超低单醇含量聚醚基软质聚氨酯泡沫的研究

以双金属络合氰化物(DMC)为催化剂,首先制备出超低单醇含量、高分子量的聚氧化丙烯醚多元醇。用这种聚醚多元醇采用全水发泡体系合成软质聚氨酯泡沫塑料,通过物理机械性能的检测表明,用DMC聚醚多元醇比常规的PPG聚醚多元醇制备的软质聚氨酯泡沫塑料具有更优越的理化性能和开发应用价值。     

网络间含离子键的聚氨酯/接枝乙烯基酯树脂互穿聚合物网络 研究

分别以双酚-A型环氧树脂E-51和聚醚型环氧树脂E-46为原料合成了两种二乙胺-环氧树脂和加成多元醇(分别命名为AE-51,AE-46),将其和甲基丙烯酸一起用于合成聚氨酯/接枝乙烯基酯树脂(PU/接枝VER)互穿聚合物网络(IPN),使之在两个网络间形成离子键。实验结果表明,这类新型的IPN材料中两个网络间的互穿程度与相容性进一步提高,从而导致刚性的接枝VER对弹性的PU网络有更好的增强效果。DSC和FTIR的测定结果表明,在含AE-51的IPN中,由于离子键的作用使PU网络硬段的有序结构遭到很大程度的破坏,与AE-51和PU网络中的硬段以及VER网络有较好的相容性有关,因此这类IPN材料具有较好的力学性能。     

具有超支化结构的聚醚型脂肪族聚氨酯弹性体的合成与表征及力学性能研究

用聚四氢呋喃醚二醇、端羟基超支化聚酯(HB-20)、异佛尔酮二异氰酸酯和1,4-丁二醇,合成了含有超支化结构的聚醚型脂肪族聚氨酯(PU)弹性体.通过Flory-Rehner公式计算了体系的交联密度;用FT-IR、WAXD和DSC表征了超支化PU的氢键化程度和形态.实验结果表明,在PU弹性体中引入少量的HB-20,能提高氨基甲酸酯羰基的氢键化程度和软硬段间的微相分离程度,从而显著提高材料的拉伸强度.由于氢键化程度和交联密度双重效应的影响,含6 wt%HB-20的聚醚型PU与不含HB-20的PU相比拉伸强度提高了2倍多,达到37.9 MPa,断裂伸长率仍高达414%.     

聚氨酯与接枝乙烯基酯树脂互穿网络研究: 自由基共聚 单体的影响

通过分子设计技术合成了两种侧链种类和长度可能控制的接枝乙烯基酯树脂(VER),并用它们与聚氨酯(PU)形成了同步互穿网络(SIN)。通过DSC,SEM,TEM,FTIR等考察了接枝VER的共聚单体对VERSIN的形态结构与力学性能的影响。研究结果表明,用甲基丙烯酸甲酯(MMA)为共聚单体的接枝VER网络中的MMA链段与PU网络中的硬段有较好的相容性,导致这类PU/接枝VERSIN中两个网络间的相容性和互穿程度好于由苯乙烯为共聚单体时合成4SIN。因此,在这两类共聚单体合成的SIN中,由MMA形成的接枝VER网络增强PU网络的效果更为显著。     

丝素蛋白-聚氨酯水凝胶的制备和性能

以异佛尔酮二异氰酸酯（IPDI）、聚乙二醇（PEG）、聚氧化丙烯二醇（PPG）等为主要原料,合成了一系列—NCO封端的水性聚氨酯（PU）预聚体,与自制的丝素蛋白（SF）水溶液混合进行交联反应,制备出丝素蛋白-聚氨酯（SF-PU）水凝胶。研究了SF-PU水凝胶的合成工艺,对SF-PU水凝胶进行了红外和电镜表征及性能测试,...     

微相分离及链结构对聚酯-聚醚嵌段共聚物分子运动的影响

本文首先研究了成型方法和热处理对聚对苯二甲酸乙二酯与聚氧四亚甲基嵌段共聚物动态力学温度谱的影响,结合应力-应变曲线讨论了微相分离与力学性能的关系。其次,比较了三种不同链结构的聚酯-聚醚嵌段共聚物在不同温控程序下的动态力学温度谱,讨论了链结构对软链段结晶的影响。最后观察了聚氨酯-聚醚嵌段共聚物双重玻璃化转变现象并作了解释。     

聚酚酞醚砜-聚硅氧烷-聚醚氨酯多嵌段聚合物

<正> 合成了端异氰酸酯基聚硅氧烷-聚醚氨酯嵌段预聚物和端羟基酚酞醚砜齐聚物,探索了上述预聚物与齐聚物间的活泼氢转移加成反应,对所得的多嵌段聚合物做了初步的结构形态表征。 试验用单体:酚酞、4,4′-二氯二苯砜、TDL_(2,4)、MDI、低分子量聚氧化丙烯二醇N-     

聚醚聚氨酯-聚醚聚酰亚胺合金相结构的研究

通过不同分子量的对－氨基苯甲酸酯封端的聚（四次亚甲基）醚和均苯甲甲酸二酐反应,合成了聚醚聚酰胺酸;然后以不同重量比将聚醚聚氨酯和聚醚聚酰胺酸溶液混合反应亚胺化,制备了一系列不同硬段含量的聚醚聚氨酯－聚醚聚酰亚胺合金。用傅立叶变换红外光谱、动态力学分析、示差扫描量热、广角Ｘ－衍射、应力应变试验等分析测试方法对合金进行了研究,结果表明聚醚聚氨酯－聚醚聚酰亚胺合金具有很好的相分离结构,是一类新型耐高温、有韧性的热塑性弹性体。聚醚分子量相同的聚氨酯和聚酰亚胺形成的合金软段相容,合金具有两相结构;聚醚分子量不同的聚氨酯和聚酰亚胺形成的合金软段存在相分离,合金具有三相结构,表现在材料外观上分别为透明不透明的韧性膜,少量聚酰亚胺的掺入,能大大增加材料的耐热性能,而合金的材料力学性能没有明显变化。     

用正电子湮没谱研究聚酯型聚氨酯的微观结构和自由体积特性

用正电子湮没谱研究了两类分别由聚己二酸丁二醇酯多元醇和聚ε 己内酯多元醇合成的线型聚酯型聚氨酯 (PBU和PCU)在 140～ 36 0K温度范围内的结构转变和自由体积特性 .研究结果表明 ,两类聚氨酯(PU)在 140～ 36 0K温度范围内 ,都存在三个转变点 ,其中较低温度的转变 (约 2 0 0K)对应于PU中软段的玻璃化转变温度 (Tg) ,2 75K处的转变可能与样品吸附少量水分有关 ,较高温度的转变 (约 310K) ,对于PBU而言对应于软段结晶的熔点 ,而对于PCU则与在无序的硬段中混入一定量的软段后形成的相容区的Tg 有关 .当温度低于PU软段的Tg 时 ,两类PU的自由体积尺寸和浓度都随温度升高而增大 .当温度高于软段的Tg 但低于2 75K时 ,自由体积尺寸较快地增加 ,而自由体积浓度保持不变 .温度高于 2 75K并低于软段的熔点或硬段 软段相容区的Tg 时 ,自由体积尺寸增加速度最快 ,自由体积浓度却保持同样的数值 .当温度进一步升高时 ,自由体积尺寸和浓度都随温度增大而增加 .最后研究了这两类PU的自由体积分布与温度的关系 .所有这些实验现象均与大分子链的运动有关 ,并与通过DSC和WAXD表征的材料的形态一致     

聚醚多元醇对环氧树脂的增韧改性

通过力学性能、热性能以及扫描电镜等方法研究了聚醚多元醇对环氧树脂-酸酐体系的增韧效果。结果表明:聚醚多元醇在环氧固化过程中分相析出,呈现出较好的增韧效果;在环氧-酸酐体系中,大分子量聚醚多元醇的增韧效果不如小分子量的;而由环氧乙烷封端的聚醚多元醇,由于含有与环氧树脂相容的聚环氧乙烷(PEO)链段,分散相与环氧母体间能够形成良好的界面作用,也体现出良好的增韧效果。     

Graft interpenetrating polymer networks of polyurethane and epoxy. I. mechanical behavior

Polyurethanes (PU) based on poly(butylene adipate) [PU(PBA)] and poly(oxypropylene) [PU(PPG)] polyols have bean introduced into the diglycidyl ether of bisphenol A (epoxy) to form interpenetrating polymer networks (IPNs) with a PU-grafted epoxy structure (graft-IPNs). The tensile strength in both PU(PPG)/epoxy and PU(PBA)/epoxy systems increases with increasing PU content. Maximum values emerge at PU/epoxy ratios between 19/81 and 27/73. This is explained as a result of the presence of the graft structure, which leads to more intimate interpenetration between the PU and epoxy in the graft-IPNs. Dynamic mechanical analysis (DMA) indicates that the PU introduced can be incorporated in either the α or β transition domain of the epoxy. The tensile strength of the resulting graft-IPNs shows a significant improvement as the PU is incorporated in the α transition domain of the epoxy. It is also noted that suitable amounts of PU incorporated in both the α and β transition domains of epoxy can increase the tensile strength of the IPNs, while excessive amounts of PU introduced into both α or β transition domains tend to decrease the tensile strength of the graft-IPNs.     

Interpenetrating polymer networks of polyurethane and graft vinyl ester resin–polyurethane formed with diphenylmethane diisocyanate

For enhancing the compatibility and/or the interpenetration of the simultaneous interpenetrating networks (SINs) composed of polyurethane (PU) formed with uretonimine modified 4,4′‐diphenylmethane diisocyanate and vinyl ester resin (VER), a series of graft VERs consisting of different lengths of side chains were synthesized and characterized. It was found that there exists some limited short‐range order due to the strong hydrogen bonding in the graft VER network composed of butanol side chains (BO‐g‐VER). The graft VER network composed of poly(oxypropylene) (PPO) side chains (M_n: 200, 200‐g‐VER) showed compatible system, while the VER network consisting of longer PPO grafts (M_n: 390, 390‐g‐VER) exhibited microphase separated morphology. Based upon the DSC and FTIR measurements as well as the SEM and TEM observation, the lengths of side chains existing in graft VER network have great effect on the morphologies of PU/graft VER SINs. For PU/BO‐g‐VER SINs, there has been some interpenetration between the two networks because of the miscibility between the BO‐g‐VER network and the hard segments existing in the PU network. For PU/200‐g‐VER SINs, the good compatibility and/or the interpenetration between the two phases was observed, since the long‐range ordered structure of hard segments in PU phase was greatly suppressed, resulting from the excellent miscibility between the urethane groups as well as the PPO side chains existing in the 200‐g‐VER network and those in the PU network, respectively. Thus, the strong reinforcement effect of these two graft networks on the PU network and the excellent mechanical properties of the SIN systems were observed. However, the PU/390‐g‐VER SINs showed the complicated morphologies because of existing microphase‐ separated morphology of 390‐g‐VER network in itself. In this case, the enhancement effect of such a graft VER network on the PU network is limited. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 136–144, 2000     

Structure development during sol-gel process in organic-silica networks

Two types of the organic-silica hybrid networks were prepared and their formation and structure were studied in dependence on reaction conditions. The silica phase was formed by the sol-gel process from tetraethoxysilane (TEOS) or alkoxysilane endcapped prepolymers. The organic phase was composed of linear poly(oxypropylene) chain or the epoxide network arising by curing the diglycidyl ether of Bisphenol A (DGEBA) with poly(oxypropylene)diamine. Fast development of the structure during polymerization was followed by the in-situ small-angle X-ray scattering measurement. One- and two-stage polymerization procedures result in formation of heterogeneous but optically transparent nanocomposites with different structures.     

Swelling equilibrium and sorption kinetics of urethane-modified bismaleimides elastomer

The swelling equilibrium and diffusion kinetics in various solvents of the maleimide-terminated polyurethanes (UBMIs) and of the triol and tetraol-crosslinked polyurethanes (PU) were studied. The polymer volume fraction of the UBMIs at swelling equilibrium is much higher than that of the tetraol-crosslinked PU networks for the same type of polyol used in the PU. It was explained by the high functionality of the UBMIs produced in the network structure. Furthermore, the molecular weight between crosslinks (M_c) has been calculated from the swelling model and the results exhibit good agreement with the proposed network structure. The early time sorption kinetic data were obtained to investigate the diffusion mechanism of the solvent in the networks. The solubility, diffusion coefficients, and permeability of the solvent in UBMI networks were found to be lower than in the multiol-crosslinked PU networks. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1747–1755, 1997     

Heterogeneity of glass transition dynamics in polyurethane‐poly(2‐hydroxyethyl methacrylate) semi‐interpenetrating polymer networks

The peculiarities of segmental dynamics over the temperature range of ?140 to 180 °C were studied in polyurethane‐poly(2‐hydroxyethyl methacrylate) semi‐interpenetrating polymer networks (PU‐PHEMA semi‐IPNs) with two‐phase, nanoheterogeneous structure. The networks were synthesized by the sequential method when the PU network was obtained from poly(oxypropylene glycol) (PPG) and adduct of trimethylolpropane (TMP) and toluylene diisocyanate (TDI), and then swollen with 2‐hydroxyethyl methacrylate monomer with its subsequent photopolymerization. PHEMA content in the semi‐IPNs varied from 10 to 57 wt %. Laser‐interferometric creep rate spectroscopy (CRS), supplemented with differential scanning calorimetry (DSC), was used for discrete dynamic analysis of these IPNs. The effects of anomalous, large broadening of the PHEMA glass transition to higher temperatures in comparison with that of neat PHEMA, despite much lower T_g of the PU constituent, and the pronounced heterogeneity of glass transition dynamics were found in these networks. Up to 3 or 4 overlapping creep rate peaks, characterizing different segmental dynamics modes, have been registered within both PU and PHEMA glass transitions in these semi‐IPNs. On the whole, the united semi‐IPN glass transition ranged virtually from ?60 to 160 °C. As proved by IR spectra, some hybridization of the semi‐IPN constituents took place, and therefore the effects observed could be properly interpreted in the framework of the notion of “constrained dynamics.” The peculiar segmental dynamics in the semi‐IPNs studied may help in developing advanced biomedical, damping, and membrane materials based thereon. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 963–975, 2007     

反应注射成型聚氨酯互穿聚合物网络研究——刚性网络对于体系形态及性能的影响

用微型反应注射成型机制备了以聚氨酯(PU)为弹性相的两类同步互穿聚合物网络(SIN),其刚性相分别采用保留仲羟基的乙烯基酯树脂(VERH)以及封闭仲羟基的乙烯基酯树脂(VERA)。用傅里叶变换红外光谱在线跟踪了这类互穿网络的生成过程,发现刚性网络抑制了PU网络中硬段有序结构的形成,两个网络间有一定程度的互穿,而两个网络间的化学键作用进一步削弱氢键强度。自旋—自旋弛豫时间的测定进一步表明网络间存在一定的互穿以及刚性相对于PU硬段结晶的抑制作用。材料的力学性能与其SIN的形态有关。VERA网络对PU表现出明显的增强作用,而由VERH网络形成的SIN则由于体系相分离进程受到严重阻碍而使材料性能恶化。     

用可再生原料合成聚氨酯脲水分散液——成膜后的结构与性能研究

以不同组成的蓖麻油和二官能度聚醚多元醇 (GE 2 10 )等原料合成了聚氨酯脲 (PUU)水分散液 ,研究了蓖麻油 GE 2 10的组成对PUU膜结构与性能的影响 .结果表明 ,由GE 2 10合成的PUU虽软硬段间存在一定的相容性 ,但其中脲羰基的氢键化程度高 ,硬段形成较好的有序结构 ,导致PUU膜具有较高的拉伸强度及断裂伸长率 ,但弹性模量和硬度下降 .在蓖麻油合成的PUU中脲羰基的氢键化程度及硬段有序结构均受到化学交联结构的抑制 ,故PUU膜的拉伸强度和断裂伸长率降低 ,但弹性模量及硬度较高 .由蓖麻油与GE 2 10在一定的组成范围内合成的PUU膜 ,具有优良的综合平衡的力学性能 ,后者与材料的结构形态相符     

甲苯二异氰酸酯形成的聚氨酯脲与接枝乙烯基酯树脂互穿网络研究

本文首先通过分子设计技术合成了一系列侧链长度可以控制的接枝乙烯基酯树脂 (接枝VER :BO g VER ,2 0 0 g VER ,390 g VER) ,并用它们与甲苯二异氰酸酯合成的聚氨酯脲 (PUU)形成同步互穿网络(SIN) .通过DSC、SEM等考察了接枝VER的结构对PUU/接枝VERSIN的形态与力学性能的影响 .在PUU/BO g VERSIN中 ,BO g VER网络主要与PUU网络中的硬段相容和互穿 ;对于PUU/ 2 0 0 g VERSIN而言 ,2 0 0 g VER网络与PUU网络中的软段和硬段均有一定的相容性 .由于这两种SIN中两个网络间均有一定的相容性和互穿 ,故这类接枝网络能显著地增强PUU网络 ,使材料的力学性能有较大幅度的提高 .390 g VER网络本身存在的微相分离结构 ,使PUU/ 390 g VERSIN两个网络也存在显著的相分离形态 ,导致390 g VER网络对PUU网络的增强效果并不明显 .