轻质环氧树脂微孔发泡材料的力学及隔热性能

通过添加不同含量的化学发泡剂,制备了较小密度(0.5 g/cm~3)的环氧树脂基微孔发泡材料,研究了发泡剂含量(0.25%~2%)对环氧复合发泡材料发泡行为的影响,并讨论了材料的力学性能及隔热性能的变化规律。结果表明,随着发泡剂含量的增加,材料的表观密度不断降低,但泡孔尺寸不断增大,泡孔密度则不断降低。力学性能及隔热性能测试表明,随发泡剂含量的增加,材料的压缩屈服强度和压缩弹性模量不断降低,但是材料的隔热性能不断提高。     

Microstructure and properties of epoxy foams prepared by microwave

In this article, epoxy foams comprised of diglycidyl ether of bisphenol‐A (DGEBA) based epoxy resin E₃₁ and E₅₁, polyamide resin, and water were prepared by microwave irradiation method. The structure and properties of epoxy foams were analyzed by FTIR, TGA, SEM, and DMA methods. The density and compressive performance of epoxy foams was also determined. The results indicated that the epoxy foams had excellent compressive performance and the preparation of epoxy foam by microwave irradiation was high efficiency and convenient. The composition has great effect on density, foam structure, dynamical mechanic performance, and thermal degradation behavior of epoxy foams. The epoxy foam with density from 0.08 g cm^?3 to 1.05 g cm^?3 can be obtained by varying ratio of E₅₁ and E₃₁ to control the viscosity of mixtures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚氨酯泡沫材料的性能研究

聚氨酯泡沫具有多孔性、相对密度小、比强度高等特点,根据所用原料的不同和配方的变化可制成阻尼减震性能优异的材料。为了满足铝型材内填充材料的阻尼减震的要求,通过改变原料的组成和配比,制备了一种密度低、阻尼性能优异的聚氨酯泡沫材料。研究了发泡剂、N220和环氧树脂的含量对泡沫材料性能的影响,结果表明调节发泡剂用量可以改变材料的密度和粘接性能,N220和环氧树脂的加入可以提高聚氨酯泡沫的阻尼性能,所制得的聚氨酯泡沫材料可以满足铝型材填充材料的要求。     

Comparative study of physical properties of water‐blown rigid polyurethane foams extended with commercial soy flours

The use of renewable resources (mainly carbohydrates) in rigid polyurethane foam has been known to offer several advantages, such as increased strength, improved flame resistance, and enhanced biodegradability. Less attention has been directed to inexpensive protein‐based materials, such as defatted soy flour. The objectives of this study were to develop water‐blown rigid polyurethane foams, containing defatted soy flour, that have acceptable or improved physical properties which also lower the cost of the foam formulation and to compare the properties of developed foams extended with three kinds of commercial soy flour. Water‐blown low‐density rigid polyurethane foams were prepared with poly(ether polyol)s, polymeric isocyanates, defatted soy flour, water, a catalyst mixture, and a surfactant. Soy flour and the initial water content were varied from 0 to 40% and from 4.5 to 5.5% of the poly(ether polyol) content, respectively. A standard laboratory mixing procedure was followed for making foams using a high‐speed industrial mixer. After mixing, the mixture was poured into boxes and allowed to rise at ambient conditions. Foams were removed from boxes after 1 h and cured at room temperature for 24 h before measurement of the thermal conductivity and for 1 week before other property tests. Foam properties were determined according to ASTM procedures. Measurement of the physical properties (compressive strength, modulus, thermal conductivity, and dimensional stability under thermal and humid aging) of these foams showed that the addition of 10–20% of three kinds of soy flour imparted water‐blown rigid polyurethane foams with similar or improved strength, modulus, insulation, and dimensional stability. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 10–19, 2001     

聚氨酯/环氧树脂互穿网络聚合物硬质泡沫机械性能研究

采用同步法合成了聚氨酯/环氧树脂互穿网络聚合物(PU/EP IPN)硬质泡沫,对机械性能进行了研究。结果表明,与纯聚氨酯硬质泡沫相比,PU/EP IPN硬质泡沫的压缩强度和弯曲强度明显提高,在PU/EP IPN硬质泡沫中,随环氧树脂含量增加,PU/EP IPN硬质泡沫压缩强度和弯曲强度随之增大,当E-39D质量分数增加到24.2%时,PU/EP IPN硬质泡沫压缩强度和弯曲强度出现最大值;PU/EP IPN硬质泡沫机械强度随材料密度的增大而增加;随着环氧树脂中环氧值的增加,PU/EP IPN硬质泡沫的压缩强度、弯曲强度和拉伸强度均呈逐渐升高的趋势。     

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     

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     

Mechanical and thermal properties of phenolic/glass fiber foam modified with phosphorus‐containing polyurethane prepolymer

Phenolic foam exhibits outstanding flame, smoke and toxicity properties, good insulation properties and low production costs. However, the brittleness and pulverization of phenolic foam have severely limited its application in many fields. In this study, a novel phosphorus‐containing polyurethane prepolymer (DOPU) modifier was firstly synthesized, and then the foaming formula and processing of toughening phenolic foam modified with DOPU and glass fiber were explored. The structure and reactive behavior of prepolymer and phenolic resin were investigated using Fourier transform infrared spectroscopy. The effects of DOPU and glass fiber on the apparent density, compressive strength, bending strength and water absorption were investigated. The results suggested that the apparent density, compressive strength and bending strength of modified phenolic foam tended to increase irregularly with increasing content of DOPU. The addition of DOPU led to lower water absorption of glass fiber‐filled foam. Thermal stability and flame retardancy were examined using thermogravimetric analysis and limiting oxygen index (LOI) tests. It was found that foam with 3% DOPU and 0.5% glass fiber added exhibited good thermal stability and high char yields. The LOI value of modified phenolic foams decreased with increasing DOPU content, but it still remained at 41.0% even if the amount of modifier loaded was 10 wt%. © 2012 Society of Chemical Industry     

酚醛泡沫在高温热处理过程中结构与性能的变化

以甲阶酚醛树脂为原料制备了酚醛泡沫,经高温热处理进而得到酚醛树脂基碳泡沫。通过FTIR、TGA、SEM、压缩强度及热导率检测等手段,分析研究了酚醛泡沫在高温热处理后结构与性能的变化情况。结果表明:氮气保护下,酚醛泡沫经高温处理后形成了以碳元素为主的碳泡沫;与酚醛泡沫相比,碳泡沫的表观密度、泡孔孔径较小,泡孔虽仍以闭孔结构为主,但是开孔结构明显增多;酚醛泡沫及碳泡沫的压缩强度和热导率都随着泡沫密度的增加而增大,另外同酚醛泡沫相比,碳泡沫的压缩强度和热导率均相对较高。     

Use of a Mixture of Polyols Based on Metasilicic Acid and Recycled PLA for Synthesis of Rigid Polyurethane Foams Susceptible to Biodegradation

Two polyol raw materials were obtained in the conducted research, one based on metasilicic acid (MSA), the other based on poly(lactic acid) (PLA) waste. The obtained polyols were characterized in terms of their applicability for the production of rigid polyurethane foams (RPUFs). Their basic analytical properties (hydroxyl number, acid number, elemental analysis) and physicochemical properties (density, viscosity) were determined. The assumed chemical structure of the obtained new compounds was confirmed by performing FTIR and ¹H NMR spectroscopic tests. Formulations for the synthesis of RPUFs were developed on the basis of the obtained research results. A mixture of polyols based on MSA and PLA in a weight ratio of 1:1 was used as the polyol component in the polyurethane formulation. The reference foam in these tests was a foam that was synthesized only on the basis of MSA-polyol. The obtained RPUFs were tested for basic functional properties (apparent density, compressive strength, water absorption, thermal conductivity coefficient etc.). Susceptibility to biodegradation in soil environment was also tested. It was found that the use of mixture of polyols based on MSA and PLA positively affected the properties of the obtained foam. The polyurethane foam based on this polyol mixture showed good thermal resistance and significantly reduced flammability in comparison with the foam based MSA-polyol. Moreover, it showed higher compressive strength, lower thermal conductivity and biodegradability in soil. The results of the conducted tests confirmed that the new foam was characterized by very good performance properties. In addition, this research provides information on new waste management opportunities and fits into the doctrine of sustainable resource management offered by the circular economy.     

泡沫炭及其复合材料

本文介绍了泡沫炭的主要性能和泡沫炭复合材料：泡沫炭作为一种新型的炭材料,受到了广泛的关注。它具有密度小、强度高、导电、导热、热稳定、化学稳定等良好的物理和化学性能。泡沫炭复合材料对相对泡沫炭来说力学性能有了一定的提高,其复合材料主要分为五类。本文分别介绍了不同增强相对泡沫炭性能的提升,并就泡沫炭的复合增强方面综述了近年来国内外对泡沫炭及其复合材料的最新研究进展,并指出了泡沫炭的未来研究方向。     

环境友好型阻燃高回弹聚氨酯软泡性能

开发环境友好型聚氨酯是目前聚氨酯（polyurethane,PU）泡沫塑料领域的热点课题。在PU中引入大豆分离蛋白质（soy protein isolate,SPI）,采用阻燃聚醚制备了环境友好型阻燃高回弹聚氨酯软泡。研究了SPI的不同添加方式及用量对聚氨酯软泡物理、力学、阻燃和生物降解性能的影响。结果表明,SPI以添加的方式而不是替代聚醚的方式加入软泡性能更好;少量添加SPI可以提高PU软泡的开孔率、密度、压陷硬度、舒适因子、回弹率和断裂伸长率,对压缩永久变形率、拉伸强度和极限氧指数影响不大。SPI改变了PU的硬段结构,可以有效促进聚氨酯泡沫的生物降解。     

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     

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     

竹炭聚氨酯软质泡沫塑料性能的研究

在聚氨酯泡沬中添加竹炭微粒,运用一步发泡法制备了不同竹炭含量的软质泡沫塑料,测试了该泡沫塑料的密度、力学性能、色差、负离子释放能力及远红外发射率。结果表明,该泡沫塑料的密度、负离子释放能力、回弹率、远红外发射率均随着复合竹炭粉含量的增加而增加;而拉伸强度、断裂伸长率、撕裂强度却随着复合竹炭粉含量的增加而减少;复合竹炭粉含量为8%(质量分数,下同)时的聚氨酯泡沫塑料的拉伸强度、断裂伸长率、撕裂强度分别为纯聚氨酯泡沫塑料的63.87%、57.04%、55.32%;当复合竹炭粉含量≤2%时,制备的竹炭聚氨酯泡沫塑料达到GB/T 10802—2006标准要求。     

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     

蜜氨基聚脲多元醇对聚氨酯泡沫性能的影响

以自制蜜氨基聚脲多元醇为主要原料制备高回弹聚氨酯软泡,研究蜜氨基聚脲多元醇对泡沫的开孔率、密度、回弹率、压陷硬度、水平燃烧速率和氧指数等方面的影响。三聚氰胺聚脲多元醇为其泡沫提供了优良的泡沫压陷硬度和阻燃性。玻璃化温度和热解温度测试值表明蜜氨基聚脲多元醇为其泡沫提供了优异的热稳定性。     

Effect of Evening Primrose (Oenothera biennis) Oil Cake on the Properties of Polyurethane/Polyisocyanurate Bio-Composites

Rigid polyurethane/polyisocyanurate (RPU/PIR) foam formulations were modified by evening primrose (Oenothera biennis) oil cake as a bio-filler in the amount of 5 to 50 wt.%. The obtained foams were tested in terms of processing parameters, cellular structure (SEM analysis), physico-mechanical properties (apparent density, compressive strength, brittleness, accelerated aging tests), thermal insulation properties (thermal conductivity coefficient, closed cells content, absorbability and water absorption), flammability, smoke emission, and thermal properties. The obtained results showed that the amount of bio-filler had a significant influence on the morphology of the modified foams. Thorough mixing of the polyurethane premix allowed better homogenization of the bio-filler in the polyurethane matrix, resulting in a regular cellular structure. This resulted in an improvement in the physico-mechanical and thermal insulation properties as well as a reduction in the flammability of the obtained materials. This research provided important information on the management of the waste product from the edible oil industry and the production process of fire-safe RPU/PIR foams with improved performance properties. Due to these beneficial effects, it was found that the use of evening primrose oil cake as a bio-filler for RPU/PIR foams opens a new way of waste management to obtain new “green” materials.     

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     

Rigid polyurethane foams based on activated soybean meal

Soybean meal (SM), an abundant biomass resource, was used as the surrogate to partially replace polyols in rigid polyurethane foam synthesis. Compared with polyurethanes based on other soybean‐based resources, such as soybean protein isolate (SPI), polyurethane foams based on activated SM showed better thermal and mechanical properties. The amount of SM in the final polyurethane foams can be as high as 30 wt % (base on the total weight of foam), which dramatically decreases the cost of the foams. The results also showed that SM played a vital role in improving the foam properties, which could be attributed to the participation of the functional groups in SM in the polyurethane foam synthesis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012