and 50% of Voranoll® 490 in the B‐side of the foam formulation by epoxidized soybean oil (ESBO) with an isocyanate index ranging from 50 to 110. The compressive strength, density, and thermal conductivity of foams were measured. The foam surface temperature was monitored before and throughout the foaming reaction as an indirect indication of the foaming temperature. Increasing ESBO replacement and/or decreasing isocyanate index decreased the foam's compressive strength. The density of the foam decreased while decreasing the isocyanate index to 60. Further decrease in isocyanate index resulted in foam shrinkage causing a sharp increase in the foam density. The thermal conductivity of foams increased while decreasing the isocyanate index and increasing the ESBO replacement. Mathematical models for predicting rigid polyurethane foam density, compressive strength, and thermal conductivity were established and validated. Similar to compressive strength, the foaming temperature decreased while decreasing the isocyanate index and increasing the ESBO replacement. Because of the lower reactivity of ESBO with isocyanate, the rate of foaming temperature decrease with decreasing isocyanate index was in the order of 0% > 20% > 50% ESBO replacement. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Development of a rigid polyurethane foam from palm oil

The reactions between polymeric diphenyl methane diisocyanate (polymeric MDI) and conventional polyols to produce foamed polyurethane products are well documented and published. Current polyurethane foams are predominantly produced from these reactions whereby the polyol components are usually obtained from petrochemical processes. This article describes a new development in polyurethane foam technology whereby a renewable source of polyol derived from refined–bleached–deodorized (RBD) palm oil is used to produce polyurethane foams. Using very basic foam formulation, rigid polyurethane foams were produced with carbon dioxide as the blowing agent generated from the reaction between excess polymeric MDI with water. The foams produced from this derivatized RBD palm oil have densities in excess of 200 kg/m³ and with compression strengths greater than 1 MPa. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 509–515, 1998     

Water-blown rigid and flexible polyurethane foams containing epoxidized soybean oil triglycerides

Both rigid and flexible water-blown polyurethane foams were made by replacing 0–50% of Voranol® 490 for rigid foams and Voranol® 4701 for flexible foams in the B-side of foam formulation by epoxidized soybean oil. For rigid water-blown polyurethane foams, density, compressive strength, and thermal conductivity were measured. Although there were no significant changes in density, compressive strength decreased and thermal conductivity decreased first and then increased with increasing epoxidized soybean oil. For flexible water-blown polyurethane foams, density, 50% compression force deflection, 50% constant force deflection, and resilience of foams were measured. Density decreased first and then increased, no changes in 50% compression force deflection first and then increased, increasing 50% constant force deflection, and decreasing resilience with increase in epoxidized soybean oil. It appears that up to 20% of Voranol® 490 could be replaced by epoxidized soybean oil in rigid polyurethane foams. When replacing up to 20% of Voranol® 4701 by epoxidized soybean oil in flexible polyurethane foams, density and 50% compression deflection properties were similar or better than control, but resilience and 50% constant deflection compression properties were inferior. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Physical properties of water‐blown rigid polyurethane foams from vegetable oil‐based polyols

Fifty vegetable oil‐based polyols were characterized in terms of their hydroxyl number and their potential of replacing up to 50% of the petroleum‐based polyol in waterborne rigid polyurethane foam applications was evaluated. Polyurethane foams were prepared by reacting isocyanates with polyols containing 50% of vegetable oil‐based polyols and 50% of petroleum‐based polyol and their thermal conductivity, density, and compressive strength were determined. The vegetable oil‐based polyols included epoxidized soybean oil reacted with acetol, commercial soybean oil polyols (soyoils), polyols derived from epoxidized soybean oil and diglycerides, etc. Most of the foams made with polyols containing 50% of vegetable oil‐based polyols were inferior to foams made from 100% petroleum‐based polyol. However, foams made with polyols containing 50% hydroxy soybean oil, epoxidized soybean oil reacted with acetol, and oxidized epoxidized diglyceride of soybean oil not only had superior thermal conductivity, but also better density and compressive strength properties than had foams made from 100% petroleum polyol. Although the epoxidized soybean oil did not have any hydroxyl functional group to react with isocyanate, when used in 50 : 50 blend with the petroleum‐based polyol the resulting polyurethane foams had density versus compressive properties similar to polyurethane foams made from 100% petroleum‐based polyol. The density and compressive strength of foams were affected by the hydroxyl number of polyols, but the thermal conductivity of foams was not. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Polymerization of allyl esters derived from long-chain fatty acids and palm olein

Allyl esters of palm olein, palmitic, and oleic acids were synthesized by transesterification and esterification methods using KOH and absolute H₂SO₄ as catalysts, respectively. Three allyl esters, namely, allyl palmitate, allyl epoxystearate, and epoxidized allyl ester of palm olein, were successfully polymerized in the presence of t-butyl perbenzoate at 120°C to obtain oligomers with the average number of backbone atoms approximately equal to the number of skeletal atoms of the long-dangling side chains. The kinetic data of polymerization were conformed to the rate equation proposed by other workers. No oxirane cleavage was detected during the chain reaction. The melting behavior of these comb-shaped polymers was compared with that of their respective allylic monomers. The polymer of epoxidized allyl ester of palm olein exhibits a glass transition temperature at 204.4 K. The critical molecular weights of the polymers of allyl esters investigated are predicted to be not lower than 10⁴.     

Rigid interpenetrating polymer network foams prepared from a rosin-based polyurethane and an epoxy resin

A series of rigid interpenetrating polymer network (IPN) foams, based on a rosin-based polyurethane and an epoxy resin, were prepared by a simultaneous polymerization technique. The changes in the chemical structure, dynamic mechanical properties, and morphology of the rigid IPN foams were investigated by Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical thermal analysis, and scanning electron microscopy. The FTIR analysis showed clearly that the cure rate of the rosin-based rigid polyurethane foam and the epoxy resin were different and, as a result, these two networks formed sequentially in the final rigid IPN foams. All of the rigid IPN foams exhibited a single, broad glass transition that shifted to lower temperature as the epoxy resin content increased. The experimental composition dependence of T_g's of the rigid IPN foams showed slight positive deviation from the Fox equation for homogeneous polymer systems. No phase separation was observed from the scanning electron microscopy investigation. It could be concluded that these two component networks were compatible in the final rigid IPN foams. This compatibility could be attributed to a graft structure in the polyurethane and the epoxy resin networks arising from the reaction of the hydroxyl groups of the epoxy resin with the isocyanate groups of MDI, and from the reaction of the hydroxyl groups of the polyols with the epoxide groups of the epoxy resin, as suggested by FTIR analysis. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 271–281, 1998     

Synthesis of Palm Oil-Based Diethanolamides

In this work, Epoxidized Palm Olein (EPO_o) was blended with Refined Bleached Deodorized Palm Kernel Olein (RBDPKO_o) in a range of 10–100% (w/w) to react with diethanolamine (DEA) with a 1:3 molar ratio to produce diethanolamides that retained some epoxides. The epoxidized diethanolamides are proposed as a new type of vegetable oil derived polyols for rigid polyurethane. The optimal reaction temperature is 110 °C for 5 h. In addition, the optimal amount of starting materials were determined to be 40% (w/w) of EPO_o blended with 60% (w/w) of RBDPKO_o. The diethanolamides appeared as non-viscous liquid at room temperature with a viscosity of 990.08 cP at 25 °C and 427.09 cP at 40 °C, a cloud point of 21 °C, a pour point of 12 °C and 0.78% of retained oxirane oxygen contents (OOC). The hydroxyl and the amine values of the diethanolamides were determined as 351.85 mg KOH/g sample and 4.5 mg KOH/g sample, respectively. In addition, chemical elucidation of the diethanolamides with functional epoxides was carried out using Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry (GCMS) for the purpose of process development and quality control.     

Formation and characterization of polyurethane—vermiculite clay nanocomposite foams

Nanocomposites of rigid polyurethane foam with unmodified vermiculite clay are synthesized. The clay is dispersed either in polyol or isocyanate before blending. The viscosity of the polyol is found to increase slightly on the addition of clay up to 5 pphp (parts per hundred parts of polyol by weight). The gel time and rise time are significantly reduced by the addition of clay, indicating that the clay acts as a heterogeneous catalyst for the foaming and polymerization reactions. X‐ray diffraction and transmission electron microscopy of the polyurethane composite foams indicate that the clay is partially exfoliated in the polymer matrix. The clay is found to induce gas bubble nucleation resulting in smaller cells with a narrower size distribution in the cured foam. The closed cell content of the clay nanocomposite foams increases slightly with clay concentration. The mechanical properties are found to be the best at 2.3 wt% of clay when the clay is dispersed in the isocyanate; the compressive strength and modulus normalized to a density of 40 kg/m³ are 40% and 34% higher than the foam without clay, respectively. The thermal conductivity is found to be 10% lower than the foam without clay. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Synthesis of palm oil‐based polyester polyol for polyurethane adhesive production

Palm oil‐based polyester polyol is synthesized by ring opening reaction on epoxidized palm olein by phthalic acid. The reaction is carried out in a solvent free and noncatalyzed condition with the optimal reaction condition at 175°C for 5 h reaction time. The physical state of the product is a clear bright yellowish liquid with low viscosity value of 5700–6700 cP at 25°C and pour point of 15°C. The chemical structure and molecular weight of the polyester polyol were characterized by FTIR, ¹H‐NMR, ¹³C‐NMR, and GPC. The optimal polyol with molecular weight of 36,308 dalton and hydroxyl value of 78.17 mg KOH/g sample was reacted with polymeric 4,4′‐methylene diphenyl diisocyanate (pMDI) at isocyanate index of 1.3 to produce polyurethane adhesive. The lap shear strength of the polyurethane adhesive showed two times higher than the commercial wood adhesives. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39967.     

Mechanical Properties and Flame Retardancy of Rigid Polyurethane Foams Containing SiO2 Nanospheres/Graphene Oxide Hybrid and Dimethyl Methylphosphonate

Halogen-free flame-retardant rigid polyurethane foams were prepared using the combination of SiO₂ nanospheres/graphene oxide hybrid and a phosphorus-containing flame retardant, dimethyl methylphosphonate. The flame retardancy, mechanical, and thermal properties of flame-retardant rigid polyurethane foams containing dimethyl methylphosphonate and SiO₂ nanospheres/graphene oxide were investigated. The results demonstrated that the combination of dimethyl methylphosphonate and SiO₂ nanospheres/graphene oxide enhanced flame retardant and mechanical properties of rigid polyurethane foam greatly compared with pure rigid polyurethane foam and dimethyl methylphosphonate-modified foam. Morphological study indicated that the partial substitution of dimethyl methylphosphonate with SiO₂ nanospheres/graphene oxide led to smaller cell sizes and more uniform cell sizes of dimethyl methylphosphonate-modified rigid polyurethane foams.     

Polymer morphology of CO2-blown rigid polyurethane foams: Its fractal nature

Small-angle x-ray scatting (SAXES) and transmission electron microscopy (TEM) have been applied to study polymer morphologies of CO₂,-blown rigid polyurethane foam samples of varying isocyanate index. The results are consistent with an irregular (meso) phase segregated structure with phase boundaries showing fractal symmetry. Phase segregation persists, througtout the index range, althougt the interfacial surfaces tends to smooothen with increasing isocyanate index to evetually results in a significant degree of energetic ‘sharing’ across the4 phase boundary. The latter can satisfactorily be explained by a free volume double layer (PVDL) model. Mechanistically. Fractal symmetry was attributed to the competition between crossliking and phase segregation tendencies in rigid PU foam polymers. The resulting frozen-in morphology represents an early stage of the development towards a more regular spinodal phase segregation, as occurring in polyuethane foam systems of lower crosslink density (e.g. flexible foams). © 1994 John Wiley & Sons, Inc.     

Synthesis and in situ foaming of biodegradable malonic acid ESO polymers

In this study, biodegradable rigid cellular materials were synthesized from the reaction of malonic acid with epoxidized soybean oil. Malonic acid reacts with two epoxy groups to give a network polymer. In the course of this reaction, initially formed malonic acid monoester (MAME) can decarboxylate and produce CO₂, which acts as the blowing agent leading to in situ foaming of the polymer. Epoxide addition and decarboxylation reactions of MAME occur competitively and simultaneously and by controlling their relative rates, foams of controlled density were produced. ¹H NMR spectrum of the synthesized foams showed that increasing the temperature increases the rate of decarboxylation reaction of MAME and decreases crosslink density leading to softer and lower density foams. Addition of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a catalyst also increases the rate of decarboxylation. Load deflection curves of the cellular materials showed that decreasing the temperature and addition of DABCO increase compressive modulus of samples. Cell morphology was studied by microscopic images of foam samples that showed that foam samples have a closed cell structure and a wide distribution of cell volume. Soil burial test was done to determine rate of biodegradation of foam samples. A half‐life of 815 days showed that foam samples are highly biodegradable. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Rigid polyurethane foams from diethanolamides of carboxylated oils and fatty acids

New polyols of high hydroxyl content and reactivity were made from linseed and soybean oils and acids by catalytic carboxylation followed by reaction with diethanolamine. Urethane foams made with these diethanolamides were stronger than those made with castor oil at equivalent polyol wt. Because of their higher hydroxyl content, a larger amount of diethanolamides could be incorporated in foam formulations than is possible with castor oil. The rigid urethane foams prepared with the new polyols meet the requirements of commercial products with respect to density, compressive strength, and dimensional stability. National Flaxseed Processors Association Fellow, 1969–1973. Present address: Avery Products, Technical Center, 325 North Altadena Dr., Pasadena, CA 91107.     

Influence of the composition of rosin-based rigid polyurethane foams on their thermal stability

A series of rosin-based rigid polyurethane foams of different composition were synthesized directly from chemically modified gum rosin. The effect of the composition of these rosin-based rigid polyurethane foams on their thermal stability and compression strength was measured. It was shown that the onset temperature of weight loss and the dimensional stability at high temperature increased with increase of the molar ratio of NCO/OH. The TGA data further confirmed that the second stage weight loss in the two-stage weight loss process of these polyurethane foams was governed by thermal degradation of the isocyanate component. Although density had no significant influence on the TGA curves of the rosin-based rigid polyurethane foams, it had great influence on the dimensional stability at high temperature and compression strength of the foams. It has been shown that the inclusion of rosin in rigid polyurethane foams increases the strength and thermal stability compared with that of polyether-based ones. © 1996 John Wiley & Sons, Inc.     

A review of the literature on the gaseous products and toxicity generated from the pyrolysis and combustion of rigid polyurethane foams

The literature on rigid polyurethane foam has been reviewed with an emphasis on the gaseous products generated under various thermal decomposition conditions and the toxicity of those products. This review is limited to publications in English through 1984. Carbon monoxide (CO) and hydrogen cyanide (HCN) were the predominant toxicants found among more than a hundred other gaseous products. The generation of CO and HCN was found to increase with increasing combustion products from various rigid polyurethane foams. Lethality, incapacitation, physiological and biochemical parameters were employ as biological end points. In general, the combustion products generated from rigid polyurethane foam in the flaming mode appear from to be more toxic than those produced in the non-flaming mode. The LC₅₀ values for 30-min exposures ranged from 10 to 17 mg l^?1 in the flaming mode and were greater then 34 mg l^?1 in the non-flaming mode. With the exception of one case, in which a reactive type phosphorus containing fire retardant was used, the addition of fire retardants to rigid polyurethane foams does not appear to generate unusual toxic combustion products.     

A comparative study of polyurethane foam by substituting LBA using green polyurethane foam CFA-1

Polyurethane foams are well-known optimal thermal-insulating materials, which have good thermal insulation performance, high strength, and lightweight properties. Here, we describe a chlorine-free and fluorine-free polyurethane chemical foaming agent (CFA-1) that can react with isocyanate to release CO₂ gas and foam polyurethane. We systematically studied its application performance in the field of polyurethane spraying by substituting the current most advanced and environment-friendly physical foaming agent 1-chloro-3,3,3-trifluoroprop-1-ene in different proportions. The results show that highly competitive mechanical properties lead to economical, environment-friendly, and efficient features. The lower thermal conductivity, more compact and smaller bubble structure, and excellent compression strength were achieved by tuning the proportion of CFA-1 from 20% to 60%. Thus, a promising material system was established for the development of the rigid polyurethane foam industry.     

Urethane foams from animal fats: IX. Polyols based upon tallow and trimethylolpropane; preparation under acidic and basic catalysis

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. Presented at the AOCS Meeting, Mexico City, Mexico, May 1974. ARS, USDA.     

改性条件对阻燃型硬质聚氨酯泡沫塑料性能的影响

选择阻燃剂三聚氰胺和甲基磷酸二甲酯（DMMP）对硬质聚氨酯泡沫塑料进行阻燃改性,研究了异氰酸酯指数、水、三聚氰胺以及DMMP添加量对硬质聚氨酯泡沫塑料阻燃性能和拉伸强度的影响主次顺序。结果表明,添加三聚氰胺和DMMP可以提高硬质聚氨酯泡沫塑料的阻燃性能,当三聚氰胺的添加量为25份、DMMP的添加量为25份、异氰酸酯指数为1.15、水添加量为1.5份时,硬质聚氨酯泡沫塑料的综合性能最佳。     

Investigation on flammability of rigid polyurethane foam‐mineral fillers composite

This study investigates the incorporation of castor oil–based rigid polyurethane foam with mineral fillers feldspar or kaolinite clay in order to enhance the mechanical, thermal, and flame retardant properties. Influence of mineral fillers on the mechanical strength was characterized by compressive strength and flexural strength measurement. Thermogravimetric analysis (TGA) was performed to diagnose the changes in thermal properties, while cone calorimeter test was performed to ascertain the flame retardancy of the mineral filler–incorporated rigid polyurethane foam composites. Results showed that the foams incorporated with mineral filler demonstrated up to 182% increase in compressive strength and 351% increase in flexural strength. Thermal stability of these composite foams was also found to be enhanced on the incorporation of kaolinite clay filler with an increase in 5% weight loss temperature (T_5%) from 192°C to 260°C. Furthermore, peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) were also found to decreased on the incorporation of mineral filler in the rigid polyurethane foam. So mineral fillers are ascertained as a potential filler to enhance the mechanical, thermal, and flame retardant behaviors of bio‐based rigid polyurethane foam composites.