聚醚聚氨酯／聚甲基丙烯酸甲酯互穿聚合物网络相容性的研究

用同步法合成了聚醚聚氨酯/聚甲基丙烯酸甲酯(PU/PMMA)互穿聚合物网络(IPN)。讨论了不同交联缠结程度对IPN形态及性能的影响,分析了影响IPN两网络相容性的热力学及动力学因素。增加网络的交联密度可有效地改善IPN网络间的相容性,同时,调节两网络生成速度基本同步,控制在热力学相分离发生前使两网络最大程度地互穿缠结,也能减小相分离的程度,改善IPN网络间的相容性。     

受阻酚改性PU/PBMA IPN材料阻尼性能的研究

以聚碳酸酯二醇(PC-2000)、二苯甲烷二异氰酸酯(MDI)为原料合成聚氨酯(PU)预聚体,再以PU预聚体、扩链剂、甲基丙烯酸丁酯(BMA)及引发剂在一定条件下反应制备了聚氨酯/聚甲基丙烯酸正丁酯(PU/PBMA)互穿网络聚合物(IPN)材料,并加入受阻酚AO-80进行功能化改性,分别采用热固化法和室温固化法制备了受阻酚AO-80改性的PU/PBMA IPN材料。讨论了固化方法、PU与PBMA的配比、受阻酚AO-80用量等对IPN材料阻尼性能的影响,通过动态机械热分析、热失重分析以及扫描电子显微镜对IPN材料的阻尼性能、热稳定性和微观形态结构进行表征。结果表明,热固法比室温固化法更有利于制备高性能阻尼材料;受阻酚AO-80的加入可以明显提高IPN材料的阻尼性能,并能够有效地拓宽阻尼温域;当PU与PBMA质量比为60/40、AO-80质量分数为28%时,所制备的IPN材料的阻尼性能最佳。     

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。     

受阻酚改性聚酯/聚醚胺型PU/P(MMA-St)IPN阻尼性能的研究

用一步法制备了受阻酚AO-80改性的聚酯/聚醚胺型聚氨酯/聚(甲基丙烯酸甲酯-苯乙烯)互穿聚合物网络(PU/P(MMA-St)IPN)。通过热失重分析仪、动态力学分析以及扫描电子显微镜对IPN材料的热稳定性、阻尼性能和微观结构形态进行了表征。研究结果表明:AO-80可以提高PU与P(MMA-St)的相容性,从而有效拓宽阻尼温域;当聚氨酯中聚酯/聚醚胺=80/20,w(AO-80)=20phr,PU/P(MMA-St)=70/30时,所得IPN材料的阻尼性能最佳。     

聚氨酯/环氧树脂互穿网络聚合物反应动力学

通过共混法制备了聚氨酯(PU)/环氧树脂(EP)互穿网络聚合物(IPN),采用示差扫描量热法(DSC)和动态机械分析(DMA)对IPN形成过程中的固化反应动力学及产物IPN的相容性进行了研究,结果表明,m(PU)/m(EP)=10∶6的IPN体系的反应级数为0.95,表观活化能为169.23 kJ/mol;PU/EP IPN只有1个玻璃化转变温度,相容性好。     

PDMS改性蓖麻油基水性聚氨酯的制备及防污性能

本研究以低成本的二甲基二甲氧基硅烷为主要原料，通过水解缩合反应制备合成了聚二甲基硅氧烷（PDMS），进而将其引入蓖麻油基水性聚氨酯（CWPU-SOP）中制备了具有防污性能的蓖麻油基水性聚氨酯(PDMS/CWPU-SOP)。结果表明，当PDMS引入量为8%时，与CWPU-SOP薄膜相比，PDMS/CWPU-SOP薄膜接触角提高了25?，达110?，PDMS/CWPU-SOP薄膜的吸水率下降了7%，为15%；PDMS提高了薄膜疏水性和耐水性。PDMS/CWPU-SOP薄膜在不同酸碱性的液滴在其表面可自由滚落且不留痕迹，具有一定的防污性能。     

聚氨酯改性环氧树脂的制备及红外光谱分析

制备了聚氨酯改性环氧树脂体系,并通过红外光谱分析,研究了异氰酸酯端基的聚氨酯预聚体、扩链剂、环氧树脂及其固化剂之间相互反应的规律。结果表明,聚氨酯、环氧树脂二者之间形成IPN结构过程中,环氧树脂与其固化剂之间发生固化反应;扩链剂1,4-丁二醇对PU预聚体进行扩链;同时TDE-85同PU预聚体之间还发生两相间的化学反应,这可有效地提高2种聚合物之间的相容性和稳定性,从而可以提高环氧树脂性能,达到改性目的。     

淀粉IPN型环保胶粘剂的合成

采用淀粉改性的聚醋酸乙烯酯(PVAc)乳液与聚氨酯(PU)预聚体交联制成了具有IPN(互穿网络聚合物)结构的胶粘剂。探讨了各原料的用量及反应温度等因素对该胶粘剂的制备及性能的影响。实验结果表明,制备该胶粘剂的适宜工艺条件为:氧化淀粉10.0g,水40.0g,聚乙烯醇(PVA)15.0g,PVAc25.0g,PU预聚体5.0g,乳化剂2mL,引发剂0.8g,扩链剂2mL,无机物填料5.0g,反应温度为65～85℃;由此制得的淀粉IPN型环保胶粘剂具有耐低温性好、耐水性佳、粘接强度高及无甲醛等优点,可用于层压板与纸塑、木塑复合材料的粘接。     

三元互穿聚合物网络弹性体的合成与性能

合成了以聚氨酯 (PU)为第一网络的三元IPN聚氨酯 /环氧树脂 /聚丙二醇二丙烯酸酯 (IPNPU/EP/PPGDA)互穿聚合物网络。分析了IPN的力学性能和萃取特性 ,结果表明 ,三元IPN的组成对力学性能和萃取特性有明显影响。该种弹性体具有优异的耐溶剂性 ,乙酸乙酯连续热萃取率仅为 5 %～ 11%。综合性能优异的三元IPN弹性体组成为m(PU) /m(EP) /m(PPGDA) =70 /2 5 /5 ,其机械性能为 :Ts=34 7MPa ,E =437% ,回弹性R =37%     

有机硅改性聚氨酯合成革涂饰剂的合成及性能

用聚醚多元醇(PPG)、聚二甲基硅氧烷(PDMS)、异佛尔酮二异氰酸酯(IPD I)、1,4-丁二醇(BDO)等为主要原料,合成了有机硅改性聚氨酯溶液。通过对合成条件的考察发现,反应温度为65℃,反应4 h,采用m(丁酮)∶m(二甲苯)=1∶1作溶剂,可得到黏度适中、性能良好的产品。考察了聚二甲基硅氧烷质量分数〔w(PDMS)〕对有机硅改性聚氨酯溶液及其成膜性能的影响。结果发现,随着w(PDMS)增加,溶液的黏度降低,成膜的热稳定性提高,当w(PDMS)=10%时成膜的水接触角达到最大值102.6°。     

Effect of crosslinking density on the physical properties of interpenetrating polymer networks of polyurethane and 2-hydroxyethyl methacrylate-teminated polyurethane

Interpenetrating polymer networks (IPNs) of 2-hydroxyethyl methacrylate-terminated polyurethane (HPU) and polyurethane (PU) with different crosslinking densities of the PU network were prepared by simultaneous solution polymerization. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) show that compatibility of component polymers in IPN formation depends on the crosslinking density of the PU network. Physical properties such as density and water absorption rely on the subtle balance between the degree of phase separation and the crosslinking density of the PU network. In spite of the occurrence of phase separation, the tensile moduli and tensile strength of the IPNs increase with the crosslinking density of the PU network. Morphological observation by scanning electron microscopy revealed different fracture surfaces between the compatible and incompatible IPNs. Surface characteristics of the IPNs, indicated as hydrogen bonding index and hard-to-soft segment ratio, are altered considerably by varying surface morphologies. Improved blood compatibility of IPN membranes is due to the variation of the hydrophilic and hydrophobic domain distribution.     

Kinetics of formation of polyurethane/polymethylmethacrylate grafted semi-interpenetrating polymer networks based on the functional prepolymers

Summary. The kinetics of formation of the polyurethane network by crosslinking the polyurethane prepolymer in polyurethane/polymethacrylate grafted semi-interpenetrating networks (semi-IPN) was monitored by Fourier transform infrared spectroscopy, and the kinetic parameters were thus determined. It was found that carboxylic groups in the hard segments of the Pu component substantially decrease the reaction rate and increase the activation energy. Tertiary amine groups in the PM component catalyse the crosslinking reaction. The PM component acts as a diluent in the mixture of PU and PM reducing the reaction rate and increasing the activation energy of the corsslinking reaction. At temperatures below the T_g of the PM component, the reaction of formation of IPN becomes diffusion controlled. Received: 2 May 1997/Revised: 11 July 1997/Accepted: 16 July 1997     

Structure and properties of semiinterpenetrating polymer networks based on polyurethane and nitrochitosan

Two semiinterpenetrating polymer networks (semi‐IPNs) based on trihydroxyl methylpropane–polyurethane (T‐PU) or castor oil–polyurethane (C‐PU) were prepared by curing the mixed solution of the polyurethane prepolymer and nitrochitosan (NCH). During the curing process, crosslinking and grafting reaction between the molecules of the PU prepolymer and NCH occurred, because of the high reactivity of remaining hydroxyl groups in the NCH with ? NCO groups of PU. The structure of the original semi‐IPN sheets and the sheets treated with acetone were studied by infrared, ¹³C‐NMR, scanning electron microscopy, and dynamic mechanical analysis, showing interpenetration of NCH molecules into the PU networks. When nitrochitosan content (C_NCH) was lower than 10 wt %, the semi‐IPN sheets T‐PU and C‐PU had higher density and tensile strength (σ_b) than the systems with C_NCH more than 20%. The trihydroxymethyl propane‐based PU reacted more readily with nitrochitosan to form the semi‐IPNs than castor oil‐based PU. The semi‐IPN coatings T‐PU and C‐PU were used to coat cellophane, resulting in intimate interfacial bonding. The mechanical strength and water resistivity of the cellophane coated with T‐PU coating were improved remarkably. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3109–3117, 2001     

互穿聚合物网络技术在聚氨酯中的应用

综述了互穿聚合物网络(IPN)技术在聚氨酯材料中的应用研究进展。简述了聚氨酯IPN的制备,具体叙述环氧树脂、聚丙烯酸酯、聚硅氧烷、乙烯基酯树脂等聚合物与聚氨酯互穿网络改性的效果,并在此基础上展望了聚氨酯互穿网络聚合物的发展趋势。     

Interpenetrating polymer networks of polyurethane and furfuryl alcohol,IIa. Processability and properties of pultruded fiber-reinforced composites

A feasibility study of pultrusion of fiber-reinforced polyurethane/furfuryl alcohol (PU/FA) interpenetrating polymer/network IPN composites has been made. From the viscosity study, it was found that the pot life of the PU/FA IPN prepolymers increased with PU content and showed high reactivity at elevated temperature. It was confirmed from the morphological study that the wetting of fibers by the PU/FA IPN resins was improved with PU content. The appearance of the tensile failure surfaces of the pultruded glass fiber-reinforced PU/FA IPN composites showed “hackle patterns” for PU contents below 15 phr. The mechanical property study shows that the tensile strength of pultruded PU/FA IPN composites is the highest when the PU content is 5 phr. However, the flexural strength, flexural modulus and HDT decreased with PU content. The mechanical properties of various fiber-reinforced (glass, carbon, and Kevlar 49 aramid fiber) pultruded PU/FA IPN composites increased with fiber volume content.     

用FTIR研究聚氨酯／不饱和聚酯IPN体系的反应动力学

利用傅里叶变换红外光谱研究聚氨酯不饱和聚酯互穿聚合物网络体系的反应动力学，求出了ＰＵ的反应速度常数ｋ。实验结果表明，ＰＵ在半－ＩＰＮ体系中的反应为二级反应，ＩＰＮ体系中ＰＵ组分与ＵＰ组分的反应相互影响：ＵＰ组分使ＰＵ组分的前期反应速度变慢，后期反应速度相对增加；ＰＵ组分使ＵＰ组分聚合的诱导期明显缩短。ＰＵ和ＵＰ的配比对反应转化率的影响是反应前期ＰＵ组分含量越高，ＰＵ组分反应转化率也越高；反应后期，     

Synthesis of biodegradable PU/PEGDA IPNs having micro-separated morphology for enhanced blood compatibility

Summary New biodegradable hydrophobic polyurethane (PU)/hydrophilic poly (ethylene glycol) diacrylate (PEGDA) IPN was simultaneously synthesized with changing the molecular weight of PEGDA to investigate the effect of crosslinking density on the degree of phase separation. PU was modified using biodegradable poly(-caprolactone)diol and the hydroxy group of PEG was substituted to crosslinkable acrylate group having double bond, which induce photo-polymerization. The sturucture of PEGDA was confirmed by NMR. Because the reaction rate of PEGDA was faster than that of PU, the continuous matrix of the micro-separated PU/PEGDA IPNs having amphiphilic character was made of hydrophilic PEGDA-rich phase. All IPNs have sea-island morphology resulting from the suppressed phase separation. The effect of the degree of phase separation on blood compatibility was investigated.     

聚氨酯／呋喃树脂互穿聚合物网络性能的研究

用糠醇型呋喃树脂或ＨＦ９２００Ａ环氧型呋喃树脂与聚环氧丙烷醚型聚氨酯制备了互穿聚合物网络（ＩＰＮ）。通过红外光谱和扫描电子显微镜分析了聚氨酯（ＰＵ）／呋喃树脂（ＦＡ）ＩＰＮ网络形成的动力学和微相分离行为，并考察了不同配比下ＩＰＮ的力学性能。实验结果表明，ＰＵ／ＦＡ达到某一比值时，产生互穿聚合物网络的协同效应，可改善聚氨酯的刚性，提高呋喃树脂的抗冲击等性能     

Synthesis,thermal properties,and morphology of blocked polyurethane/epoxy full‐interpenetrating polymer network

Blocked polyurethane (PU)/epoxy full‐interpenetrating polymer network (full‐IPN) were synthesized from blocked NCO‐terminated PU prepolymer, with 4,4‐methylene diamine as a chain extender and epoxy prepolymer, with 4,4‐methylene diamine as a curing agent, using simultaneous polymerization (SIN) method. From FTIR spectra analysis it was found that the major reactions in the blocked PU/epoxy IPN system are the self‐polymerization of block PU/chain extender and the self‐polymerization of epoxy/curing agent. Meanwhile, from reaction mechanisms the copolymerization of IPN may have occurred at the same time. The weight loss by thermogravimetric analysis decreased with increasing epoxy and filler content. It was confirmed from scanning electron micrography (SEM) that when the blocked PU content increased, the microstructure of IPN became rougher. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 323–328, 2006