环氧树脂加成多元醇增加聚酯软质泡沫塑料

用双酚A型环氧树脂与乙酸反应,合成了具有刚性骨架的环氧树脂加成多元醇（EAP）,并用FTIR与1H-NMR对其进行了表征。研究结果表明,工业聚醚多元醇中添加EAP后制备的全水发泡软质聚氨酯（PU）泡沫塑料的压入硬度显著提高,但回弹性不变。进一步研究了不同水用量对所制备PU软质泡沫塑料力学性能的影响。并用FTIR和光学显微镜考察了PU软质泡沫塑料中脲基的氢键行为和泡孔结构,结果表明,在PU软质泡沫塑料中引入EAP刚性链对PU泡沫塑料的结构及性能有很大影响。     

粗聚醚多元醇精制工艺的研究

以ZS 2 80 1碱性粗聚醚多元醇为原料 ,采用吸附法 ,研究了聚醚多元醇中杂质钾、钠离子的脱除精制工艺。结果表明 ,成品聚醚多元醇中的钾、钠离子总量可控制在 10× 10 - 6 以下 ,可以满足软质PU泡沫塑料的应用要求。选用的吸附剂具有价廉、夹带成品聚醚多元醇少等优点。     

聚氨酯改性环氧树脂的合成及其复合材料性能研究

以2,4-甲苯二异氰酸酯、聚乙二醇为主要原料合成端异氰酸酯基聚氨酯预聚体,与环氧树脂混合,用D-230进行固化,得到PU/EP复合材料。研究了聚氨酯不同含量对环氧树脂力学性能的影响,并用FTIR进行了表征,通过DMA研究了PU/EP复合材料的阻尼性能。结果表明,加入聚氨酯明显改善了EP的性能。     

聚氨酯改性环氧树脂胶粘剂的性能研究

以聚酯多元醇和甲苯-2,4-二异氰酸酯(TDI)合成了—NCO封端的聚氨酯预聚物,然后与环氧树脂反应,得到聚氨酯改性环氧树脂(PU/EP),并用PU/EP为原料制备了改性环氧树脂胶粘剂。采用傅里叶变换红外光谱仪(FT-IR)对聚氨酯改性环氧树脂进行了表征,考察了PU含量对改性环氧胶粘剂的剪切强度、剥离强度、硬度及耐热性的影响,分析了PU含量对改性环氧胶粘剂外观和微观形貌的影响。研究结果表明:当w(PU)=20%(相对于总质量而言)时,改性环氧胶粘剂的粘接性能达到最佳:剪切强度为29.9 MPa,比改性前提高27%;剥离强度为4.56 N/mm,比改性前提高251%;但是硬度和玻璃化转变温度(Tg)降低,硬度为73.4,Tg为59.69℃。     

水性萜烯基EP/PU复合聚合物的制备及其交联反应与特性(摘要)

以来源于松节油的萜烯基环氧树脂(TME)为基体树脂,对其进行亲水化、羟基化改性合成水性萜烯基环氧树脂多元醇,再与多异氰酸酯交联,制备双组分水性萜烯基环氧树脂(EP)/聚氨酯(PU)复合聚合物.主要研究了水性萜烯基环氧树脂多元醇的合成工艺、结构表征,多元醇水分散体的稳定性、流变性、粒子形态、粒径分布等;水性萜烯基EP/PU复合体系的交联反应动力学及其反应机理与多元醇化学结构的内在关系;复合体系的流变特性、成膜过程及其复合产物的性能与结构的内在关系.为实现我国天然萜烯可再生资源的高值化高效综合利用及其在环境友好型高分子材料中的应用提供良好的理论基础.     

反应型火焰复合剂对聚醚型聚氨酯软质泡沫塑料火焰复合性能的影响

在泡沫生产配方中分别添加火焰复合剂、阻燃剂和聚酯多元醇,研究了这些添加剂对聚醚型聚氨酯软质泡沫塑料和织物火焰复合性能的影响,并对火焰复合的机理进行了探讨。结果表明,相对于其他两种添加剂而言,反应型的火焰复合剂可以大幅度提高聚醚型聚氨酯软质泡沫塑料和织物的剥离强度,且对泡沫塑料的物理力学性能没有负面的影响。添加剂类型、火焰强度、织物种类以及异氰酸酯指数都对材料剥离强度有很大影响。     

聚氨酯对环氧树脂增韧性能研究

利用甲苯二异氰酸酯(TDI)和聚丙二醇(PPG)合成不同结构的端—NCO聚氨酯(PU)预聚体,然后由聚氨酯预聚体与环氧树脂进行接枝反应,制备聚氨酯改性环氧树脂。研究了聚氨酯预聚体结构和用量对改性环氧树脂力学性能的影响规律。结果表明,当聚醚多元醇选用PPG1000,且TDI∶PPG=2∶1时,制得的聚氨酯预聚体对环氧树脂的增韧效果最好,当ω(PU预聚体)=10%时,改性环氧树脂的应变和拉伸强度分别达到84. 7%和27. 1 MPa,是改性前的30. 47倍和3. 04倍。通过扫描电镜对聚氨酯的增韧机理进行了研究,发现改性前环氧树脂为脆性断裂,聚氨酯改性后的环氧树脂断裂时银纹明显增多,为韧性断裂。     

聚氨酯对环氧树脂增韧性能研究

利用甲苯二异氰酸酯(TDI)和聚丙二醇(PPG)合成不同结构的端—NCO聚氨酯(PU)预聚体,然后由聚氨酯预聚体与环氧树脂进行接枝反应,制备聚氨酯改性环氧树脂。研究了聚氨酯预聚体结构和用量对改性环氧树脂力学性能的影响规律。结果表明,当聚醚多元醇选用PPG1000,且TDI∶PPG=2∶1时,制得的聚氨酯预聚体对环氧树脂的增韧效果最好,当ω(PU预聚体)=10%时,改性环氧树脂的应变和拉伸强度分别达到84. 7%和27. 1 MPa,是改性前的30. 47倍和3. 04倍。通过扫描电镜对聚氨酯的增韧机理进行了研究,发现改性前环氧树脂为脆性断裂,聚氨酯改性后的环氧树脂断裂时银纹明显增多,为韧性断裂。     

酚醛树脂改性聚氨酯硬质泡沫塑料的研究

在多元醇中掺入甲阶酚醛树脂，与异氰酸酯反应，可以获得具有PF阻燃性和PU绝热性能的PF／PU共聚硬质泡沫塑料。介绍了甲阶酚醛树脂制备方法，并对其合成工艺、反应条件控制等进行了较详尽的探讨。     

废聚氨酯软质泡沫塑料的粘接再生

对聚醚多元醇为基的端异氰酸酯基聚氨酯粘合剂粘接废聚氨酯软质泡沫塑料的粘接工艺进行了研究。用该粘合剂喷涂废聚氨酯软质泡沫塑料碎料,在模具中加压,固化后,得到的泡沫体具有良好物理机械性能。     

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。     

Synthesis of a green reactive flame-retardant polyether polyol and its application

The low-flame retardancy properties of pure rigid polyurethane (PU) foams hindered its practical application in many cases for the safety and environmental concern. Although rigid PU foams with flame retardants can achieve standard of fire resistance, addition of flame retardants in PU can worsen its mechanical properties, enlarge production cost, and induce safety problems. Therefore, green reactive flame-retardant polyether polyols (GPP) have been considered as one of the best solutions. In this work, the GPP by the ring-opening polymerization of the self-made environmentally friendly melamine resin (EFMR) with propylene oxide are synthesized with their hydroxyl number of 390 ~ 420 mg KOH/g, and the structure of GPP product was identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The flame-retardant rigid polyurethane foams (RPUFs) were successfully prepared with GPP as the polyol, the results showed that the addition of GPP can greatly improve the thermal stability and flame retardancy of the RPUFs prepared. The RPUF were prepared by fully GPP with 30.4% of limiting oxygen index and 350 kpa of compressive strength. These properties are qualified for commercial utilization. Therefore, this GPP provides great prospect in the development of specified flame-retardant PU materials.     

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     

Flexible polyurethane foams synthesized employing recovered polyols from glycolysis: Physical and structural properties

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.     

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     

Influence of structure of hydroxyl-terminated maleopimaric acid ester on thermal stability of rigid polyurethane foams

A series of hydroxyl-terminated maleopimaric acid esters (HTMAEs) and rigid polyurethane (PU) foams based on these HTMAEs were synthesized using chemically modified natural gum rosin and its derivative maleopimaric acid as raw materials. Thermal stability of these polyols and their corresponding rigid PU foams was studied by a thermogravimetric method and a dimensional stability measurement. It was shown that the thermal stability of the final foams was strongly dependent on the structure of their corresponding polyols. The thermogravimetric analysis curves of these rosin-based rigid PU foams displayed two distinct regions of weight loss. It has been shown that at the initial stage of weight loss the process was dominated by polyol component degradation; the second stage was governed by isocyanate component degradation. © 1995 John Wiley & Sons, Inc.     

Preparation and characterization of microencapsulated ammonium polyphosphate and its synergistic flame‐retarded polyurethane rigid foams with expandable graphite

A facile and effective method for the preparation of microencapsulated ammonium polyphosphate (MAPP) by in situ surface polymerization was introduced. The ‘polyurethane‐like’ shell structure on the surface of MAPP was characterized by using Fourier transform infrared spectroscopy. The hydrophobicity and thermal behavior of MAPP were studied by using water contact angle tests and thermogravimetric analysis. The foam density and mechanical properties of polyurethane (PU) rigid foams were investigated. The flame retardancy of PU rigid foams formulated with MAPP was evaluated by using limiting oxygen index and cone calorimetry. The results show that MAPP can greatly increase the flame retardancy of PU materials. Also, there is a synergistic effect between MAPP and expandable graphite in flame retarding PU rigid foams. Moreover, the water resistance property of PU/MAPP composites is better than that of PU/ammonium polyphosphate. The morphology and chemical structure of PU/MAPP rigid foams after burning were systematically investigated. © 2013 Society of Chemical Industry     

Manufacture and use of pulverized flexible polyester polyurethane foam particles

Crucial process modifications were shown necessary to improve the economics of cryogenic grinding of flexible polyurethane (PU) foam. It is concluded that foam densification prior to cryogenic processing was essential to reduce insulation effects. In comparative studies of foam and densified foam, increasing the density to ～800 kg/m³ resulted in dramatically reduced cryogen use and vastly improved output. Results indicated that cryogenic pulverization presents a significantly more economic solution than previously recognized. Particles produced by this method were added to foam formulations and effects of particle size and structure on compression properties and cell structure of resultant foams were studied. Particle sizes <100 μm gave similar compression properties and cell size to virgin foam at up to 10 parts by weight on 100 parts of polyol, but cell structure and compressive properties showed increasing divergence as particle size and addition concentration increased. Studies of alternative uses showed that the PU particles showed promise as fillers in rigid PU foam formulations and suggested an extending or reinforcing action in natural rubber vulcanizates.     

Morphology,mechanical properties,and thermal stability of polyurethane–epoxide resin interpenetrating polymer network rigid foams

A series of rigid interpenetrating network foams (IPNFs) based on a rosin‐based polyurethane (PU) and a crosslinked epoxide resin (ER) were prepared by a simultaneous polymerization technique. The morphology, mechanical properties, thermal stability, and changes in the chemical structure during the thermal degradation process of the rigid IPNFs were investigated by scanning electron microscopy (SEM), compressive testing, thermogravimetric analysis (TGA), and Fourier‐transform infrared spectroscopy (FTIR). The SEM micrographs showed that the cell structure of the rigid IPNFs became less homogeneous with increasing ER content. The brittleness of the cell walls increased as the ER content and the cure time of the rigid IPNFs increased. The compressive strength of the rigid PU/ER IPNFs increased to a maximum value and then decreased with further increase in the ER content. Similar behavior was observed for the elastic modulus. This behavior was related to the nonhomogeneous cells and more brittle cell walls for the rigid IPNFs with high ER content. The TGA data showed that the thermal stability of the rigid PU foam increased with the addition of increasing levels of ER, due to the better thermal stability of the ER compared to that of the PU. With the exception of the ER alone, a two‐stage weight‐loss process was observed for all these rigid IPNFs and for the PU foam alone. The FTIR analysis suggested that the first stage of weight loss was due to the degradation of the polyol–derived blocks of the PU, and the second weight loss stage was governed by both the degradation of the ER component and that of the isocyanate‐derived blocks of the PU. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 406–416, 2000     

Role of additives in fabrication of soy-based rigid polyurethane foam for structural and thermal insulation applications

Environmental concerns continue to pose the challenge to replace petroleum-based products with renewable ones completely or at least partially while maintaining comparable properties. Herein, rigid polyurethane (PU) foams were prepared using soy-based polyol for structural and thermal insulation applications. Cell size, density, thermal resistivity, and compression force deflection (CFD) values were evaluated and compared with that of petroleum-based PU foam Baydur 683. The roles of different additives, that is, catalyst, blowing agent, surfactants, and different functionalities of polyol on the properties of fabricated foam were also investigated. For this study, dibutyltin dilaurate was employed as catalyst and water as environment friendly blowing agent. Their competitive effect on density and cell size of the PU foams were evaluated. Five different silicone-based surfactants were employed to study the effect of surface tension on cell size of foam. It was also found that 5 g of surfactant per 100 g of polyol produced a foam with minimum surface tension and highest thermal resistivity (R value: 26.11 m²·K/W). However, CFD values were compromised for higher surfactant loading. Additionally, blending of 5 g of higher functionality soy-based polyol improved the CFD values to 328.19 kPa, which was comparable to that of petroleum-based foam Baydur 683.