Jet-cooked starch-oil composite in polyurethane foams

A new jet-cooked starch—oil composite has been blended with a polyester polyol and then reacted with isocyanate to give a polyurethane foam. Infrared spectroscopy and microscopy have been used to examine the resultant products. Infrared spectra have shown the products contain the urethane structures and light and electron microscopy have shown the differences in the cell wall structures and networks of the foams when compared to the control foams. Inclusion of the starch—oil composite in the formulation resulted in increased viscosity of the reaction mixture as well as a more irregular cellular structure and a rougher texture of the cured foam. Larger cells were more abundant and there was more evidence of tearing during expansion. The scanning electron photomicrographs show the open-cell structure of both the control and blended foams and their reticular network, which is more uniform in the control. This examination provides insight into the foaming process and provides information to make the necessary adjustments for acquiring the desired polymeric product. Incorporation of the starch—oil composite in polyurethane foams provides a new dimension of possibilities for enhancing their physical, functional, and environmental properties. © 1997 John Wiley & Sons, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

J Appl Polym Sci 64: 1355–1361, 1997     

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     

Rigid Polyurethane Foam Production from Palm Oil-Based Epoxidized Diethanolamides

A new type of rigid polyurethane foam was produced by incorporating oxazolidone heterocyclic rings on to polyurethane backbones. Epoxidized diethanolamides were synthesized by reacting palm oil blends of epoxidized palm olein and refined bleached deodorized palm kernel olein with diethanolamine to produce rigid polyurethane foams. Epoxides, retained in the diethanolamides, reacted with isocyanate during foam production in the presence of AlCl₃–THF complex catalyst to form oxazolidone linkages in the polyurethane network. The carbonyl stretch of oxazolidone was identified at 1,750 cm⁻¹ through Fourier Transform Infra Red analysis. Chemical modifications of the polyurethane network also improved the thermal and mechanical properties of the foams. In addition, isocyanate index 1.4 was determined to be the most suitable in the production of foams from this newly synthesized epoxidized diethanolamides.     

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     

Recycling of polyurethane and polyisocyanurate foam

Heating of isocyanate derived foams with glycol mixtures is a simple and economically attractive recycling process. The process is emission free, not sensitive to varying product mixes and the obtained polyols can be completely reused in the manufacture of rigid polyurethane or polyisocyanurate foam.     

淀粉和乙二醇葡萄糖苷改性聚氨酯泡沫塑料的制备

通过添加淀粉和由淀粉合成的乙二醇葡萄糖苷共混改性,以改善硬质聚氨酯泡沫塑料的物理力学性能,研究了聚醚(PAO)、二苯甲烷二异氰酸酯(MDI)和复合催化剂的配比及淀粉和糖苷的加入量对改性硬质聚氨酯泡沫塑料的影响,并对发泡工艺进行了改进。正交试验结果表明:制备改性硬质聚氨酯泡沫塑料的最佳质量配比为PAO∶MDI∶复合催化剂=100∶125∶2,当淀粉加入量为PAO质量的45%,乙二醇葡萄糖苷加入量为PAO质量的40%时,制备的改性硬质聚氨酯泡沫塑料的压缩强度提高了38%,密度提高了47%,而且具有较好的弹性和耐水性。     

蒸馏水含量对三明治结构硬质聚氨酯泡沫性能的影响

采用异氰酸酯、聚酯多元醇、发泡剂（水）等原料通过一体发泡成型技术制备出一种新型的三明治泡沫夹心复合材料。利用热重分析、扫描电子显微镜等对不同水含量（质量分数分别为0、0.5 %和1.0 %）的硬质聚氨酯泡沫材料的泡孔直径、密度、热导率、压缩性能、三点弯曲和热力学性能等做了研究,进而确定提高硬质聚氨酯性能的最佳工艺。结果表明,随着水含量的增加,硬质聚氨酯泡沫材料泡孔直径增大,密度变小,热导率降低,保温性能提高,而压缩性能和三点弯曲却呈下降趋势;综合考虑硬质聚氨酯泡沫材料泡孔结构和良好的保温隔热及弯曲等力学性能,其最佳含水量为0.5 %。     

Rigid polyurethane foams based on soybean oil

Both HCFC‐ and pentane‐blown rigid polyurethane foams have been prepared from polyols derived from soybean oil. The effect of formulation variables on foam properties was studied by altering the types and amounts of catalyst, surfactant, water, crosslinker, blowing agent, and isocyanate, respectively. While compressive strength of the soy foams is optimal at 2 pph of surfactant B‐8404, it increases with increasing the amount of water, glycerin, and isocyanate. It also increases linearly with foam density. These foams were found to have comparable mechanical and thermoinsulating properties to foams of petrochemical origin. A comparison in the thermal and thermo‐oxidative behaviors of soy‐ and PPO‐based foams revealed that the former is more stable toward both thermal degradation and thermal oxidation. The lack of ether linkages in the soy‐based rather than in PPO‐based polyols is thought to be the origin of improved thermal and thermo‐oxidative stabilities of soy‐based foams. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 467–473, 2000     

Polyurethane Composite Foams in High-Performance Applications: A Review

Polyurethane foam is a polymeric material having cellular structure. Multifunctional polyurethane foams reinforced with nanofiller have combined enhanced specific properties with density reduction. This article primarily considers important aspects of various foam processing techniques. Numerous nanofillers such as graphite, graphene, graphene oxide, carbon black, carbon nanotube, nanoclay, and inorganic nanoparticle have been reinforced in polyurethane foam. Particular attention is given to various categories of polymer/carbon nanofiller and polymer/inorganic nanofiller composite foams. Applications of polyurethane composite foams have been focused with relevance to aerospace and automotive industry, radar absorbing and electromagnetic interference shielding, oil absorbants, sensors, fire proof, shape memory, and biomedical materials.     

Flexible polyurethane foam. I. FTIR analysis of residual isocyanate

A method for the measurement of residual isocyanate in flexible polyurethane foam by attenuated total reflectance Fourier-transform infrared spectroscopy is described. Residual isocyanate as a function of time was measured in freshly made foams of varying isocyanate index. The effect of relative humidity during storage on the decrease in isocyanate concentration was investigated. As expected, aging under humid conditions was found to decrease the isocyanate concentration faster than under dry conditions. However, even after long periods of time under high humidity, traces of bound isocyanate remained. The fate of the isocyanate is discussed.     

Effect of foam density,oil viscosity,and temperature on oil sorption behavior of polyurethane

This paper examines the effect of foam density, oil viscosity, and temperature on the oil sorption behavior of polyurethane foams. Four polyurethane foams with different densities and two oil types with different viscosities were investigated. The amount of oil uptake was measured gravimetrically. Oil transport through the foams was analyzed by nondestructive X‐ray microtomography. Oil sorption capacity increased significantly with the decrease in foam density, due to the increase in the number of open cells. The oil sorption capacity depended only slightly on sorption temperature and oil viscosity. X‐ray visualization allowed pore filling behavior to be observed directly, and further scope to extend the technique is revealed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 360–367, 2006     

废旧聚氨酯硬质泡沫塑料的降解回收及再利用

采用双组分醇解剂乙二醇（EG）和丙二醇（PG）对废旧聚氨酯（PU）硬质泡沫塑料进行降解,获得了降解产物低聚物多元醇,并将其与木质素为原料制备出再生聚氨酯（r?PU）硬质泡沫塑料复合材料。利用导热系数测定仪、扫描电子显微镜、热重分析仪、傅里叶变换红外光谱仪等对废旧PU的降解效果和r?PU硬质泡沫复合材料的压缩强度、吸水率、导热系数、微观形貌及热稳定性等进行了分析和表征。结果表明,双组分醇解剂EG和PG质量比（m_EG：m_PG）为2：3时,废旧PU的降解效果最佳;当木质素添加量为6 %（质量分数,下同）时制备r?PU硬质泡沫复合材料的泡沫孔壁较厚且比较均匀,骨架几何构型完整,其压缩强度为185.3 kPa、导热系数为0.021 5 W/（m·K）,均能够达到国家标准要求。     

全MDI高回弹泡沫干/湿压缩变形性能的研究

对聚氨酯高回弹泡沫的干、湿压缩变形性能进行了研究,详细考察了配方中水量、聚合物多元醇、交联剂、异氰酸酯指数和官能度变化对聚氨酯高回弹泡沫压缩变形性能的影响,并对产生影响的原因做了初步探讨。     

生物降解聚氨酯切花泥的研制

用魔芋部分代替聚醚多元醇,及甲苯-2,4-二异氰酸酯为主要原料合成了具有较高吸水性、保水性和可生物降解型聚氨酯泡沫。考察了异氰酸指数,硅油用量、反应温度对合成的影响。结果表明最佳的制备条件为魔芋精粉、PPG-3000、甘油为混合聚醚、异氰酸指数1.134;硅油3%、油浴40~50℃、搅拌8h。合成的聚氨酯泡沫有较高吸水性、保水性和生物降解性能,适合用做生物降解切花泥。     

Effect of glycols on the properties of polyester polyols and of room‐temperature‐curable casting polyurethanes

A series of liquid polyester polyols (PEs) from adipic acid (AA), phthalic anhydride (PA) and trihydroxymethylpropane (TMP), and such glycols as ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), butanediol (BD) and hexanediol (HD), were prepared. Polyurethanes (PUs) were obtained from the PEs and polyaryl polymethylene isocyanate (PAPI) at room temperature. The effects of the structures of the glycols on viscosity, glass transition temperature and crystallinity of the PEs, and the mechanical, thermal and boiling‐water‐resistant properties of PUs were studied. The experiments showed that the viscosities and glass transition temperatures of the PEs decreased as the length of the glycol chains increased. The polyester based on HD lost flowability because of crystallization. The tensile strength and hardness of the PUs obtained decreased with increasing the length of the glycol chains, while the resistance to thermal deformation and boiling water increased. Thermogravimetric analysis demonstrated that thermal degradation of the polyurethane based on DEG proceeded in one step and for the others in two steps. The initial degradation temperature of the polyurethane based on EG was the lowest and that of the polyurethane based on BD was the highest. The residue of the former at 450 °C was the greatest, while that of the latter was the lowest. Copyright © 2004 Society of Chemical Industry     

Extruded foams prepared from high amylose starch with sodium stearate to form amylose inclusion complexes*

Extruded starch foams were prepared from high amylose corn starch with and without sodium stearate and poly(vinyl alcohol) (PVOH) to determine how the formation of amylose–sodium stearate inclusion complexes and PVOH addition would affect foam properties. X‐ray diffraction and Differential Scanning Calorimetry (DSC) showed that amylose–sodium stearate inclusion complexes were formed by low temperature extrusion and did not dissociate during foam formation by a second extrusion at higher temperatures. In the absence of PVOH, water absorption, and foam shrinkage at 95% RH were decreased because of the hydrophobicity of the complex. PVOH addition increased both the expansion ratio and the shrinkage of the foam, although shrinkage at 95% RH was still less than that observed with uncomplexed amylose. The structural integrity and some tensile properties of stearate‐containing foams were improved by PVOH addition. These results provide the manufacturer of biodegradable starch foams with an inexpensive method for tailoring foam properties for specific end‐use applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43251.     

Optimizing the lignin based synthesis of flexible polyurethane foams employing reactive liquefying agents

The present work is focused on the optimization of a green process based on the employment of by‐products obtained from wood treatments as raw materials for producing flexible polyurethane foams. More specifically, lignin was employed in flexible polyurethane foams in order to partially replace the usual fossil polyols; therefore glycerol (GLY) and glycerin polyglycidyl ether (EJ 300) were used as the polyol fraction for lignin liquefaction. Polypropylene glycol triol was used as a chain extender in different ratios with liquefaction solvents, and polymeric diphenylmethane diisocyanate as an isocyanate fraction. Liquefaction of lignin was performed by microwave irradiation, thus reducing the processing time and energy required compared to present industrial production processes. All the foams were produced in controlled expansion through the adoption of a ‘one‐shot’ approach, using water as a blowing agent and with an isocyanate index (NCO/OH) of less than 100 to improve the flexibility of the foam. This approach allowed for the substitution of up to 12% of common petro derived polyol with commercial soda lignin. Finally, the foams were characterized, presenting properties that could be modulated as a function of lignin content, GLY/EJ 300 ratio and isocyanate index. The qualities of the foams were compatible with existing materials used for furniture and for the interiors of car seats and couches. © 2015 Society of Chemical Industry     

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     

Hydraulic resistance of rigid polyurethane foams. III. Effect of variation of the concentration of catalysts on foam structure and properties

Water blown rigid polyurethane foams are made using dibutyltin dilaurate and triethanol amine as catalysts. The rate of carbon dioxide generation due to the reaction of isocyanate with water and the rate of polymerization are varied by changing the relative proportion of the catalysts keeping the total catalyst concentration fixed. The foams have densities in the range of 134 to 164 kg/m³. Foams are characterized for hydraulic resistance, “closed cell content,” and compressive modulus. A cell window is the lamella of the foam material that separates two adjacent cells. A strut is generated where three windows of three different cells meet. The cell window area and strut width of the foam cells are measured by optical microscopy. It is found that cell window area and strut width decrease and the respective distribution becomes narrower as the proportion of dibutyltin dilaurate in the total amount of the catalysts is increased. The hydraulic resistance and hence threshold pressure of the foams increases with increase in the proportion of dibutyltin dilaurate. The maximum threshold pressure of 1.81 MPa is observed for the foam made with dibutyltin dilaurate alone. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2838–2843, 2004     

Biodegradable polyurethane foam from liquefied waste paper and its thermal stability,biodegradability, and genotoxicity

Liquefaction of waste paper (WP) was conducted in the presence of polyhydric alcohols to prepare biodegradable polyurethane foam. The liquefied‐WP‐based polyol had suitable characteristics such as apparent molecular weight, hydroxyl value, and viscosity for the preparation of rigid polyurethane foam and was successfully applied to produce polyurethane foam with the appropriate combinations of foaming agents. The obtained foams showed satisfactory densities and mechanical properties as good as those of foams obtained from liquefied wood‐ and starch‐based polyols. The foams had almost the same thermal stability at initial weight loss and seemed to be potentially biodegradable because they were degraded to some extent in leaf mold. There were no mutagens or carcinogens in the water extracts of the foams. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1482–1489, 2002