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纳米二氧化硅改性硬质聚氨酯泡沫塑料的研究 总被引:2,自引:0,他引:2
采用浇注成型法合成密度为250 mg/cm3的纳米SiO2改性硬质聚氨酯泡沫塑料(PUR-R),研究了纳米SiO2含量及偶联剂处理对纳米SiO2改性PUR-R的各种力学性能的影响。结果表明:直接使用纳米SiO2,可使PUR-R的某些力学性能得到提高,而偶联剂处理可进一步改善纳米SiO2对PUR-R的增强作用,用偶联剂改性过的纳米SiO2增强PUR-R与纯PUR-R相比,除断裂伸长率降低外,其他力学性能如拉伸强度、压缩强度、弯曲强度、冲击强度及弯曲模量等均有所提高。 相似文献
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A composite foam, polyurethane–melamine formaldehyde (PU/MF) foam, was prepared through foaming PU resins in the three‐dimensional netlike skeleton of MF foam. The chemical structure, morphology, cell size and distribution, flame retardancy, thermal properties and mechanical properties of such composite foam were systematically investigated. It was found that the PU/MF foam possessed better fire retardancy than pristine PU foam and achieved self‐extinguishment. Moreover, no melt dripping occurred due to the contribution of the carbonized MF skeleton network. In order to further improve the flame retardancy of the composite foam, a small amount of a phosphorus flame retardant (ammonium polyphosphate) and a char‐forming agent (pentaerythritol) were incorporated into the foam, together with the nitrogen‐rich MF, thus constituting an intumescent flame‐retardant (IFR) system. Owing to the IFR system, the flame‐retardant PU/MF foam can generate a large bulk of expanded char acting as an efficient shielding layer to hold back the diffusion of heat and oxygen. As a result, the flame‐retardant PU/MF foam achieved a higher limiting oxygen index of 31.2% and exhibited immediate self‐extinguishment. It exhibited significantly reduced peak heat release rate and total heat release, as well as higher char residual ratio compared to PU foam. Furthermore, the composite foam also showed obviously improved mechanical performance in comparison with PU foam. Overall, the present investigation provided a new approach for fabricating a polymer composite foam with satisfactory flame retardancy and good comprehensive properties. © 2018 Society of Chemical Industry 相似文献
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M. Thirumal Dipak Khastgir Nikhil K. Singha B. S. Manjunath Y. P. Naik 《应用聚合物科学杂志》2008,108(3):1810-1817
Density is an important parameter that influences the properties and performances of rigid polyurethane foam (PUF). Rigid PUF with different densities were prepared by varying the amount of distilled water as blowing agent. This investigation reports the mechanical, morphological, water absorption, thermal conductivity, and thermal behavior of rigid PUF varying with the density, which controls the foam architecture. The density of the PUF decreased from 116 to 42 kg/m3 with an increase in the amount of water from 0.1 to 3.0 parts per hundred polyol by weight (phr), respectively. It was found that the mechanical properties of the PUFs changed with the foam density. The results of water absorption of the PUFs showed that water absorption increased with decrease in density, due to increase in the cell size and decrease in the cell‐wall thickness. The thermal conductivity measurements showed that the thermal conductivity decreased with increase in density. It was due to the decrease in cell size. The thermal analysis of the PUFs shows that the glass transition temperature increases with the decrease in foam density, but the thermal stability decreases with the decrease in foam density. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 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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Jiazi Wu Xin Zhang Zhaolu Qin Wenchao Zhang Rongjie Yang 《Polymer Engineering and Science》2023,63(3):1041-1049
The flame-retardant rigid polyurethane foam (RPUF) composites are fabricated by ammonium polyphosphate (APP) with pentaerythritol phosphate (PEPA), phenoxycycloposphazene (PCP), and aluminum diethylphosphinate (ADP), respectively, which are labeled as RPUF-1, RPUF-2, and RPUF-3. The influence of flame retardants on the apparent density and compressive strength of RPUF is studied. The results reveal that flame retardants not only improve the apparent density, but also improve the compressive strength of RPUF composites. The limiting oxygen index (LOI) results reveal that these inorganic/organic phosphorus-based flame retardants improve the LOI significantly, especially for RPUF-2 and RPUF-3 systems. The cone calorimeter test results suggest that the peak of heat release of RPUF-1, RPUF-2, and RPUF-3 systems decrease by 38%, 41%, and 52% likened to that of pure RPUF. And APP and ADP system performs best in declining the heat release. And APP and PEPA systems perform best in decreasing the smoke release. The flame retardancy mechanism of RPUF composites is analyzed in details. 相似文献
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The design of environment-friendly fireproof rigid polyurethane foams (RPUFs) that completely prevent ignition or the spread of fires is important for energy conservation and emission reductions. In this paper, an intumescent flame-retardant coating was prepared and coated onto the surface of a RPUF to improve its flame retardancy. Vertical combustion experiments (UL-94) showed that, compared with the pure RPUF, a RPUF coated with the expansion coating successfully self-extinguished without a droplet formed after ignitor removal. Thermogravimetric analyses showed that the expanded coating effectively increased the rate of carbon residue formation. Cone calorimetry showed that when the pigment-to-binder ratio was 3.5:1, with 5% modified montmorillonite, 6% aluminum hydroxide, and 4% titanium dioxide, the intumescent coating effectively reduced the heat release rate and total heat release of the RPUF. Remarkably, the smoke release rate and total exhaust gas volume showed that the expanded coating provided obviously enhanced smoke suppression. Therefore, the flame retardancy and toxic smoke suppression provided by the RPUF thermal insulation material is essential and very useful for healthy development of human society and the environment. 相似文献
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Jiaji Cheng Shaoshuai Niu Dan Ma Yue Zhou Feng Zhang Wenjuan Qu Dong Wang Shaoxiang Li Xinlong Zhang Xianqun Chen 《应用聚合物科学杂志》2020,137(48):49591
In this article, a flame retardant microcapsule ammonium polyphosphate microencapsulated by polyurea (POAPP) was successfully synthesized by interfacial polymerization method using ammonium polyphosphate (APP) as core and polyurea as shell. The microencapsulation is observed by scanning electron microscopy and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and hydroscopicity test, which prove the success in synthesizing microencapsulation. When the POAPP is added into rigid polyurethane foam (RPUF), the flame retardant and mechanical properties are investigated using cone calorimeter, limited oxygen index test, and compressive strength test. The PHRR of RPUF-POAPP20 decreased from 336.52 kW/m2 (Ref. RPUF) to 203.84 kW/m2 and the THR of RPUF-POAPP20 was only 7.6 MJ/m2, which is 33.9% lower than that of Ref. RPUF. Furthermore, the limiting oxygen index of RPUF-POAPP20 reaches 24.8%, which increased by 36.3% compared to Ref. RPUF. Whereas the maximum compressive strength of RPUF-POAPP5 was 7.46 MPa, which is higher than that of RPUF-APP5. 相似文献
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The objective of this study is to investigate an appropriate process to fabricate the wood‐polyurethane hybrid composites [wood‐polyurethane foam (PUF)]. Rigid PUFs that contain up to 20% wood flours were successfully fabricated from polymeric 4,4‐diphenylmethane diisocyanate, polyols, silicone surfactant, dibutin dilaurate/dimethylethanolamine catalysts, and distilled water (chemical blowing agent). The effects of hydroxyl value of polyols, wood flour particle size, wood flour content, isocyanate index, and water amount on the compressive property of foam were investigated. The morphology of the cell was observed with a scanning electron microscope. Wood‐PUF with different densities were prepared at different water contents in the wood flours. The relationship between the compressive property and density was established following the Power law. The incorporation of wood flour improved the compressive property of PUF, whereas its tensile and flexural properties were reduced. The thermal stability of the PUF was improved with the addition of wood flour. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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高密度聚氨酯硬泡塑料/玻纤粉复合材料的研究 总被引:2,自引:1,他引:1
以聚醚多元醇、PAPI、催化剂、发泡剂和玻璃纤维等为原料,制备高密度聚氨酯硬泡及它与磨碎玻纤粉的复合材料。研究了不同密度硬泡的强度及磨碎玻纤粉粒径、预处理及其含量对复合材料强度的影响,不同复合材料的热稳定性。结果表明,随着密度的增加,硬泡的各种强度值总体上均呈逐渐增加趋势,其中500kg/m^3的聚氨酯的拉伸强度比200kg/m^3的提高了104.74%,冲击强度提高了194.84%;400目粒径的玻纤粉可使复合材料具有更高的拉伸强度、弯曲强度及压缩强度;玻纤的加入将降低材料的强度值,但偶联剂预处理可使它们有所改善;加入磨碎玻纤粉后,材料的热稳定性增加,且采用偶联剂KH550对玻纤粉进行预处理可进一步改善复合材料的耐热性能。 相似文献
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Shuai Wang Fukai Yang Wei Sun Xinyu Xu Yuyuan Deng 《Journal of the American Oil Chemists' Society》2023,100(7):561-577
Rigid polyurethane foam (RPUF) is prepared from petroleum-based polyols and isocyanate, which consumes a large amount of petroleum. To alleviate the consumption of petroleum, it is necessary to synthesize green and sustainable polyols. However, the greatest disadvantage of RPUF is its flammability. To reduce the risk of fire caused by RPUF, phosphorylated soybean oil polyol (Polyol-P) and phenyl phospho-soybean oil polyol (Polyol-PPOA) were synthesized by ring-opening reactions of epoxy soybean oil with phosphoric acid and phenylphosphonic acid, respectively. A flame-retardant RPUF was prepared via polymeric 4,4-diphenylmethane diisocyanate (p-MDI), which reacted after mixing Polyol-P and Polyol-PPOA with polyether polyol-330N in different proportions. Scanning electron microscopy (SEM) showed that the cell sizes of the RPUF-P and RPUF-PPOA increased first and then decreased and the cell number decreased first and then increased with the increase in the contents of Polyol-P and Polyol-PPOA. Mechanical property tests showed that the compressive strength of the RPUF-P4 reached 0.1 MPa, and the compressive strength of the RPUF-PPOA4 reached 0.07 MPa. The limiting oxygen index values of the RPUF-P4 and RPUF-PPOA4 were 20.9% and 24.3%, respectively. The UL 94 of the RPUFs indicated that the rating of the RPUF-PPOA3 was improved to V-1. The results showed that the flame-retardancy mechanism of the Polyol-P and Polyol-PPOA in the RPUF was based on the charred surface as a physical barrier, which slowed down the decomposition of RPUF and prevented heat and mass transfer between the gas and the condensed phase. 相似文献
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桐油与甘油在甲醇钠为催化剂的条件下发生醇解反应得到桐油醇解产物(GTO),GTO经环氧化得到环氧化桐油醇解产物(EGTO),EGTO与9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)发生开环反应生成新型含磷阻燃型桐油基多元醇(PTOP)。PTOP部分取代聚醚多元醇(PPG4110)与异氰酸酯及助剂反应,通过一步法制备聚氨酯硬泡(RPUF)。采用万能试验机、热导率测定仪、热重分析仪和锥形量热仪分别考察RPUF的力学性能、热稳定性和燃烧行为。结果表明:随着PTOP替代石油基多元醇的比率增大,RPUF的压缩强度、密度、热导率先增大后减小,热稳定性提高,极限氧指数(LOI)由18.1%提高至26.0%,而总放热量先减小后增大,这主要是由于PTOP结构中的DOPO基团具有阻燃作用而PTOP结构中含有的桐油基脂肪链易于燃烧且热释放量较大。以上结果表明PTOP部分取代PPG4110制备的RPUF具有良好的阻燃性能和热稳定性。 相似文献
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将中等羟值聚醚多元醇、低羟值聚醚多元醇、聚合物多元醇和苯酐聚酯多元醇分别与基础聚醚多元醇复配,制备了全水发泡硬质聚氨酯泡沫塑料,研究了4种不同组合多元醇对制品力学性能的影响,发现低羟值多元醇的加入使泡孔直径明显减小;过低羟值的TMN3050的加入对力学性能的提高不利;TMN700使泡沫体的压缩强度略为增加,冲击强度大幅提高,弯曲强度略为下降;聚合物多元醇TPOP36/28在低添加量下,制得硬泡泡孔直径明显减小,压缩强度和冲击强度大幅增加,弯曲强度降低;苯酐聚酯多元醇PS400A ,使泡孔直径减小,制得硬泡的密度和力学性能大幅降低。 相似文献