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木素—聚醚型聚氨酯的合成与性能 总被引:12,自引:0,他引:12
利用低污染的氧碱制方法制取的麦草氧碱木素合成了木素-聚醚型聚氨酯,对其热性能、力学性能进行了研究。结果表明,麦草氧碱木素可取代部分聚乙二醇与二苯甲基二异氰酸合成木素-聚醚型聚氨酯;异氰酸指数和木素含量对合成的木素-聚醚型聚氨酯性能有影响。 相似文献
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聚氨酯慢回弹块状泡沫的研制 总被引:1,自引:0,他引:1
以慢回弹泡沫用聚醚LW-1080和普通软泡聚醚ZS-2802为主原料,制备了聚氨酯慢回弹块状泡沫,讨论了催化剂、硅油、发泡剂、开孔剂及TDI指数对发泡工艺及泡孔结构的影响,并与国内外同类慢回弹聚醚进行了比较.结果表明,复合催化剂胺与锡用量在0.35∶0.06~0.45∶0.10份之间、硅油B-8002的用量在1.0~1.8份之间、发泡剂水的用量在1.5~2.5份之间、开孔剂SK-1900用量在1.5~2.5份之间、TDI指数为80~95时,慢回弹聚氨酯泡沫具有较好的发泡工艺及泡孔结构;LW-1080慢回弹聚醚与国内外同类产品性能相当. 相似文献
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以低含氢硅油、α-烯丙基聚醚等为原料,经烷基封端、硅氢加成等反应制备了封端型聚醚改性聚硅氧烷非离子表面活性剂,讨论了温度、催化剂以及聚醚结构等对封端率的影响。结果表明,采用以氢氧化钠和碳酸钠制备的缓释性复合碱为催化剂的一步法封端工艺,在反应温度25~65℃条件下,α-烯丙基聚醚的烷基封端率可达85%以上。封端型聚醚改性有机硅表面活性剂可用于单组分聚氨酯密封胶、高回弹和软质聚氨酯泡沫的泡沫稳定剂。 相似文献
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采用异氰酸酯TDI和二元、三元聚醚多元醇合成高固体分的端异氰酸根的聚氨酯预聚物,选用不同结构的硅烷偶联剂和异氰酸根反应,制备部分或完全硅烷封端的湿固化聚氨酯弹性体。试验考察了不同的硅氧烷偶联剂以及用量对改性后聚氨酯弹性体合成及其性能的影响。 相似文献
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采用HFC-365mfc和H2O作为混合发泡剂制备了聚氨酯硬质泡沫材料,探讨了多亚甲基多苯基多异氰酸酯(PAPI)的官能度和异氰酸酯指数(R)对泡沫材料的玻璃化转变温度(Tg)、力学性能和泡孔结构的影响。结果表明,使用相同份数的发泡剂,在PAPI的官能度介于2.6~3.1范围内,官能度越高,所得泡沫密度越大、Tg越高,力学性能越好;当R介于1.05~1.50时,随R的增大,所得泡沫密度增加,Tg和力学性能均有提高,但当R过大时,泡孔的尺寸分布变宽,均一性变差。研究还发现,所得泡沫Tg和力学性能随熟化时间延长亦有所提高。 相似文献
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聚异氰脲酸硬质泡沫材料是由PM-200(异氰酸酯和二苯甲烷二异氰酸盐的混合物)、异氰脲酸苯酐聚醚酯多元醇(IPPEP)或聚环氧丙烷多元醇在异氰酸酯指数为200的情况下制备的。考察了IPPEP对泡沫材料的热稳定性和阻燃性能的影响,并讨论了n(PO)∶n(PA)对IPPEP基泡沫材料力学性能的影响。结果表明:IPPEP的使用使聚氨酯泡沫材料的玻璃化转变温度提高了45℃,热分解温度由510℃提高到540℃,氧指数提高到23.3%。随着n(PO)∶n(PA)的降低,泡沫材料的拉伸强度和压缩强度呈现先增加后降低的趋势。 相似文献
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分别以不同异氰酸酯、端羟基聚二甲基硅氧烷(HTPDMS)、聚四氢呋喃醚二醇(PTMG2000)和扩链剂等为原料,采用半预聚法工艺制备了有机硅链段改性的低压缩永久变形(LCS)聚氨酯微孔弹性体(MPU)。探讨了预聚物类型、扩链剂类型、HTPDMS添加量、R值、硬段含量等因素对MPU力学性能特别是30%压缩永久变形(70℃、22 h)的影响。结果表明,采用液化MDI为异氰酸酯组分、自制902为扩链剂、R值为1.05、硬段质量分数为22%、软段中HTPDMS质量分数为15%时,压缩永久变形为1.8%,满足LCS要求。 相似文献
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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 相似文献
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C. S. Lee T. L. Ooi C. H. Chuah S. Ahmad 《Journal of the American Oil Chemists' Society》2007,84(12):1161-1167
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. 相似文献
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以水稻秸秆液化产物为原料,以N,N,N,N,N-五甲基二乙烯三胺(P5)和N,N-二甲基环己胺(P8)为复合催化剂,制备了全水发泡聚氨酯泡沫(PUF)材料。通过调节水用量、催化剂比例、异氰酸酯指数及泡沫稳定剂用量,对不同条件下制备的泡沫性能进行测试,确定较优的制备工艺。利用万能试验机、热重分析仪(TGA)、傅里叶变换红外光谱仪(FT-IR)和扫描电子显微镜(SEM)对PUF的力学性能、热稳定性、结构和表观形貌进行了测试和表征。结果表明:当发泡剂水的用量为2%,催化剂P5/P8用量2%、催化剂P5/P8质量比值为1.5,异氰酸酯指数为1.2,硅油B8462用量为4%时,制得的聚氨酯泡沫性能最佳,密度为40 kg/m3、拉伸强度为309 kPa、压缩强度为154 kPa,其力学性能优于以有机锡和叔胺类化合物为催化剂制备的水稻秸秆PUF,且具有较好的热稳定性。 相似文献
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Bamboo residues were liquefied by using a solvent mixture consisting of polyethylene glycol 400 and crude glycerol (4/1, w/w) with 98% sulfuric acid as catalyst at 160°C for 120 min. The liquefied bamboo had hydroxyl values from 178 to 200 mg KOH/g and viscosities from 507 to 2201 mPa S. The obtained bamboo‐based polyols were reacted with various amounts of polyaryl polymethylene isocyanate (PAPI), using distilled water as blowing agent, silicone as surfactant, and triethylenediamine and dibutyltine dilaurate as cocatalyst to produce semirigid polyurethane (PU) foams. The [NCO]/[OH] ratio was found to be an important factor to control the mechanical properties of PU foams. At a fixed [NCO]/[OH] ratio, both density and compressive strength of PU foams decreased with the increase of bamboo content. The microstructure of PU foams indicates that [NCO]/[OH] ratios are important for cell formation and chemical reactions. The uniformity and cell structure of the foams are comparable to their corresponding compressive strengths. Moreover, the thermogravimetry analysis showed that all the semirigid PU foams had approximately the same degradation temperature of about 250 to 440°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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采用二乙醇胺、自制四溴双酚A环氧树脂(E-21)为原料合成了阻燃聚醚多元醇组分;采用2,4-甲苯二异氰酸酯(TDI)、聚乙二醇(PEG)、三羟甲基丙烷(TMP)为原料,在二月桂酸二丁基锡的作用下,通过逐步聚合反应得到异氰酸酯组分;将两组分按一定比例进行发泡得到阻燃聚氨酯硬质泡沫塑料。利用热重分析仪、水平燃烧测定仪等手段进行了表征,研究了异氰酸酯指数、发泡剂以及阻燃剂对聚氨酯硬质泡沫塑料性能的影响。结果表明,与不添加阻燃剂的聚氨酯硬质泡沫塑料相比,阻燃聚氨酯硬质泡沫塑料的吸热峰温度从294.8℃提高到303.8℃。 相似文献