全水发泡聚氨酯硬泡的开发

全水发泡聚氨酯硬泡的开发宋聪梅 童俊 罗振扬（江苏省化工研究所 江苏南京 210024）摘 要：探讨了影响全水发泡泡沫性能的相关因素，研制了具有良好流动性的全水发泡聚氨酯硬泡 组合聚醚。依此制备的硬质聚氨酯泡沫塑料具有良好的尺寸稳定性、优异的粘接性能和较低的导热系数， 已达到或超过汽车、建筑行业对全氟泡沫的要求，具有广阔的市场前景。关键词：聚氨酯；硬质泡沫塑料；全水发泡；聚醚多元醇硬质聚氨酯泡沫塑料是一种很重要的合成材料，具有优异的物理机械性能和耐化学性能，尤其是导 热系数低，是一种优质的隔热材料，广泛应用于冰箱、冷柜及汽车行业、建筑行业。但是由于氯氟烃（CFC） 发泡剂对大气臭氧层有破坏作用，为了维护生态环境，国际公约已经对其生产和使用做出了严格的限制 和规定。因此，聚氨酯工业面临的一个重要任务就是选择CFC的代用品，减少和停止CFC的应用。10 多年来，以零或低 ODP 值的发泡剂替代氯氟烃是聚氨酯泡沫塑料行业最重大的课题，促使泡沫塑料生产 技术发生重大变化。在聚氨酯硬泡中，常用的CFC-11替代发泡剂主要有HCFC-141b为代表的HCFC类发泡剂、以戊烷 为代表的烃类发泡剂以及水发泡剂1。以水作发泡剂，实际上是以水和异氰酸酯反应生成的co2气体作 发泡剂，其臭氧破坏效应 ODP 值为零，无毒副作用，因此水是最具吸引力的 CFC-11 最终替代物。而且， 全水泡沫制备工艺简便，对设备的要求很低，可沿用CFC-11体系的设备，具有广阔的市场前景。但是, 全水发泡体系与 CFC-11 体系相比存在许多不足，诸如组合聚醚粘度比较大，泡沫与基材的粘接性差、 导热系数偏高等，从而限制了全水发泡聚氨酯泡沫的推广和应用2。针对全水发泡体系的特点，我们通过聚醚分子结构的调整、助剂的选择，开发了低粘度的聚醚及具 有良好流动性的组合聚醚，以此制备的聚氨酯泡沫塑料具有良好的尺寸稳定性、粘接性和较低的导热系 数。1 实验部分1.1 主要原料PE600系列聚醚多元醇，自制；聚醚多元醇A,金陵石化公司化工二厂；聚醚多元醇TNR410，天 津第三石油化工厂；复合催化剂，自制；泡沫稳定剂AK-8805等，南京德美世创化工有限公司；泡沫稳 定剂B-8462、B-8433等，德国高施米特公司；多异氰酸酯（PAPI），日本聚氨酯工业公司。1.2 设备与仪器2.5L 多功能组合式聚合釜；微量水份分析仪；旋转式粘度计；恒温水浴箱；电动搅拌器， Glas-Craft 公司的高压喷涂发泡机。1.3 手工发泡将聚醚多元醇、泡沫稳定剂、催化剂、水等混合均匀，作为A组分；以多异氰酸酯作为B组分。 发泡时，调节A料、B料及模具的温度，按配方称取A、B料，混合后搅拌510 s，立即倒入模具使其 自由发泡，同时依次测定乳白、纤维、脱粘时间，待泡沫完全熟化后测定相关性能。1.4 组合聚醚典型配方组合聚醚：混合多元醇 100份；泡沫稳定剂 1.52.5份；复合催化剂 2.05.0份；水 3.0 4.0 份。异氰酸酯指数 1.01.1发泡时的工艺参数（室温20C）为：乳白时间1020 s,固化时间2035 s。2 结果与讨论2.1 聚醚多元醇对全水发泡泡沫性能的影响在聚氨酯硬泡的制备中，相对分子质量和官能度不同的聚醚或聚酯与异氰酸酯反应形成长短不一的 链段，形成相应的软硬段聚集态，构成泡沫的主体结构。选用聚醚的主要依据是泡沫制品的用途，性能 要求，工艺性能，原料价格等。由于全水发泡体系缺少大量的低粘度物理发泡剂的稀释与溶解作用，采 用现有高粘度硬泡聚醚的配方体系，其粘度大幅增加，混合与乳化过程变得困难，反应体系的流动性变 差。水与二氧化碳反应生成较多的脲键，使泡沫粘接性能下降；同时，由于二氧化碳从泡孔内向外扩散 速率大于空气向泡孔内的扩散速率，使泡孔内压力降低，导致泡沫收缩，尺寸稳定性降低3。因此，全 水发泡硬质聚氨酯泡沫技术的关键在于开发新型的低粘度、高性能硬泡聚醚多元醇。表 1 为采用几种聚 醚多元醇配制的组合聚醚的粘度及其制得的泡沫塑料的物性。本稿中体积变化率取绝对值，下同。表1聚醚品种对全水发泡泡沫性能的影响组合聚醚IIIJDPU303主体聚醚TNR410聚醚APE600组合多元醇粘度(25C)/mPas175023001200泡沫密度/kg m-335.837.438.8压缩强度/kPa254256293拉伸强度/kPa300323393导热系数/W(mK)-10.02580.02630.0255吸水率/变形3.42.3高温体积变化率(80 Cx24h)/ %0.40.40.3低温体积变化率(一25Cx24h) /%0.50.30.2以脂肪族聚醚多元醇TNR410为主体聚醚的组合聚醚I,其原液的粘度明显偏大，在常温及低温环 境下，发泡设备无法正常工作，需要对原液加热以降低其粘度；并且，由表1可见，以TNR410合成的 硬质聚氨酯泡沫塑料易吸水变形。以聚醚A合成的硬质聚氨酯泡沫塑料，其物性虽然符合技术标准，但 以其为主体聚醚的组合聚醚的粘度严重超标，即使在夏季也需要对其进行预热才能满足发泡设备的使用 要求。采用聚醚PE600配制组合聚醚，不仅降低了组合多元醇的粘度，使其满足普通发泡设备的使用要 求，而且，以 PE600 合成的全水发泡硬质聚氨酯泡沫塑料具有良好的物理性能。2.2 异氰酸酯指数对硬质聚氨酯泡沫性能的影响在硬质聚氨酯泡沫塑料的合成中，异氰酸酯指数通常大于 1.0，使反应过程中有过量的异氰酸酯基 团与氨基甲酸酯进行次级反应，生成脲基甲酸酯；同时异氰酸酯基团自身之间进行三聚反应，生成异氰 脲酸酯，这两种链段结构的存在使硬质聚氨酯泡沫塑料具有较高的压缩强度和尺寸稳定性。发泡时的异 氰酸酯指数与水发泡硬质聚氨酯泡沫塑料压缩强度和拉伸强度的关系见图1。图 1 异氰酸酯指数对泡沫塑料强度的影响由于水发泡体系硬质聚氨酯泡沫塑料中已经存在大量刚性的聚脲链段，随着异氰酸酯指数的增加， 泡沫塑料的脆性也相应增加，这就导致泡沫塑料韧性下降，拉伸强度下降。异氰酸酯指数对全水发泡聚氨酯泡沫塑料的影响见图 2。由图2可见，异氰酸酯指数增加，则交联度增加且刚性增加，高温和低温体积变化率均降低，说明尺寸稳定性增加。%、芒超黑址1高温(80Cx24h)尺寸稳定性2低温(一25Cx24h)尺寸稳定性图 2 异氰酸酯指数对泡沫塑料尺寸稳定性的影响2.3 水含量及密度对硬质聚氨酯泡沫塑料性能的影响组合聚醚中水的用量增加，与异氰酸酯反应生成更多的co2,放出更多的热量，使得泡沫密度降低。 密度的变化对泡沫塑料的性能有较大的影响。2.3.1 水含量及密度对泡沫尺寸稳定性的影响 全水发泡泡沫塑料体系随着水用量的增加，密度降低，形成更多的开孔结构，这不仅降低了泡孔壁 的强度，也加速了 CO2气体的扩散，从而影响泡沫的尺寸稳定性，见图3。1 高温(80Cx24h)尺寸稳定性2低温(一25Cx24h)尺寸稳定性图 3 密度对泡沫塑料尺寸稳定性的影响2.3.2 水含量及密度对泡沫导热系数的影响 闭孔型硬质聚氨酯泡沫塑料的泡孔孔径很小，其导热系数主要取决于泡孔内气体的导热系数、树脂固体的导热系数及辐射传热导热系数，而气体的导热系数占泡沫导热系数的 60以上，因此泡沫内绝热气体的含量将是影响泡沫整体导热系数的关键。在泡沫密度大于30 kg/m3时,树脂固体的导热系数基本固 定，而辐射传热导热系数影响很小的情况下，水分的增加将使泡沫密度降低，这有利于提高泡沫的初始 绝热性能，见图 4。图 4 密度对泡沫塑料导热系数的影响2.4 交联剂对硬质聚氨酯泡沫塑料物性的影响 交联剂是聚氨酯泡沫塑料中一类比较常用的配合剂，一般为小分子的多元醇、多元胺或它们的环氧 化物加成物。添加少量的交联剂可以提高聚氨酯泡沫的交联密度及闭孔率，增强泡沫的抗压强度、耐渗 透性，表 2 比较了相同配方的情况相同用量的情况下，不同交联剂对硬质泡沫塑料物性的影响。表 2 交联剂对硬质聚氨酯泡沫塑料物性的影响交联剂品种甘油三乙醇胺CLA-1CLA-2无父联剂压缩强度/kPa253254280293177吸水率/%变形变形3.32.3变形2.5 表面活性剂的选择 在全水发泡硬质聚氨酯泡沫发泡体系中，由于使用极性较强的水作为化学发泡剂导致发泡体系的极 性增加。传统的甲基硅氧烷氧化烯烃共聚物表面活性剂的极性较强，因而它对同样呈强极性的全水硬质 聚氨酯泡沫发泡体系的乳化成核作用相对较弱，难于形成细密、均匀的闭孔结构泡沫。非水解硅酮表面活性剂是为全球范围内聚氨酯泡沫塑料CFC及HCFC替代的趋势而开发的高活性 表面活性剂。2.5.1 表面活性剂对泡沫导热系数的影响B8433 非水解硅酮表面活性剂是德国高施密特公司专门开发的全水发泡硬质聚氨酯泡沫表面活性剂，它对水聚醚多元醇异氰酸酯体系有着优异的乳化成核能力，在反应过程中控制泡孔结构，并最 终获得泡孔细腻均匀、绝热性能良好的硬质聚氨酯泡沫塑料。本工作在相同的主配方体系中分别采用不 同的用量的不同的有机硅表面活性剂（泡沫稳定剂），制得的泡沫塑料的导热系数见图 5。2.5.2 表面活性剂用量对泡沫尺寸稳定性的影响 随着表面活性剂用量的增加，硬质聚氨酯泡沫塑料的泡孔结构更趋向于均一化，闭孔率增加，其尺寸稳定性也相应提高，高温尺寸稳定性的改善尤为明显，见图 6。2.6 催化剂的选择在全水发泡聚氨酯发泡体系中，传统的叔胺催化剂如N,N-二甲基环己胺、三亚乙基二胺、二甲基乙 醇胺等主要促进异氰酸酯与水之间生成聚脲和co2的发泡反应，而对凝胶反应的促进作用较弱。为了调 节发泡与凝胶之间的平衡，可以配合使用三嗪类催化剂、碱金属盐等凝胶催化剂，改善全水泡沫的脆性 增强其对基材的粘结力。O925 O8- & 7 7 6- 62 224.5 -II II II II II I I II II II I1.41.61.82.02.22.42.62.83.03.2质量份/100份多元醇1B8433 2B8462 3AK8805 4L6900图 5 表面活性剂品种和用量对泡沫导热系数的影响1低温(一25Cx24h)尺寸稳定性2高温(80Cx24h)尺寸稳定性图 6 泡沫稳定剂 B8433 用量对泡沫尺寸稳定性的影响3 全水发泡硬质聚氨酯泡沫塑料3.1 全水发泡泡沫原液多元醇组分的理化性能指标 全水发泡泡沫原液组合聚醚的理化性能指标见表 3。表3全水发泡泡沫原液组合聚醚的理化性能指标牌号JDPU303外观棕色羟值/mgKOHg140030酸值/mgKOHg10.5水分/3.50.5粘度(25C)/mPa s1100300pH值911将组合聚醚 JDPU303 和多异氰酸酯组分混合、搅拌，立即倒入模具使其自由发泡，待泡沫完全熟 化后测定相关性能。表4列出了自制全水发泡聚氨酯硬泡的性能以及有关汽车行业、建筑行业(B类)用硬质聚氨酯泡沫塑料的性能指标。可以看出自制全水发泡聚氨酯泡沫的各项性能指标均已达到或超过有关标准中对汽车、建筑行业用CFC-11发泡聚氨酯泡沫塑料的性能要求。表4t制全水发泡泡沫与汽车行业.建筑行业MCFC-11体系聚氨酯硬泡的性能指标比较泡沫种类JDPU303JDPU303-N汽车(FIAT9.55257)建筑(GB10800-B 类)密度/kg m-338.8（芯密度）43.5（整体密度）455 （整体密度）三30压缩强度/kPa293317-三100拉伸强度/kPa393521-导热系数/mW(mK)-125.626.42727吸水率/2.33.9W44体积变化率/25 C 24h0.20.10.2(-20C 24h)-80 C 24h0.330.60.55(70C 48h)水平燃烧速率/mm min-1-86100-粘接性粘接力大于内聚力粘结力大于内聚力粘接力大于内聚力-注：JDPU303-N为阻燃型全水泡沫。FIAT9.55257是意大利FIATO汽车公司的标准。4 结束语全水硬质聚氨酯泡沫塑料，不仅应用于 IVECO 车身及冷库、屋顶、大棚等建筑物的喷涂，还用于 管中管、夹心板材等的生产5。全水泡沫的推广应用，可以彻底淘汰消耗臭氧层物质，使聚氨酯工业成 为真正清洁、安全、有效的产业，加快我国氟氯烃取代的进程，促进我国聚氨酯工业赶上国际先进水平。参考文献1 Roux J D等.HCFC-141b现状及HFCs最新进展.见:聚氨酯中国95国际会议论文集,41442 李绍雄,刘益军.聚氨酯树脂及其应用,1831913 Fishback T L, etc. Polyol Composition Good Flow And Water Blown Rigid Polyurethane Foams Made Thereby Having Good Dimensional Stability. USP 5686500（1997）4 Rotermund U, etc.降低烃类发泡的硬质聚氨酯泡沫塑料导热性.见:聚氨酯中国95国际会议论文 集,49575 Kellner J, Evans D, 沈嵘. 聚氨酯预制隔热管的生产技术和用于集中共热管道高质量的聚氨酯泡沫系 统.见:中国聚氨酯工业协会第十次年会论文集102108Preparation of Water-Blown Rigid Polyurethane FoamsSong Congmei Tong Jun Luo Zhenyang(Jiangsu Institute of Chemical Industry, Jiangsu Nanjing 210024)Abstract: The water-blown rigid polyurethane foam systems with good flow were prepared. The related factors effecting on the foaming properties are discussed. The rigid foam has good dimensional stability, excellent adhesion and lower thermal conductivity. The properties of the foam can reach or surpass the specification requirement for automobile and construction industry. The water-blown polyurethane system products have good market prospect.Keywords: polyurethane; rigid foam; water-blown; polyether polyol作者简介：宋聪梅 高级工程师，1989年毕业于南京大学化学系，主要从事聚酯、聚醚及聚氨酯材料的研制开发。Preparation of Water-Blown Rigid Polyurethane FoamsSong Congmei Tong Jun Luo Zhenyang(Jiangsu Institute of Chemical Industry, Nanjing 210024)Abstract: The water-blown rigid polyurethane foam systems with good flow were prepared. The related factors effecting on the foaming properties are discussed. The rigid foam has good dimensional stability, excellent adhesion and low thermal conductivity. The properties of the foam can reach or surpass the specification requirement for automobile and construction industry. The water-blown polyurethane system products have good market prospect.Keywords: polyurethane; rigid foam; water-blown; polyether polyolPolyurethane rigid foam is a kind important synthetic material having good mechanical properties and chemical resistance and low thermal conductivity, which is a fine insulation material and used to refrigerators, freezers, automotive industry and building. In a move to reduce or eliminate ozone-depleting blowing agents from the manufacture of polyurethane foams, much effort has gone into investigating substitute of chlorofluorocarbons with low or zero ODP, which promote important innovation of polyurethane foam technology.In the PU rigid foam, the main replacements of the widely used blowing agents CFC-11 are HCFC-141b which is the representative blowing agent for HCFC systems, pentane which is the representative for hydrocarbon blowing agent and water blowing agent. In water blowing process, water reaction with isocyanate produce carbon dioxide gas, which is the real blowing agent in the reaction. Carbon dioxide gas is nonpoisonous and its ODP value is zero, so water is one of the most attractive final replacement of CFC-11.1. EXPERIMENTAL1.1 Main Materialspolyether PE600, self-made; polyether A, Jinling Petrochemical Ltd. Corp. No2 chemical Plant; polyether TNR410, The Third Petrochemical Factory; catalysts ，self-made; foam stabilizers AK-8805, Dearmate Shichuang Chemical Co.,Ltd.; foam stabilizers B-8462、 B-8433 etc, TH. Goldschmidt AG; PAPI, Nippon Polyurethane Industry Co., Ltd.1.2 Equipment and Devices2.5L multifunction polymerizer; water content analyzer; rotary viscometer；constant temperature water bath ； motor stirrer; high pressure spray machine 。;1.3 Process of Handing FoamAll components that will not react with each other, for example, polyol, blowing agents, catalysts and water, are weighed and premixed as part A; The isocyanate is regarded as part B. The part B is added in the part A and mixed intensively. The reaction mixture must be poured into the mold before reaching the cream time and can rise freely. After curing, the foamsproperties are obtained by standardized test methods.1.4 Typical FormulaPolyol competent 100; blowing agents 1.52.5; catalysts 2.05.0; water 3.04.0.Isocyanate Index: 1.01.1.Process parameter(20 C): cream time 1020s; curing time 2035s.2 DISCUSSIONS2.1 Effect of polyether on Properties of PU Rigid FoamsIn the process of PU rigid foams, polyether or polyester with a variety molecular weigh and functionality react with isocyanate to form polyurethane linkages, which gather to form the PU foam s soft segment and rigid segment. The polyether is added into polyol composition by the appliances and properties of PU rigid foam, manufacturing process and material price. Using water as a blowing agent has been found problematic. Water does not have the solvency that some CFC s and HCFC s possess leading to a poorer flowing liquid reaction mixture. The isocyanate reaction with water rapidly develops much urea linkages so that the foam becomes brittle and has low adhesion to a substrate. Also, carbon dioxide gas blowing the reaction mixture produced form the isocyanate/water reaction tends to diffuse out of the foam cells, leading to foam shrinkage. In an attempt to alleviate these problems, the highly functional low viscosity polyether should be added to a polyol composition. Table 1 shows the effect of a variety polyether on properties of water blown PU rigid foam.Table 1. Effect of a variety polyether on properties of PU rigid foamPolyol compositionII IJDPU303Main polyetherTNR410Polyether APE600Viscosity of polyol composition at 25 C /mPa s175023001200Density/kg m-335.837.438.8Compressive Strength/kPa254256293Tensile Strength /kPa300323393Thermal Conductivity /W (m K)-10.02580.02630.0255Water absorption /Out of shape3.42.3Dimensional stability at high temperature (80 Cx24h)/%0.40.40.3Dimensional stability at low temperature ( 25Cx24h) /%0.50.30.2Polyol composition I and II, which is mainly composed of polyether TNR410 and A, have too highly viscosity to satisfy foam machine at low temperature, further the PU rigid foam made of I is out of shape after immersed in water. Polyol composition JDPU303 composed of polyether PE600 not only has lower viscosity to attain usual foam machines request, but also has good mechanical properties.2.2 Effect of Isocyanate Index on PU Rigid FoamIn the manufacturing of rigid PU foam, additional isocyanate not only reacts with the urethane and the ureas producing allophanates and biurets, but also trimerize with themselve to form polyisocyanate, thereby improving the foam compressive strength and dimensional stability. Fig.1 shows the dependence of the compressive and tensile strength on isocyanate index.ECPI/qtbu。上 sFig.1 Strength vs. NCO indexThere are a lot of polyurea linkages in the water blown PU rigid foams, which increase foam s brittleness. As the isocyanate index increases further the foam brittleness increases, thereby the toughness and tensile strength reduce.Fig. 2 shows effect of isocyanate index on properties of water blowing foams. As ioscyanate index increases further the crosslinking density and rigidity of foam increase, so the low or high temperature dimensional stability increases.1.6 P4-2q-8-64-21- 1- 1- Q Q n- Q %/gmuEqo UUIOAJOEJ1 high temperature(80 C x24h)2 low temperature( 25 x24h)1.001.051.101.151.20isocyanate index1 high temperature(80 C x24h)2 low temperature( 25 C x24h)Fig.2 Dimensional stability vs. NCO index2.3 Effect of Water Content on Properties of FoamMore water in polyol composition reaction with isocyanate develops a higher exotherm, leading to the lower foam density, which affects the properties of rigid foam.2.3.1 Effect of Water Content on Dimensional Stability of FoamAs water content increases further foam density decreases, and more open-cells are formed, which reduce cell wall strength and improve the diffusion of carbon dioxide gas, leading to foam low dimensional stability.(Fig.3)%、MUEqUUI-OAJO1 high temperature(80 C x24h)2 low temperature( 25 C x24h)Fig.3 Dimensional stability vs. density2.3.2 Effect of Water Content on Thermal Conductivity of FoamThe thermal conductance of the foam is a combination of several factors: thermal conductivity of the cell gas; thermal conductivity of the polymer matrix; convection of the cell gas; thermal radiation. As long as the water blown foam has fine cells, the thermal conductance is primarily due to the first two factors. As the density increases the thermal conductivity of cell struts goes up. This increase, however, is not directly proportional to the increase in density. (Fig.4)Fig.4 Thermal conductivity vs. density2.4 Effect of Crosslinker on Properties of FoamCrosslinkers are reactive polyfunctional compounds of low molecular weight when used with isocyanates, for example: glycerol, trimethylolpropane, glycol, polyamine and their derivatives. Crosslinkers are added to increase the crosslinking density and close cell content, thereby improving the foam strength and immersion resistance. Table 2 shows the dependence of compressive strength and water adsorption on a variety of crosslinker.Table 2. Effect of crosslinker on properties of PU rigid foamTypeGlyceroltriethanolamineCLA-1CLA-2No CrosslinkerCompressive Strength/kPa253254280293177Water absorption /Out of shapeOut of shape3.32.3Out of shape2.5 Selection of Surfactants2.5.1 Effect of Surfactants on thermal conductivityB8433 is an appropriate silicone-polyether made by TH. Goldschmidt AG for water blown PU rigid foam. Through its good emulsification ability, surfactants accomplish good mixing of polyether composition and isocyanate and strong support of nucleation, resulting in finer, more regular cell structure and low thermal conductivity. Fig.5 shows the dependence of thermal conductivity on type and content of surfactants (based on typical formulation).2.5.2 Effect of Surfactant Content on Dimensional StabilitySurfactants performance criteria were the shape of the cup foam, the cell structure, and the appearance of the foam surface. As surfactant content increases the cell structure tends to be more regular and fraction of closed cell increase, which improves foam dimensional stability obviously (Fig. 6)2.6 Selection of CatalystsIn the manufacturing of water blown PU rigid foam the tertiary amines mainly promote the foaming reaction. A triazine catalyst and metal compounds catalyst are applied to promote gel reaction, balance the foaming and gel reaction, thereby improving foam toughness and cohesion.05050505059- 8- & 7 7 6- 6- 5 5 422222222221.41.61.82.02.22.42.62.83.03.2dosage of B8433per 100 part polyols1B84332B8462 3AK88054L6900Fig.5 Effect of types and content of foam stabilizers on thermal conductivity90aooooooo%MUEqQUIOA4OEJ1.41.61.82.02.22.42.6dosage ofB8433per 100 part polyols1 low temperature( 25 C x24h)2high temperature(80C x24h)Fig.6 dimensional stability vs. content of B84333. WATER BLOWING PU RIGID FOAM3.1 Typical Properties of Water Blown Polyol CompositionTable 3. Typical properties of water blown polyol compositionTypeJDPU303AppearanceBrownHydroxyl number40030Acid number0.5Water content in ()3.50.5Viscosity 25 C ( mPa s )1100300pH911Table 4 shows properties of self-made water blown PU rigid foam and CFC-11 blown PU rigid foam used in automotive industry and building. The properties of the water blown foam can reach or surpass the specification requirement for automobile and construction industry.Table 4. Properties of self-made water blown PU rigid foam and CFC-11 blown PU rigid foam used in automotive industry and buildingTypeJDPU303JDPU303-NAuto(FIAT9.55257)Building (GB10800-B)Density in kg m-338.8(core density)43.5455三30Compressive Strength in kPa293317-三100Tensile Strength in kPa393521-Thermal Conductivity in25.626.42727mW (m K)-1Water absorption in 2.33.9W44Dimensional stability in 25 C 24h0.20.10.2(-20C 24h)-80 C 24h0.330.60.55(70C 48h)Horizontal burning speed-86cohesionadhesioncohesionadhesioncohesion-* JDPU303-N-flame resistant grade。4. CONCLUSIONIn applications where insulating properties are not essential but some structural support is required, a total replacement of CFC-11 by carbon dioxide, which means water, is completely possible. So the water blown PU rigid foam is not only applied to spray on automotive, refrigerated warehouses and house, but also used to manufacture preinsulated pipe and laminated panel. Popularizing of water blown technology will reduce or eliminate ozone-depleting material, make PU industry turn into a really safety, clean production, improve the replacement of chlorofluorocarbons in China.REFERENCES1 Jean-Denis ROUX etc. Update of HCFC-141b and New Development of HFCs. PU China 95, 41442 Li shaoxiong, Liu yijun, Polyurethane Resin and Its Applicant, 1831913 Fishback, Thomas L. etc. Polyol Composition Good Flow And Water Blown Rigid Polyurethane Foams Made Thereby Having Good Dimensional Stability. USP 5686500(1997)4 U. Rotermund etc. Thermal Conductivity of PU Rigid Foam Reducing Blowing Agents. PU China 95, 49575 Jurgen kellner etc. Manufacture Technology of PU Pre-insulated Pipe and PU Foam System Applied to Central Heat Supply Pipeline. PU China Conference 2000, 102108BIOGRAPHYSong Congmei, senior engineer, graduated from Nanjing University in 1989, engaged in development of polyester, polyether and polyurethane material.