聚醚型聚氨酯增强增韧环氧树脂的研究

用聚丙二醇(PPG400,PPG1000)与异佛尔酮二异氰酸酯(IPDI)反应制备了聚氨酯(PU)预聚体,然后通过与环氧树脂(EP)的加成反应和环氧树脂的固化反应将聚氨酯引入环氧固化物网络,并研究了两种聚醚型聚氨酯对环氧树脂的改性效果。结果发现,聚氨酯的引入不但起到了增韧的作用,而且使体系的强度有了很大的提高。随聚氨酯用量增大,PU/EP材料拉伸强度、弯曲强度、冲击强度均先增大后减小,过多的聚氨酯用量导致其不能接人环氧固化物网络;分子链较短的PPG400型聚氨酯的改性效果优于PPG1000,PU与EP的质量之比的最佳值为15%～20%;1,4-丁二醇/三羟甲基丙烷的引入能够使体系中聚氨酯分子链增长并交联成网状,但并不能进一步提高PU/EP材料的强度和韧性。     

聚氨酯/乙烯基酯树脂互穿聚合物网络泡沫性能研究

研究了两种不同固化体系对乙烯基酯树脂(VER)的固化和对聚氨酯(PU)网络的匹配,以及单体结构和配比对PU/VERIPN硬质泡沫塑料力学性能和阻尼性能的影响规律。确定了过氧化二苯甲酰和N,N-二甲基苯胺合用的固化剂体系。实验表明,增加IPN中PU网络的高羟值聚醚(N303)的添加量,PU/VERIPN泡沫材料的压缩强度和压缩模量增大,冲击强度下降。S组的泡沫塑料的VER和PU具有较好的相容性,其Tanδ曲线出现一个很宽的阻尼平台,表现出较好的低温阻尼性能。     

环氧树脂／聚氨酯梯度聚合物的弯曲性能研究

考察了不同层数的环氧树脂/聚氨酯(EP/PU)梯度聚合物弯曲性能,采用有限元法分析了材料在弯曲状态下的应力分布,从理论上解释了EP/PU梯度材料弯曲性能的试验结果,并与相同组成的均质材料进行了比较.研究发现:EP/PU梯度材料的弯曲强度和模量随梯度层数的增加而增加,当梯度层数超过5层以后,EP/PU梯度材料的弯曲强度高于相同组成的均质材料.有限元分析结果表明:在EP/PU梯度材料中,应力的分布与各层材料承受的强度相匹配,即应力大的部位材料的强度也越大.梯度层越多,各层之间强度变化越小,应力变化越为缓和,且应力分布与材料强度之间匹配越好,在受外力时,材料断裂强度越高.梯度材料中应力分布方式的理论计算结果很好的解释了实测的各种梯度材料强度变化规律.     

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。     

聚氨酯/环氧树脂互穿网络半硬泡沫的压缩力学性能

采用同步法制备了聚氨酯/环氧树脂互穿聚合物网络(IPN)半硬泡沫。研究了IPN泡沫密度及环氧树脂用量对压缩力学性能的影响。研究表明,在所研究的泡沫密度范围内,压缩模量、屈服强度均与泡沫材料密度成指数关系,并且这种指数关系可以根据数学模型用泡沫材料的相对密度表示,且理论曲线与实验曲线吻合较好。因此,利用该模型可以对泡沫的压缩性能进行预测。IPN泡沫的压缩模量和屈服强度与环氧树脂用量成指数式增长关系,当环氧树脂的质量分数超过20%时压缩模量和屈服强度显著提高。     

含溴环氧树脂对聚氨酯硬泡性能的影响

采用聚醚多元醇、多亚甲基多苯基多异氰酸酯(PAPI)、泡沫稳定剂、催化剂、高效阻燃剂、发泡剂、含溴环氧树脂等原料通过一步法制备了聚氨酯硬质泡沫材料,研究了不同含溴环氧树脂添加比例的聚氨酯硬质泡沫材料的压缩强度和阻燃指数。结果表明,随着含溴环氧树脂添加量的增加,压缩强度出现先增加后减少的趋势。在含溴环氧树脂添加量占白料总质量10%时,压缩性能最佳;随着含溴环氧树脂添加量的增加,聚氨酯硬泡的极限氧指数呈上升趋势;高效阻燃剂用量可以使改性聚氨酯硬泡极限氧指数得到显著增加,达到30%以上。     

PU/EP型水声吸声材料动态模量和声学参数的实验研究

采用聚氨酯(PU)和环氧树脂(EP)及云母填料合成了PU/EP二元IPN水声吸声材料,对该材料的动态模量和声速进行了测量,研究了EP含量和云母填料及含量对材料动态模量及声速的影响,并对材料的吸声性能进行了分析。结果表明,材料弹性模量越大,材料中声波传播速度就越大;随着填料含量的增加,声速的下降幅度增大。并用直观的物理量表征了抽象的声学量,为指导水声材料的设计提供了基础。     

助剂对全水发泡阻燃聚氨酯硬泡性能的影响

采用聚醚多元醇、多异氰酸酯、泡沫稳定剂、液态阻燃剂、催化剂和水制备了全水发泡阻燃硬质聚氨酯泡沫塑料,研究了水用量、催化剂、泡沫稳定剂及阻燃剂对聚氨酯硬泡性能的影响。结果表明,水用量影响聚氨酯硬泡的泡沫密度、压缩强度、尺寸稳定性、吸水率等性能;不同催化剂复配影响聚氨酯硬泡的泡孔结构;泡沫稳定剂影响泡孔均匀性和聚氨酯硬泡的导热性能;磷酸三乙酯(TEP)对硬泡阻燃性能的影响优于磷酸三氯丙酯(TCPP)和阻燃聚醚多元醇(F-7190)。随TEP用量的增加,聚氨酯硬泡的氧指数增大,压缩强度降低;随F-7190用量增加,聚氨酯硬泡的氧指数略有增大,压缩强度先增大后变小。     

长玻纤增强反应注射成型PU泡沫塑料的力学性能

利用高压喷灌机开展了长玻纤增强硬质聚氨酯泡沫塑料(RPUF)的成型技术研究。结果表明:RPUF的弯曲模量随着玻纤用量的增加而增大;密度为0.75 g/cm3的RPUF的弯曲强度随玻纤用量的增加而减小,密度为0.95g/cm3的RPUF的弯曲强度随玻纤用量的增加而增大,当玻纤质量分数大于40%时,弯曲强度开始下降;在载荷垂直于玻纤的分布方向,RPUF的压缩模量随着玻纤用量的增加先增大后减小,在载荷平行于玻纤分布方向,压缩模量随着玻纤用量的增加而增大;RPUF的压缩强度随着玻纤用量的增加而减小;RPUF的压缩强度和压缩模量在载荷平行于玻纤分布方向明显高于载荷垂直于玻纤分布方向;随着玻纤用量和长度的增加,RPUF的冲击强度均明显提高。     

废旧聚氨酯硬质泡沫塑料的降解回收及再利用

采用双组分醇解剂乙二醇（EG）和丙二醇（PG）对废旧聚氨酯（PU）硬质泡沫塑料进行降解,获得了降解产物低聚物多元醇,并将其与木质素为原料制备出再生聚氨酯（r?PU）硬质泡沫塑料复合材料。利用导热系数测定仪、扫描电子显微镜、热重分析仪、傅里叶变换红外光谱仪等对废旧PU的降解效果和r?PU硬质泡沫复合材料的压缩强度、吸水率、导热系数、微观形貌及热稳定性等进行了分析和表征。结果表明,双组分醇解剂EG和PG质量比（m_EG：m_PG）为2：3时,废旧PU的降解效果最佳;当木质素添加量为6 %（质量分数,下同）时制备r?PU硬质泡沫复合材料的泡沫孔壁较厚且比较均匀,骨架几何构型完整,其压缩强度为185.3 kPa、导热系数为0.021 5 W/（m·K）,均能够达到国家标准要求。     

Interpenetrating polymer network and nanocomposite IPN of polyurethane/epoxy: a review on fundamentals and advancements

This article presents state-of-the-art review on interpenetrating polymer network (IPN) formation by polyurethane/epoxy (PU/EP). PU is thermoplastic polymer with fine mechanical strength, chemical resistance, processability, and thermal stability. EP resins also possess unique chemical and physical properties, though it is rigid and brittle. Amalgamation of two polymers have resulted in improved mechanical, thermal, damping, and glass transition behavior. PU/EP IPN and nanocomposite containing carbon nanotube, graphene oxide, nanodiamond, nanoclay, and various other nanoparticles have been discussed. Commercial implication and future prospects of PU/EP-crosslinked network and nanocomposite IPN are foreseen in high-performance engineering materials, automotive and aerospace, and biomedical devices.     

Rigid interpenetrating polymer network foams prepared from a rosin-based polyurethane and an epoxy resin

A series of rigid interpenetrating polymer network (IPN) foams, based on a rosin-based polyurethane and an epoxy resin, were prepared by a simultaneous polymerization technique. The changes in the chemical structure, dynamic mechanical properties, and morphology of the rigid IPN foams were investigated by Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical thermal analysis, and scanning electron microscopy. The FTIR analysis showed clearly that the cure rate of the rosin-based rigid polyurethane foam and the epoxy resin were different and, as a result, these two networks formed sequentially in the final rigid IPN foams. All of the rigid IPN foams exhibited a single, broad glass transition that shifted to lower temperature as the epoxy resin content increased. The experimental composition dependence of T_g's of the rigid IPN foams showed slight positive deviation from the Fox equation for homogeneous polymer systems. No phase separation was observed from the scanning electron microscopy investigation. It could be concluded that these two component networks were compatible in the final rigid IPN foams. This compatibility could be attributed to a graft structure in the polyurethane and the epoxy resin networks arising from the reaction of the hydroxyl groups of the epoxy resin with the isocyanate groups of MDI, and from the reaction of the hydroxyl groups of the polyols with the epoxide groups of the epoxy resin, as suggested by FTIR analysis. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 271–281, 1998     

Reinforcement of polyurethane/epoxy interpenetrating network nanocomposites with an organically modified palygorskite

An organophilic palygorskite (o‐PGS) prepared by the treatment of natural palygorskite with hexadecyl trimethyl ammonium bromide was incorporated into interpenetrating polymer networks (IPNs) of polyurethane (PU) and epoxy resin (EP), and a series of PU/EP/clay nanocomposites were obtained by a sequential polymeric technique and compression‐molding method. X‐ray diffraction and scanning electron microscopy analysis showed that adding nanosize o‐PGS could promote the compatibility and phase structure of PU/EP IPN matrices. Tensile testing and thermal analysis proved that the mechanical and thermal properties of the PU/EP IPN nanocomposites were superior to those of the pure PU/EP IPN. This was attributed to the special fibrillar structure of palygorskite and the synergistic effect between o‐PGS and the IPN matrices. In addition, the swelling behavior studies indicated that the crosslink density of PU/EP IPN gradually increased with increasing o‐PGS content. The reason may be that o‐PGS made the chains more rigid and dense. As for the flame retardancy, the PU/EP nanocomposites had a higher limiting oxygen index than the pure PU. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Tribological mechanism improving the wear resistance of polyurethane/epoxy interpenetrating polymer network via nanodiamond hybridization

The excellent synergistic effect of physical/mechanical properties of polyurethane/epoxy (PU/EP) interpenetrating polymer network (IPN) and the validity of nanofilling have one potential to improve the wear resistance of polymeric materials. With the aim of practical application, PU/EP IPN nanocomposites are prepared with nanodiamond (ND) as a reinforcing additive. Results showed the uniform thermal stability and the excellent compatibility between PU and EP in ND‐hybridized PU/EP IPN. Simultaneously, ND particles work as crosslinked points improving the physical/mechanical properties of ND‐hybridized PU/EP IPN, especially the wear resistance. The measurement of tribological property and the scanning electron microscope indicated that the wear resistance is able to be improved a lot by the formation of IPN and by the addition of ND. Consequently, the tribological mechanism of PU/EP IPN nanocomposites comes into being. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40244.     

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     

可再生聚酯多元醇的合成及其在聚氨酯材料中的应用

采用油酸为主要原料合成了羟值为236mgKOH／g、酸值为2．8mgKOH／g的可再生聚酯多元醇,并以此聚酯多元醇为原料制备了聚氨酯硬质泡沫。研究了该聚酯多元醇用量对泡沫发泡和力学性能的影响。结果表明,随着聚酯多元醇加入量的增加,形成聚氨酯硬质泡沫的反应速度增加;与纯聚醚多元醇制备的聚氨酯硬质泡沫相比,加入20％～30％的该聚酯多元醇制备的聚氨酯泡沫的尺寸稳定性和压缩强度增加。     

Synthesis and characterization of nanocomposites of silicon dioxide and polyurethane and epoxy resin interpenetrating network

Nanocomposites with varying concentrations of nanosized silicon dioxide particles were prepared by adding nanosilica to interpenetrating polymer networks (IPN)s of polyurethane and epoxy resin (PU/EP). The PU/EP IPNs and nanocomposites were studied by dynamic mechanical analysis, scanning electronic microscopy, wide‐angle X‐ray diffraction and small‐angle X‐ray scattering. The result showed that adding nanosize silicon dioxide can improve the properties of compatibility, damping and phase structure of IPN matrices. Copyright © 2003 Society of Chemical Industry     

Mechanical properties of BaTiO3 open-porosity foams

Barium titanate (BaTiO₃) foams synthesized via direct foaming method using silicon-free, rigid polyurethane systems (PU), commercially purchased and lab developed, are being engineered for piezocomposites in sonar applications. The mechanical properties of these foams were measured using confined compression testing to evaluate the suitability of these foams for the intended application. Compressive modulus and collapse strain determined from the experimental data increased with increasing density. Additionally, the foams fabricated using the lab developed PU (LPU) showed a higher mechanical strength due to a higher average density than the foams developed using commercial PU (CPU) system. The data was then fit with a phenomenological model to verify the values of the compressive properties extracted from the experimental data and also to extract additional properties such as tensile strength. Based on these findings, it is proposed that these foams can be successfully incorporated into piezocomposites by infiltrating the foams with polymer.