Nanoclay filled soy‐based polyurethane foam

Polyurethane foam was fabricated from polymeric diphenylmethane diisocyanate (pMDI) and soy‐based polyol. Nanoclay Cloisite 30B was incorporated into the foam systems to improve their thermal stabilities and mechanical properties. Neat polyurethane was used as a control. Soy‐based polyurethane foams with 0.5–3 parts per hundred of polyols by weight (php) of nanoclay were prepared. The distribution of nanoclay in the composites was analyzed by X‐ray diffraction (XRD), and the morphology of the composites was analyzed through scanning electron microscopy (SEM). The thermal properties were evaluated through dynamic mechanical thermal analysis (DMTA). Compression and three‐point bending tests were conducted on the composites. The densities of nanoclay soy‐based polyurethane foams were higher than that of the neat soy‐based polyurethane foam. At a loading of 0.5 php nanoclay, the compressive, flexural strength, and modulus of the soy‐based polyurethane foam were increased by 98%, 26%, 22%, and 65%, respectively, as compared to those of the neat soy‐based polyurethane foam. The storage modulus of the soy‐based polyurethane foam was improved by the incorporation of nanoclay. The glass transition temperature of the foam was increased as the nanoclay loading was increased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Physical Properties of Polyurethanes Produced from Polyols from Seed Oils: II. Foams

Rigid polyurethane (PU) foams were prepared using three North American seed oil starting materials. Polyol with terminal primary hydroxyl groups synthesized from canola oil by ozonolysis and hydrogenation based technology, commercially available soybean based polyol and crude castor oil were reacted with aromatic diphenylmethane diisocyanate to prepare the foams. Their physical and thermal properties were studied and compared using dynamic mechanical analysis and thermogravimetric analysis techniques, and their cellular structures were investigated by scanning electron microscope. The chemical diversity of the starting materials allowed the evaluation of the effect of dangling chain on the properties of the foams. The reactivity of soybean oil-derived polyols and of unrefined crude castor oil were found to be lower than that of the canola based polyol as shown by their processing parameters (cream, rising and gel times) and FTIR. Canola-PU foam demonstrated better compressive properties than Soybean-PU foam but less than Castor-PU foam. The differences in performance were found to be related to the differences in the number and position of OH-groups and dangling chains in the starting materials, and to the differences in cellular structure.     

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     

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.     

Solvent-blown,rigid urethane foams from low cost castor oil-polyol mixtures

The preparation of solvent-blown rigid urethane foams from low cost castor oil-polyol mixtures was investigated. Solutions of triisopropanolamine, and of mixtures of triisopropanolamine and triethanolamine in castor oil, were used as the polyol component of these foams. Foams were prepared by reacting these polyol mixtures, in the presence of catalyst, surfactant, and trichlorofluoromethane, with prepolymers prepared from toluenediisocyanate and certain polyether polyols or mixtures of these polyether polyols with castor oil. The effect of polyol and prepolymer composition and blowing agent concentration on such foam properties as density and compressive strength was investigated. The properties of the castor oil-based foams were comparable to those of foams obtained from more costly polyols. Presented at the Spring Meeting of the American Oil Chemists' Society, St. Louis, Missouri, May 1–3, 1961. A laboratory of the Western Utilization Researchand Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Substituting soybean oil-based polyol into polyurethane flexible foams

Polyurethane (PU) flexible foams were synthesized by substituting a portion of base polyether polyol with soybean oil-derived polyol (SBOP) as well as well-known substituent: crosslinker polyol and styrene acrylonitrile (SAN) copolymer-filled polyol. Increases in compression modulus were observed in all substituted foams and the most substantial increase was found in the 30% SBOP-substituted sample. Scanning electron microscopy (SEM) was used to examine cellular structure, in particular cell size. Polymer phase morphology, i.e., interdomain spacing and microphase separation, was studied using small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM). Hydrogen bonding was investigated via Fourier transform infrared (FTIR) spectroscopy. Thermal and mechanical behaviors of foams were examined using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). Compression properties were tested and compared via a 65% indentation force deflection (IFD) test. It was found that substituting SAN-filled polyol slightly reduced foam cell size and had no effect on polymer phase morphology. Crosslinker and SBOP polyols, on the other hand, had appreciable influence on polymer phase morphology. Crosslinker polyol disrupted hydrogen bonding between hard segments and was mixed with hard domains. SBOP polyol reduced hard domain size and soft domain fraction, and showed a broad distribution of interdomain spacings. Compression modulus increases in foams correlated well with shear modulus by DMA and could be associated with the polymer phase morphology changes.     

Rigid urethane foams from blown castor oils

Solvent-blown rigid urethane foams prepared from a low-cost polyol mixture composed of raw castor oil and triisopropanolamine have been described. Foams with higher compressive strengths can be obtained by substituting oxidized (blown) castor oil for the raw castor oil in formulations of this type. The properties of rigid foams prepared from several commercial blown castor oils are described. The properties of these foams are correlated with the degree of oxidation of the blown oils used, as indicated by their oxygen content, density, viscosity, and refractive index. Removal of acid from blown oils having high acid values has no significant effect on the compressive strength of foams prepared from these oils. When blown castor oil is used instead of raw castor oil, less isocyanate is required to produce a urethane foam of specified density and compressive strength. Presented at the AOCS meeting in Toronto, Canada, 1962. A laboratory of the W. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

The preparation and properties of some urethane foams from castor oil and elaidinized castor oil

Summary The preparation and properties of two series of castor oil urethane foams, one from castor oil and the other from elaidinized castor oil, were investigated. The first series of foams was made from prepolymers containing 60% of castor oil prepared at increasing temperature levels to vary the degree of crosslinking in the final foams. These foams had lower tensile strengths than observed for a previously prepared foam of 60% castor oil and did not show significant differences in water resistance as crosslinking varied. They were increased nearly 100% in compressive strength with increased crosslinking and had very good shrinkage characteristics as values of only 1 to 2% were obtained. A second series of foams was prepared from 50, 60, 70, and 80% of elaidinized castor oil to compare with foams from a similar series from castor oil. This series of foams of 50 to 80% elaidinized castor oil contents was similar in density (1.7 to 6.7 lbs./cu. ft.), had improved shrinkage characteristics (11, 1, 3, and 4%, respectively), showed increased compressive and tensile strengths (up to 12.1 p.s.i. at 50% compression modulus and 34.7 p.s.i. ultimate tensile for the 60% foam formulation), and had better water-resistance properties (411 to 155%vs. 515 to 170% water absorption) than the analogous foams from castor oil. In general, humid aging only slightly affected the values obtained for the foams and was significant in only a few instances,e.g., decreased tensile in the elaidinized castor oil series. Thus increasing crosslinks in the foam apparently did not improve water resistance but did improve shrinkage characteristics in addition to some increased strength properties, as would be anticipated. Foams from elaidinized castor oil, while similar in density and foaming characteristics to analogous foams from castor oil, exhibited less shrinkage and improved water-resistance. Presented at the 50th Annual Meeting of the American Oil Chemists' Society, New Orleans, La., April 20–22, 1959. Ono of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture.     

Solvent-blown rigid urethane foams from castor-based polyols

The preparation of trichlorofluoromethane-blown rigid urethane foams using toluenediisocyanate and castor oil-derived polyols was investigated. The castor-based polyols included castor oil, hydroxylated castor oil, technical glycerol-, penta-erythritol-, and sorbitol monoricinoleates, and N,N-bis(2-hydroxyethyl) ricinoleamide. The last of these yielded the best foams when used as the sole polyol component added to the prepolymer. However better foams were obtained by using, as the polyol component, a mixture of a castor oil-derived polyol and a lower-molecular-weight polyol with a higher hydroxyl content. These polyol mixtures yielded more highly cross-linked polymers and hence foams with higher compressive strengths and less tendency to shrink after foaming. The effect of catalyst, silicone surfactant, and trichlorofluoromethane content was also investigated. An empirical relationship between density and compressive strength in a given foam system was derived. Presented at the fall meeting, American Oil Chemists' Society, New York, October 17–19, 1960. A laboratory of the Western Utilization Research and Development Division. Agricultural Research Service, U.S. Department of Agriculture.     

Cloisite clay‐infused phenolic foam nanocomposites

A sonochemical technique was developed to infuse Cloisite clay nanoparticles into phenolic foam materials. Phenolic resin solution (Part A) was mixed with clay particles, and irradiated using a high intensity ultrasonic liquid processor. In the next step, the modified phenolic resin solution containing clay particles was mixed with Part B (containing phenol sulfonic acid, catalyst) through a high‐speed mechanical stirrer. The reaction mixture was then cast into rectangular molds to make nanophased foam panels. Test coupons were cut precisely from the panels to carry out thermal, morphological, and mechanical characterizations. The as‐prepared foam samples were characterized by scanning electron microscopy (SEM), X‐ray diffraction, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The SEM studies have shown that the particles are well dispersed over the entire volume of the matrix with minimal agglomeration. The foam cells structures are well‐ordered and uniform in size and shape. The TGA and DSC analyses show that the nanophased foams are thermally more stable than the corresponding neat system. Quasistatic compression tests have been carried out for both nanophased and neat foams systems. The test results show that there is a significant increase (approximately in the range of 150–180%) in the compressive strength and modulus of the nanophased foams over the neat system. This improvement in compressive properties has been noted repeatedly for multiple batches and with a minimum of three specimens tested from each batch. Details of the synthesis, thermal and mechanical characterization are presented in this paper. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 308‐314, 2007     

膨胀石墨阻燃蓖麻油磷酸酯聚氨酯保温材料

以蓖麻油和甘油经过酯交换反应生成甘油醇解蓖麻油,然后与双氧水生成环氧醇解蓖麻油,在三苯基膦作催化剂作用下与磷酸二乙酯进行开环反应制备蓖麻油磷酸酯阻燃多元醇。以蓖麻油磷酸酯阻燃多元醇和甘油醇解蓖麻油与膨胀石墨（ＥＧ）和磷酸三乙酯（ＴＥＰ）共混制备了阻燃聚氨酯泡沫,并研究了聚氨酯泡沫的力学性能、阻燃性能和热稳定性。结果表明,蓖麻油磷酸酯阻燃多元醇、ＥＧ提高了聚氨酯泡沫的阻燃性能、热稳定性和力学性能,磷酸二乙酯基团的存在提高了聚氨酯泡沫的阻燃性能,ＥＧ和ＴＥＰ有协同阻燃的作用,使聚氨酯泡沫燃烧时产生更多的炭层,两者共同作用使聚氨酯泡沫的极限氧指数提高到２９．７％。     

蓖麻油聚醚多元醇在聚氨酯软泡中的应用

利用双金属催化剂(DMC)制备了相对分子质量在2000～5600之间的聚氨酯(PU)软泡用蓖麻油聚醚多元醇,并通过发泡实验与常用软泡聚醚多元醇H-330进行了性能比较。结果表明,相对分子质量2000的蓖麻油聚醚多元醇制备的泡沫拉伸强度、伸长率和压陷硬度等均优于H-330聚醚,表明蓖麻油聚醚多元醇完全可以取代普通聚醚多元醇用于普通软泡生产。     

Modification of tung oil–based polyurethane foam by anhydrides and inorganic content through esterification process

In this study, we have reported the synthesis of modified polyol from tung oil. The synthesis involves three steps: first, conversion of tung oil to hydroxylated tung oil by hydroxylation; second, alcoholysis with triethanolamine; and finally, the esterification of polyester polyol when reacted with phthalic anhydride (PA) or maleic anhydride (MA). Boric acid is also introduced into the polyol by chemical modification, which enhances the thermal properties of polyurethane foam (PUF). PUF is formulated by the reaction between polyol and isocyanate. A systematic comparison of flame retardancy and mechanical and thermal properties of modified PUF has been examined. The structural properties of modified polyol were characterized by Fourier transform infrared spectroscopy, proton NMR spectroscopy, and gel permeation chromatography, while the thermal and mechanical properties of the formulated PUF were studied by scanning electron microscopy, limiting oxygen index, differential scanning calorimetry, Izod impact, and flexural and compression strength. Thus PUF prepared from modified polyol with a proper distribution of soft and hard segments possesses better mechanical and thermal properties. The PA‐modified foams show better properties compared to unmodified and MA‐modified foams due to the aromaticity and crosslinking behavior of PA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45786.     

Viscoelastic changes and cell opening of reacting polyurethane foams from soy oil

The modulus development of reacting polyurethane foams from modified soy oil (soy polyol) was studied. The reaction and buildup of rheological properties were monitored using vane geometry in a strain‐controlled rheometer. Normal force exerted on the vanes by the expanding foam was measured as a function of time to study the phenomenon of cell opening. The effect of foam ingredients and process parameters on the modulus development was investigated. The morphology of the cured foam was studied using scanning electron microscope (SEM). Experiments were carried out to elucidate the effect of water and addition of petroleum‐based polyol on the modulus development of the reacting foam and the morphology of the cured product. The effect of frequency and thermal history on the modulus development of the reacting foam was also studied. Ozonolysis of soybean oil was carried out to study the effect of adding OH groups on the modulus development during the foaming reaction. Four stages of modulus development, similar to those observed for synthetic polyol (voranol, Aldrich Chemicals) foams, were observed. Increase in water content led to an earlier stiffening of the polymer and a higher modulus. Addition of voranol in soy polyol reduced the liquid foam plateau and significantly reduced the reaction time. Ozonolysis of soy oil led to an earlier phase separation as compared with foams from soy polyol. The temperature at which the foaming reaction takes place dominated the rate of modulus buildup. Higher texture (urea aggregates) and an increase in the cell size were observed with an increase in water content for soy polyol foams. Addition of voranol increased the number of open cells. Polym. Eng. Sci. 44:1977–1986, 2004. © 2004 Society of Plastics Engineers.     

Rigid polyurethane foams made from high viscosity soy‐polyols

This study investigated the physical properties of water‐blown rigid polyurethane (PU) foams made from VORANOL®490 (petroleum‐based polyether polyol) mixed with 0–50% high viscosity (13,000–31,000 cP at 22°C) soy‐polyols. The density of these foams decreased as the soy‐polyol percentage increased. The compressive strength decreased, decreased and then increased, or remained unchanged and then increased with increasing soy‐polyol percentage depending on the viscosity of the soy‐polyol. Foams made from high viscosity (21,000–31,000 cP) soy‐polyols exhibited similar or superior density‐compressive strength properties to the control foam made from 100% VORNAOL® 490. The thermal conductivity of foams containing soy‐polyols was slightly higher than the control foam. The maximal foaming temperatures of foams slightly decreased with increasing soy‐polyol percentage. Micrographs of foams showed that they had many cells in the shape of sphere or polyhedra. With increasing soy‐polyol percentage, the cell size decreased, and the cell number increased. Based on the analysis of isocyanate content and compressive strength of foams, it was concluded that rigid PU foams could be made by replacing 50% petroleum‐based polyol with a high viscosity soy‐polyol resulting in a 30% reduction in the isocyanate content. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Constitutive modeling of HDPE polymer/clay nanocomposite foams

A constitutive model for tensile behavior of high density polyethylene (HDPE)/clay nanocomposite foams was proposed. The elastic modulus of HDPE/clay nanocomposite was developed using micromechanics theory, and the modulus for foams was obtained by using representative volume element (RVE) concept. In order to describe the tensile behavior of the foams, a constitutive equation obtained from a viscoelastic model was proposed. The constitutive model was expressed in terms of microstructural properties of polymer, and physical properties of the foams. The effects of the material parameters and processing conditions on the foam morphologies and mechanical properties of HDPE/clay nanocomposite foams were investigated. Microcellular closed-cell nanocomposite foams were manufactured with HDPE, where the nanoclay loadings of 0.5, 1.0, and 2.0 wt% were used. The effect of clay loading and foaming conditions on the volume expansion ratio, elastic modulus, tensile strength, and elongation at break was investigated. Except for the elongation at break, the mechanical properties were improved with nanoclay loading. The tensile experimental data of the foams were compared with the prediction by the theoretical model. It was demonstrated that the tensile behaviors of HDPE/clay nanocomposite foams were well described by the constitutive model.     

Effect of vegetable‐based polyols in unimodal glass‐transition polyurethane slabstock viscoelastic foams and some guidance for the control of their structure–property behavior. II

Building on the dynamic mechanical analysis (DMA) characterization of the viscoelastic (VE) foam materials discussed in part I of this two‐part sequential series of articles, in this second part, we provide further information on the general physical properties of many of the same soy polyol and castor‐oil VE foams. In particular, the tensile, tear, elongation, indentation force deflection, support factor, compression set, hysteresis and ball‐rebound (resilience), and density properties are addressed in this article. The air flow and force buildup after compression deformation are also considered. Particular attention is also given to noting the degree of correlation of ball‐rebound behavior to that of the DMA damping data provided in part I. We concluded that when all of the properties of these vegetable‐based VE foams were taken as a whole, they had acceptable structure–property behaviors for VE applications, although certainly, the formulations could undoubtedly be further fine‐tuned for additional optimization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Castor-oil derived nonhalogenated reactive flame-retardant-based polyurethane foams with significant reduced heat release rate

National Fire Protection Association encounters one structural fire every 66 s. Rigid polyurethane foam is one of the principal components used in constructional and household applications. In this work, a reactive flame retardant (FR) was synthesized using a facile one-step thiol–ene reaction by reacting mercaptenized castor oil (MCO) and diethyl allyl phosphonate (DEAP). The obtained MCO–DEAP polyol was used for the preparation of polyurethanes having different weight percentages of phosphorus (P). Addition of FR polyol showed no adverse effect on the cellular structure of the foams and maintained the compressive strength. All the foams showed closed cell content greater than 95%. Horizontal burning test (HBT) was performed before and after the migration test to understand the stability of the FR within the foams. Foams showed no relative weight loss before and after the migration test and maintained equivalent results for HBT. For 1.5 wt % P foams, low extinguishing time of 3 s and weight loss of 4% was observed. The cone calorimeter test showed a reduction in the peak heat release rate from 313 to 158 kW m⁻³, the total heat release from 18 to 8 MJ m⁻², and O₂ consumption from 12 to 6 g. Our results suggest that MCO–DEAP polyol could act as an essential FR for rigid PU foam ensuring fire safety. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47276.     

Preparation and properties of rigid polyurethane foam based on modified castor oil

Castor oil polyol (COP) having a hydroxyl number of 400?mg?KOH/g was prepared through the transesterification reaction of castor oil with glycerol. The effect of reaction temperature on the composition, hydroxyl number and viscosity of the COP products was studied. A series of rigid polyurethane foams were synthesised using the mixtures comprising COP and a petroleum-based polyol with various proportions as polyol component. It was found that the foaming rate, compressive strength and dimensional stability and morphology of resulting foams were dominated by the foam formulation, in a more accurate way, COP content in the polyol mixtures. The combination of expandable graphite and dimethyl methyl phosphonate exhibited stronger flame retardant function which was ascribed to the synergistic effect associated with the simultaneous presence of the two additives. An improvement in thermal stability was observed due to the inclusion of the flame retardants.     

溴化蓖麻油多元醇合成及其制备的阻燃聚氨酯硬泡性能

采用可再生的醇解蓖麻油多元醇为原料,与液溴进行加成反应制备溴化蓖麻油多元醇,通过红外光谱证实发生了溴化反应,并测定了产物粘度、羟值、酸值.通过发泡实验和氧指数、烟密度、水平燃烧等测试手段,考察了溴化蓖麻油基聚氨酯硬泡发泡参数和阻燃性质,并与工业级阻燃荆雅保RB-79制备的聚氨酯硬泡进行比较.结果表明,由溴化蓖麻油多元醇...