聚氨酯/蒙脱土纳米复合材料性能研究

将聚氨酯的单体插层于蒙脱土中 ,经过多元醇与异氰酸酯的聚合反应制备聚氨酯 /蒙脱土纳米复合材料。研究结果表明蒙脱土纳米材料不仅提高了聚氨酯的模量 ,同时又使其强度不下降 ,密度不增大。     

原位乳液插层法制备丁腈橡胶/蒙脱土纳米复合材料的研究

结合乳液插层蒙脱土的特点，利用原位插层制备了丁腈橡胶（NBR）／改性蒙脱土（HOMMT）纳米复合材料。通过X-射线衍射（XRD）及透射电镜（TEM）证实和分析了蒙脱土的纳米分散相结构。物理性能的研究表明，所制备的复合材料体现了纳米材料的一些特点，填充少量蒙脱土，复合材料的物理机械性能即达到一个较高的水平。     

纳米蒙脱土插层聚氨酯改性环氧彩色地坪涂料的研制

采用聚氧化丙烯二醇(N-210)，甲苯二异氰酸酯(TDI)、有机纳米蒙脱土等为原料，制备了有机蒙脱土纳米插层聚氨酯预聚体，并以此对环氧树脂E-44进行化学改性，根据改性复合材料的力学性能等确定了纳米插层聚氨酯预聚体与环氧树脂配量范围，并以纳米插层聚氨酯改性的环氧树脂为基料，确定了地坪涂料各组分的最佳用量范围，研制出了一种高性能纳米插层聚氨酯改性环氧彩色地坪涂料。     

纳米插层聚氨酯改性环氧树脂性能研究

采用聚氧化丙烯二醇(N210和N220)、2，4-甲苯二异氰酸酯(TDI)、有机纳米蒙脱土(OMMT)等为原材料，分别制备了相应的聚氨酯预聚体和有机蒙脱土纳米插层聚氨酯预聚体，并以此对环氧树脂E44进行化学共聚改性，系统地研究了改性环氧树脂复合材料的力学性能等。研究表明，有机蒙脱土纳米插层聚氨酯能大幅度提高环氧树脂复合材料的韧性等，比相应的聚氨酯预聚体改性环氧树脂具有更好的效果。     

蒙脱土/聚氨酯复合材料的制备与阻燃性能的研究

研究了蒙脱土/聚氨酯复合材料的阻燃性能,分别从蒙脱土种类、插层温度、插层时间、蒙脱土的用量、复合材料密度等因素,考察了其对蒙脱土/聚氨酯复合材料阻燃性能的影响。利用垂直燃烧法观察火焰高度、燃烧时间的差别。结果表明:采用有机改性纳米蒙脱土,插层温度为100℃、插层时间为4 h、蒙脱土用量为40%,制备而成的蒙脱土/聚氨酯复合材料阻燃性能最佳,燃烧时火焰高度最低,燃烧时间为29 s后自熄。     

PU/OMMT纳米复合材料的制备与性能研究

采用单体插层聚合方法制备聚氨酯（PU）／有机蒙脱土（OMMT）纳米复合材料,并对其结构和性能进行分析。结果表明，经双羟乙基十二烷基三甲基氯化铵改性得到的OMMT（DK2）层间距较大；DK2质量分数为0．03时,PU／OMMT纳米复合材料中OMMT剥离程度较大，PU的插层效果较好,复合材料的物理性能和热稳定性能优良。     

PVC/聚烯烃/蒙脱土纳米复合材料的制备与性能研究

将钠基蒙脱土(MMT)预先负载小分子单体丙烯酰胺(AM)和引发剂过氧化二异丙苯，然后与PVC／PE或PVC／PP在双辊上进行插层复合，制成了PVC／聚烯烃／蒙脱土纳米复合材料，对复合材料进行了表征。结果表明：吸附丙烯酰胺后蒙脱土的层间距有所增大，AM-MMT填充的复合材料属于插层型纳米复合材料，PP复合材料比PE复合材料更容易插层蒙脱土；纳米复合材料的拉伸强度和冲击强度都随AM-MMT用量的增加有一最大值；DSC显示插层效果较好的纳米复合材料的Tg较低。     

SBS纳米复合材料的制备研究现状

介绍目前国内外SBS纳米复合材料的研究现状，重点介绍用蒙脱土和白泥制备SBS纳米复合材料的原理和方法，包括蒙脱土和白泥的精制改性、蒙脱土与高聚物的复合方法、复合熔融插层法和溶液插层法蒙脱土／SBS纳米复合材料的制备以及改性白泥和改性纳米层状白泥／SBS纳米复合材料的制备。指出制备耐热聚合物纳米粒子对SBS进行填充改性或采用纳米复合技术在SBS中引入纳米无机相进行增强反应是SBS纳米复合材料的研究方向。     

聚合物/层状硅酸盐纳米复合材料的制备研究

本文以聚丙烯和有机蒙脱土为原料，采用插层复合法制备聚合物／层状硅酸盐纳米复合材料，用透射电镜对复合材料的结构进行表征，测定了复合材料的力学性能，结果表明，用马来酸酐化聚丙烯作界面相容剂，聚丙烯大分子链分子插层进入到有机改性蒙脱土的硅酸盐片层中间，并且聚丙烯／蒙脱土纳米复合材料的力学性能有一定的提高。     

专利专栏

专利名称:聚氨酯弹性体／蒙脱土纳米复合材料及其制备方法专利申请号:02129016.4公开号:1398921申请人:中国科学院长春应用化学研究所本发明属于聚氨酯弹性体／蒙脱土纳米复合材料及其制备方法。这类聚氨酯弹性体／蒙脱土纳米复合材料由聚氨酯弹性体、增容剂、有机化蒙脱土和功能性防老剂组成。其制备方法是将蒙脱土经过阳离子交换反应后,再与增容剂进行熔融插层,并借助增容剂增容聚氨酯弹性体和有机化蒙脱土。本发明的纳米复合材料不仅具有蒙脱土均匀分散在聚合物基质中的结构,而且力学性能相对于纯聚氨酯弹性体有明显提高。     

Nanofilled polyols for viscoelastic polyurethane foams

The use of polyether polyols is common in polyurethane industry, particularly in soft PU applications. In particular, viscoelastic foams, characterized by slow recovery after compression, are obtained using poly(ethylene oxide) (PEO) polyols. Nanofilled polyols can be used for the production of viscoelastic foams with improved fire resistance properties. The high polarity of polyether polyols is responsible of a poor affinity with the organic modifiers used in commercial organically modified montmorillonite (omMMT). In this work, organically modified montmorillonites were prepared, having an improved affinity with the polyether polyols used for the production of soft PU foams. The montmorillonite was modified by using polyetheramines with different ethyleneoxide/propyleneoxide amounts. A strongly intercalated/exfoliated structure was obtained after mixing the polyol with the omMMT. The viscosity increased by three orders of magnitude and the diffraction angles of the MMT measured by x‐ray analysis decreased to values lower than 1.5°. The intercalated structure was preserved after the curing stage, when the isocyanate was added to the polyol/omMMT. The resulting polyurethane had an irregular open cell structure, and was characterized by a mechanical properties comparable to those of unfilled polyurethane. Copyright © 2009 Society of Chemical Industry     

熔纺氨纶用封闭型聚氨酯加成物的研制

讨论了用于熔纺氨纶的封闭型聚氨酯加成物的合成,研究了反应条件对封闭剂和-NCO基反应的影响.封闭加成物在空气中贮存稳定性好,并能在适当条件下重新生成-NCO基.     

桐油基聚氨酯的制备及性能研究

以桐油基酸酐和丁二醇为原料通过酯化及酯交换反应合成了桐油基多元醇,并进一步以制备的桐油基多元醇和/或聚丙二醇为羟基组分,与异佛尔酮二异氰酸酯反应制备了桐油基聚氨酯.考察了桐油基聚氨酯的耐水性、耐醇性和漆膜硬度,并讨论了桐油基多元醇和聚丙二醇比例对聚氨酯性能的影响.结果表明桐油基多元醇可提高漆膜硬度、耐水性及耐醇性.     

Kinetics and mechanism of isocyanate reactions. II. Reactions of Aryl Isocyanates with Alcohols in the presence ob tertiary amines

The reaction of phenyl isocyanate with n-butanol in the presence of tertiary amines has been kinetically studied as a model process for the polyurethane formation under conditions similar to those of industrial scale production. The rate-determining step is believed to be the nucleophilic attack of tertiary amine on an associate of isocyanate with alcohol which is then converted into a very reactive uronium salt. This salt reacts fast with alcohol giving the final product, the urethane.     

Preparation and characterization of an epoxy resin modified by a combination of MDI‐based polyurethane and montmorillonite

The present work investigates the modification of epoxy resin by using a combination of nanoclay (montmorillonite—Cloisite 30B) and a liquid polymeric modifier (polyurethane). Polyurethane was obtained from 4,4′‐diphenylmethane diisocyanate and polydiols with different molecular weight: polyethylene glycol (PEG 400) and polyoxypropylene diols with molecular weight 1000 g/mol and 2000 g/mol. The impact strength, the critical stress intensity factor as well as the flexural strength were evaluated as functions of modifiers content. The obtained results showed that hybrid composites exhibit enhanced mechanical properties without significant changes of the glass transition temperature. FTIR analysis showed that chemical reactions took place between the hydroxyl groups of epoxy resin and the isocyanate groups of polyurethane, explaining an improvement of the mechanical properties of epoxy resin. However, XRD results demonstrated the formation of an exfoliated structure for the hybrid compositions with both polyurethane and montmorillonite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

水性聚氨酯/蒙脱土复合乳液的合成及性能表征

本文通过蒙脱土插层聚合法制备了水性聚氨酯/蒙脱土复合乳液。通过单体插层于蒙脱土中,与聚氨酯聚合反应,均匀分散于水性聚氨酯中。用FTIR和TEM测试表征,观察到蒙脱土均已聚合入聚氨酯包裹。研究结果表明:当蒙脱土含量在5%左右时,该乳液涂膜具有较好的耐热性、10%分解温度比普通聚氨酯提高了大约20℃,拉伸强度和断裂强度达到最高值,分别为2.31Mpa和17.94N/mm。随着蒙脱土含量的增大,乳液粒子粒径增大,耐水性增强。蒙脱土含量达到5%时,乳液粒径为108nm,吸水率降至31.9%。     

丙烯酸酯改性水性聚氨酯树脂合成工艺的研究

以异氰酸酯、聚醚多元醇及二羟甲基丙酸为主要原料,合成了水性聚氨酯预聚体(PU),并且经过扩链、交联、丙烯酸酯复合改性等反应制备了丙烯酸酯改性水性聚氨酯树脂(PUA)。结果表明:对水性聚氨酯进行扩链、交联及丙烯酸酯复合改性,可以使两者优异的性能有机地结合起来,能显著提高水性聚氨酯的拉伸强度、硬度、耐磨性、耐水耐醇性,从而使水性PUA分散乳液胶膜的性能得到明显改善,以满足水性PUA木器漆用的要求。     

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     

Novel polyurethane polyols for waterborne and high solids coatings

Recently developed oligomeric β-hydroxyalkyl urethane polyols are finding application as modifiers and crosslinkers for waterborne and high solids coatings. In waterborne coatings, urethane polyols can be used as modifiers for acrylic, polyester or alkyd melamine resin crosslinked coatings to replace the cosolvent. In high solids coatings, polyurethane polyols are being employed to raise the application solids, increase film hardness and water resistance, and exterior durability.

There are also applications for polyurethane diols as resin intermediates and in the preparation of blocked isocyanate crosslinkers. β-Hydroxyalkyl urethane diol or polyols can be prepared by an isocyanate reaction with a diol, such as 1,2-propylene glycol, but also by non-isocyanate processes. The non-isocyanate routes to urethanes can utilize carbon monoxide, carbon dioxide, urea or organic carbonates as a carbonyl source for the carbamic acid ester.

It is possible to split these urethanes to the isocyanate, but interest has concentrated on using the urethane intermediates directly in coating applications without going through the isocyanate. The structures reported are bis-hydroxyalkyl urethane intermediates and derivatives of these compounds.     

Kinetics and mechanism of isocyanate reactions. I. Reactions of Aryl Isocyanates with Alcohols

The reaction of aryl isocyanates with alcohols has been kinetically studied as a model reaction for polyurethane formation under conditions similar to those of industrial scale production. Considering the isocyanate and alcohol structure, kinetic isotopic effect, activation enthalpy and entropy and solvent effects it has been found that the most probable mechanism is the alcohol addition through a four-membered cyclic transition state.