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1.
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 相似文献
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The effect of different palm oil‐based bio‐polyols on foaming process and selected properties of porous polyurethanes
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Norma E Marcovich Maria Kurańska Aleksander Prociak Elżbieta Malewska Sonia Bujok 《Polymer International》2017,66(11):1522-1529
Rigid polyurethane foams were successfully prepared by blending up to 70 wt% of two different palm oil‐based bio‐polyols with a petrochemical polyether polyol. The bio‐polyols were synthesized by epoxidation–oxirane ring‐opening process using water (PP102) and diethylene glycol (PP147), respectively. Due to the high viscosity of both bio‐polyols the reactive mixture was heated to start the foaming reaction at about 50 °C. Under these conditions, the gelling reactions speed up as the amount of PP147 increases but slow down to a great extent when PP102 is used. The thermal conductivity of modified foams is higher and the closed cell content lower compared to reference ones, even when the bio‐foams present a lower apparent density. However, all foams exhibit reduced water absorption, excellent dimensional stability and better thermal stability at temperatures up to 400 °C than the control foam. Conversely, their mechanical and dynamic mechanical properties become poorer as the PP147 concentration increases and even more so if PP102 is used instead. PP147 foams containing up to 50% bio‐polyol could be used as a green replacement of petroleum‐based ones in applications where excellent behaviour in compression (the most affected properties) is not fundamental, with the additional advantages of reduced density and increased content of bio‐derived components. © 2017 Society of Chemical Industry 相似文献
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Flexible polyurethane foams synthesized employing recovered polyols from glycolysis: Physical and structural properties
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Polyurethane (PU) is one of the most important polymers with a global production of 17.565 million tons, which makes its recycling an urgent task. Besides, the main goal of PU recycling is to recover constituent polyol as a valuable raw material that allows to obtain new PU with suitable properties. Split‐phase glycolysis can be considered the most interesting PU recycling process since provides high‐quality recovered products in terms of polyol purity. The aim of this work was to evaluate several recovered polyols as replacement of the raw flexible polyether polyol in the synthesis of new flexible PU foams. These recovered polyols come from the split‐phase glycolysis of different types of PU foams and employing as cleavage agents diethylene glycol or crude glycerol (biodiesel byproduct). The influence of the foam waste type and of the cleavage agent on the foams properties was analyzed. The recovered polyols were evaluated by performing several foaming tests according to the method of free expansion foaming of conventional flexible foam. Synthesized flexible foams containing different proportions of recovered polyols were characterized by means of scanning electron microscopy, density and tensile properties; obtaining similar and sometimes even better values compared to the foams manufactured from commercial polyols. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45087. 相似文献
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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. 相似文献
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In this study, the viscoelastic and morphological properties of molded foams were investigated to determine the influence of the presence or absence of reinforcing particulate copolymer polyols (CPP). The molded foams were based on toluene diisocyanate (TDI) and glycerol‐initiated ethylene‐oxide endcapped polypropylene oxide and, in most samples, some amount of copolymer polyol. Two series of foams were studied. In Series 1, as CPP is added to the formulation, the amount of TDI fed is kept constant. This results in a constant amount of hard‐segment content as the filler in the system displaces, by weight, the polyether polyol in the foam, and it increases the hard segment to soft segment ratio (HS/SS). In Series 2, the amount of hard‐segment material is proportionally decreased as CPP is added, resulting in a constant HS/SS ratio. Structural investigations of the foams displayed rather similar textures. The cellular structures of a CPP‐containing foam was very similar to a foam lacking the copolymer polyols. Transmission electron microscopy revealed that the CPP particles were well dispersed and that they possessed significant rigidity even at high temperature and under high compression. Although all of the foams were microphase‐separated, they varied slightly in that the copolymer polyol containing foams exhibited higher weight fractions of extractables in both Series 1 and Series 2. This suggests that not all of the CPP material is covalently bonded into the polyol matrix. It was found that temperatures above ambient as well as humidity plasticized the viscoelastic behavior of all the molded foams evaluated. It was also found that the copolymer polyol particles, as added to the molded foams of Series 1, increased load‐bearing capabilities but had a negative effect on the stress relaxation, creep, and compression set properties. In particular, the viscoelastic properties of the CPP‐containing foam were distinctly more time‐dependent than those of the foam lacking these particles. However, the Series 2 foams show that most of these effects are a result of the increased HS/SS ratio and not a result of the CPP particulate. It was shown that adding CPP while maintaining a constant HS/SS ratio improves percent load loss and load bearing under high‐humidity conditions, two important properties in flexible polyurethane foams. Finally, it was shown that at high temperatures (ca. 100°C), an additional relaxation mechanism occurs which cannot be attributed to changes in the HS/SS ratio, but must be a result of the CPP components themselves. This additional mechanism results in higher rates of load relaxation and creep in foams containing CPP at high temperatures for foams of both series. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 766–786, 2000 相似文献
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One‐step manufacturing process (in‐situ foaming) provide great potential for the production of foam core panels. Polyurethane (PU) foam showed good applicability for use for in‐situ foaming. Here, the effect of ingredient ratios of rigid PU foam on foam performance and panel properties is investigated. It was observed that the isocyanate (ISO) content and polyols (PO) type and content significantly change the foam and panel properties. Foam cell density, as the most important factor influencing the foam characteristics, was higher in foams with higher ISO and polyether content. Bending strength, internal bond and screw withdrawal resistance of the foam core panels were significantly enhanced when the ISO and polyether content was increased in the foam formulation. Varying the ISO content had no influence on panel properties with higher content of polyester (60%) in the PO blend. Varying the foam ingredient ratios did not change the thickness swelling, while the water absorption was dependent on the foam components ratios. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44722. 相似文献
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The focus of this work was to synthesize bio‐based polyurethane (PU) foams from soybean oil (SO). Different polyols from SO were produced as follows: soybean oil monoglyceride (SOMG), hydroxylated soybean oil (HSO), and soybean oil methanol polyol (SOMP). The SOMG was a mixture of 90.1% of monoglyceride, 1.3% of diglyceride, and 8.6% of glycerol. The effect of various variables (polyol reactivity, water content curing temperature, type of catalyst, isocyanate, and surfactant) on the foam structure and properties were analyzed. SOMG had the highest reactivity because it was the only polyol‐containing primary hydroxyl (? OH) groups in addition to a secondary ? OH group. PU foams made with SOMG and synthetic polyol contained small uniform cells, whereas the other SO polyols produced foams with a mixture of larger and less uniform cells. The type of isocyanate also had an influence on the morphology, especially on the type of cells produced. The foam structure was found to be affected by the water and catalyst content, which controlled the foam density and the cure rate of the PU polymer. We observed that the glass transition (Tg) increased with the OH value and the type of diisocyanate. Also, we found that the degree of solvent swelling (DS) decreased as Tg increased with crosslink density. These results are consistent with the Twinkling Fractal Theory of Tg. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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高阻尼聚氨酯结构泡沫材料的研究 总被引:7,自引:0,他引:7
探讨了高阻尼PU结构泡沫的配方、工艺和性能。结果表明:以六官能团的聚醚多元醇和有机多异氰酸酯(PAPI)制得的PU结构泡沫力学性能最优;反应对胺类催化剂和有机锡类催化剂的比例及用量非常敏感;硅酮类泡沫稳定剂对泡沫体的性能起重要作用;发泡剂F11可用符合环保要求的戊烷完全替代;一种粉状填料和短切玻纤的加入可显著提高PU结构泡沫的损耗因子和冲击强度值。 相似文献
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用酚醛-三聚氰胺聚合物改性的聚醚多元醇(PFMP-Polyol)制备硬质聚氨酯泡沫,考察了PFMP-Polyol的用量对泡沫的发泡性能、物理机械性能的影响。结果表明,在HCFC-141b发泡体系中,PFMP-Polyol的加入可提高发泡反应速度,使泡沫泡孔细腻、均匀,泡沫的压缩强度、尺寸稳定性均有明显的提高;用于环戊烷发泡体系中,当PFMP-Polyol的质量分数占聚醚多元醇的30%、模压泡密度在34.2 kg/m~3,压缩强度(水平方向)为254.2 kP,导热系数可降低至20.8 mW/(m·K)。 相似文献
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无CFC硬泡用低粘度聚醚多元醇 总被引:4,自引:0,他引:4
介绍了一种具有自乳化性、高羟值低粘度聚醚多元醇。以该聚醚多元醇为基础,制备了无CFC或CFC减半PU硬泡,包括HCFC-141b减关体系、正(异)戊烷发泡体系、全水发泡及CFC-11减半体系。实验结果表明,该聚醚与HCFC-141b、戊烷及水等相溶性好,组合料贮存稳定,硬泡物性优良,说明该聚醚可广泛应用于各种无CFC PU硬泡体系。 相似文献
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以自产聚醚多元醇为主要原料 ,试制成普通块状软泡。讨论了催化剂用量、填料用量、密度等对泡沫性能的影响 ,并与普通软泡聚醚所制泡沫的性能进行比较 相似文献
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以环氧丙烷聚醚多元醇、苯酐聚酯多元醇、多苯基甲烷多异氰酸酯PM-200、发泡剂一氟二氯乙烷(HCFC-141b)、泡沫稳定剂硅油AK-8801等为主要原料,采用一步法合成了聚氨酯硬泡,考察了不同种类多元醇及其配比、发泡剂、泡沫稳定剂种类及用量等对聚氨酯硬泡抗压性能的影响。结果表明:高羟值、高官能度的环氧丙烷聚醚多元醇可提高泡沫的压缩强度,且当环氧丙烷聚醚多元醇4110为100份,并加入20份左右苯酐聚酯多元醇580及10份左右聚醚403,泡沫稳定剂用量1~2份,发泡剂水用量0.5~1份,HCFC-141b用量30~35份,催化剂用量0.5~1.5份时,所得聚氨酯硬泡性能较好。 相似文献
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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 相似文献
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以一种多元胺类副产物为起始剂,制备了一种叔胺基聚多元醇。它具有粘度低,反应活性高,与其它多元醇相窝性好,价格低等优点,它用于硬质聚氨酯泡沫塑料制备时,使泡沫的强度,泡孔结构等得到明显改善,在聚氨醌泡生产领域具有良好的发展前途。 相似文献
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将高活性自催化聚醚多元醇应用于高回弹泡沫中,通过发泡实验确定了其自催化活性及与胺类催化剂配合使用时的最佳配比;该聚醚多元醇用于TM体系也可起到催化作用。同时,与用普通聚醚多元醇制得的泡沫相比,用该聚醚多元醇制得的泡沫VOC值明显降低。 相似文献
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Polyurethanes (PUs) represent one of the most important groups of plastics, and so the increasing quantity of wastes makes their recycling an urgent task. The general purpose of PU chemical recycling is to recover constituent polyol, a valuable raw material. Among the suitable processes, glycolysis in two phases allows better quality products. The objective of this work is the evaluation of the option to apply the recovered polyols to obtain PU with identical characteristics to the starting raw material, and so several foaming tests were carried out according to the evaluation method employed in free expansion foaming of conventional flexible slabstock foams. To achieve this objective, a formulation recipe for flexible foams was selected, in which the raw polyol was totally or partially replaced for recovered polyol. The foaming formulations were modified because of the different amount of active hydrogens in the recovered polyols and the virgin polyol. Amounts up to 50% could be applied without relevant changes in rising profiles and the physical properties of the foams. The foams were characterized, and according to its appropriate characteristics they can be employed in the same applications where a commercial one made with raw polyol is used. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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Christian Lenges Natnael Behabtu Jorge Mok Ibrahim Sendijarevic Aisa Sendijarevic 《应用聚合物科学杂志》2021,138(10):49979
Enzymatic polymerization is emerging as scalable method to convert sucrose to engineered polysaccharides. Polymer architecture and material properties can be controlled selectively to produce novel differentiated biomaterials. One first example for such an engineered polysaccharide is alpha-1,3-polyglucose (alpha-1,3-glucan) synthesized using glucosyltransferase (GTF) enzymes. Stable dispersions of alpha-1,3-glucan in polyether polyols were prepared with narrow particle size distributions, which are reactive with isocyanate allowing for covalent bonding to the hard segment of the polyurethane polymer matrix. This study further explored the use of alpha-1,3-glucan (PS) in the preparation of viscoelastics (VE) polyurethane foams. The introduction of alpha-1,3-glucan into the polyurethane polymer matrix was found to increase the load-bearing properties of VE foams without impacting the density. Other key performance properties of VE foams were effectively unchanged, including resilience, tensile, and tear strength. Cell size and morphology were also unaffected. The glass transition of these VE foams was not impacted; however, the overall thermal dimensional stability was improved as considerable reduction in compression set was observed. The results of this study indicated that alpha-1,3-glucan disperses in polyether polyols to improve performance characteristics of the VE foams, as well as other flexible polyurethane foams properties. 相似文献