单组分聚氨酯清漆的制备与性能研究

不同的聚碳酸酯二元醇、聚四亚甲基醚二醇(PTMG)与二苯甲烷二异氰酸酯(MDI)、小分子二元醇反应,制得聚醚、聚碳酸酯型聚氨酯清漆。通过红外光谱分析结合其机械力学性能、耐水性等的测试结果,探讨聚碳酸酯型聚氨酯清漆的结构对形态和性能的影响。结果表明：随着硬段含量的增加,树脂涂膜的微相分离程度增加,机械性能提高;组分摩尔比例相同时,软段分子量的降低有利于提高树脂的软硬段相容性,增加树脂涂膜的物理机械性能;组分摩尔比例相同时聚酯型聚氨酯树脂的微相分离程度低于聚醚型聚氨酯树脂;MDI基溶剂型聚氨酯树脂的物理机械性能较好。     

聚醚型聚氨酯脲的氢键研究

简要评述了近年来有关聚醚型聚氨酯脲氢键研究进展，红外光谱中聚醚型氨酯脲的羰基谱带，特别是脲羰基谱带受化学组成，硬段的结构和制样条件等的影响，而呈现复杂的多重谱带特征，对于这些谱带目前已经作了较系统的归属。     

聚氧乙烯功能基复合修饰聚氨酯合成及其血液相容性研究 (Ⅱ)──聚氨酯-接枝-聚氧乙烯氨基酸衍生物

采用以磺酸基为末端基的聚氧乙烯(PEO)接枝聚醚氨酯和氨基酸反应,将赖氨酸(Lys)和酪氨酸(Tyr)通过PEO为"间隔臂"固定在聚醚氨酯上,制备了氨基酸和PEO复合修饰的聚醚氨酯PEU-g-PEO-SO₂Lys和PEU-g-PEO-SO₂Tyr.通过血小板粘附试验对材料的体外抗凝血性进行了初步评价.研究结果表明,采用具有选择性吸附纤溶酶原功能的赖氨酸和PEO复合修饰聚氨酯,不仅减少了材料表面血小板粘附量,而且减少了材料表面血栓的形成量.     

聚氨酯弹性体相分离程度的研究

热塑型聚氨酯弹性体(TPUE)的动态力学性能和热性能研究已有许多报导,但多集中于弹性体的链结构及其组成等方面,本文则侧重于研究聚醚氨酯(ET)和聚酯氨酯的相分离过程及其程度,考察硬段含量(W_h)和软段分子量(M_(n·3)等因素对微相结构的影响。     

嵌段聚醚聚氨酯-酯热塑性弹性体的合成和性质

 本文用对苯二甲酸双羟基乙二醇酯及其二聚体作扩链剂,合成了一系列聚醚聚氨酯-酯嵌段共聚物(PEUE),并用热分析法、动态力学分析、应力-应变等方法对所合成的聚氨酯材料进行了形态结构和性能关系的研究,结果表明:这类聚氨酯弹性体由于硬段具有较好的结晶性,致使材料的力学性能得到提高;另外,由于硬段酯基与软段聚醚的相互作用,材料的相容性有所改进.     

聚氧乙烯功能基复合修饰聚氨酯合成及其血液相容性研究（Ⅱ）—聚氨酯—接枝

采用以碘酸基为末端基的聚氧乙烯（PEO）接枝聚醚氨酯和氨基酸反应,将赖氨酸（Lys)和酪氨酸（Tyr)通过PEO为“间隔臂”固定在聚醚氨酯上,制备了氨基酸和PEO复合修饰的聚醚氨酯PEU－g-PEO-SO2Lys和PEU－g-PEO-SO2Tyr。通过血小板粘附试验对材料的体外抗凝血性进行 了初步评价。研究结果表明,采用具有选择性吸附纤溶酶原功能的赖氨酸和PEO复合修聚氨酯,不仅减少了材料表面血小板粘附量,而且减少了材料表面栓的形成量。     

软硬段对聚氨酯弹性体结构性能的影响

采用本体聚合和溶液聚合两种方法,合成了一系列用聚乙二酸丁二醇酯二醇作为软段的聚氨酯弹性体。研究了硬段含量和聚醚添加量对聚氨酯弹性体综合性能的影响。利用红外光谱、热分析、力学性能测试、记忆回弹性能和耐水解老化实验等测试手段对样品进行了表征与分析。结果表明:硬段质量含量为31%~35%时,材料的力学性能较优,形状回复率可以达到75%~85%;软段中聚醚添加量在4%~5%(占软段的质量分数)时,弹性体具有较好的力学性能和耐水解性能。     

磺酸型聚氨酯离聚物的离子导电性能

本文以多种聚醚为软段，二异氰酸酯（ＭＤＩ和ＴＤＩ）为硬段，合成了多嵌段聚醚聚氨酯，以此聚氨酯为基材，与ＮａＨ及１，３－丙碳酸内酯反应，进一步合成了一系列不同离子化程度的阴离子型碳化聚氨酯离聚物，用交流阻抗谱仪测定了样品的阻抗谱，由此计算出样品的离子电导率。研究结果表明其他条件相同时，以聚乙二醇（ＰＥＧ）为软段的样品具有较高的离子电导率；以聚环氧丙烷（ＰＰＯ）为软段的样品次之，以聚四氢呋喃（ＰＴＭＯ）为软段的样品最低，对于离子化程度不同的聚氨酯离聚物以金属离子和烷氧单元之比为０．０５时导电性能最好。阳离子为Ｌｉ＋和Ｎａ＋的样品具有相近的离子电导率。     

软硬段对聚氨酯弹性体结构性能的影响

采用本体聚合和溶液聚合两种方法,合成了一系列用聚乙二酸丁二醇酯二醇作为软段的聚氨酯弹性体。研究了不同硬段含量和聚醚添加量对聚氨酯弹性体综合性能的影响。利用红外光谱,机械性能测试、热分析、耐水解老化实验和记忆回弹性能等测试对样品进行表征与分析。结果表明:当硬段含量为33%～34%,软段中聚醚添加量为4%～5%(占软段的质量分数)时,弹性体具有较好的力学性能和耐老化性能,弹性回复率可维持在80%～85%。     

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。     

Polycarbonate-based polyurethane elastomers: temperature-dependence of tensile properties

Novel polyurethane thermoplastic elastomers were prepared from polycarbonate diols, butane-1,4-diol (chain extender) and hexamethylene diisocyanate. They differ in the kind of macrodiol used and the ratio of macrodiol to chain extender OH groups (hence, in hard segment contents). The tensile properties of the elastomers at low and elevated temperatures were determined and discussed with regard to polyurethane composition and polycarbonate diol structure.     

Synthesis and characterization of bismaleimides derived from polyurethanes

A series of novel bismaleimides (BMIs) were prepared from maleic anhydride and polyurethane prepolymers based on MDI (4,4′-diphenylmethane diisocyanate) and polyether and polyester diols with various chain lengths. All the BMIs were characterized by IR, ¹H-NMR, and elemental analysis. DSC studies indicated that the thermal polymerization of the BMIs could be carried out in the temperature range of 102–245°C, and that curing behavior was significantly affected by the molecular weight of the BMIs. The crosslinked BMI elastomers showed good mechanical properties and much better thermal stability than that of the traditional polyurethane elastomers. The glass transition temperatures, mechanical, and dynamic mechanical properties were dependent on the types of polyols used and the resultant crosslink densities due to various chain lengths of the BMIs. © 1994 John Wiley & Sons, Inc.     

聚碳酸亚丙酯-聚醚聚氨酯的合成与性能

本文报道用CO2与环氧丙烷共聚产物聚碳酸亚丙酯和环氧丙烷均聚物来制备聚氨酯（PPCPOPU）弹性体。探讨了这类弹性体的最佳合成方法，考察了异氰酸酯基与羟基的比值；扩链交联剂用量等因素对弹性体的力学性能的影响。研究了弹性体的形态结构及其性能对配比的依赖关系。发现聚碳酸亚丙酯的耐热性因聚氨酯的形成而得到较大的改善，并发现该类弹性体具有优异的耐水性能。     

聚碳酸亚丙酯聚氨酯的合成与性能

用ＣＯ２与环氧丙烷共聚产物聚碳酸亚丙酯制备出聚氨酯（ＰＰＣＰＵ）．同时探讨了ＰＰＣＰＵ最佳合成方法,考察了异氰酸酯基与羟基的比值、扩链交联剂用量等因素对其力学性能的影响．研究了ＰＰＣＰＵ的形态结构及其性能对配比的依赖关系．发现聚碳酸亚丙酯的耐热性因聚氨酯的形成而得到较大的改善,并发现该类材料具有优异的耐水性能．     

X-ray shielding polyurethanes: Synthesis and characterization

Synthesis and characterization of X-ray shielding thermoplastic polyurethane elastomers which are capable of blocking harmful radiation emitted by various sources are reported. X-ray shielding capability was generated in the polymer by covalently binding iodine atoms in a monomer and polymerizing it with other monomers such that the resultant polymer has the capability of shielding X-radiation. For rendering X-ray shielding capability to the polyurethane, Bisphenol-A (BPA) was iodinated to 4,4′-isopropylidinedi-(2,6-diiodophenol) (IBPA) and it was used as a chain extender during the synthesis of polyurethane. Polyurethanes were synthesized by reacting 1,6-diisocyanatohexane and IBPA with two different polyols, namely, poly(tetramethylene glycol) and poly(hexamethylene carbonate) diol. X-ray shielding polyurethanes (XPU) were characterized by infrared spectroscopy, thermogravimetry, dynamic mechanical analysis, energy-dispersive X-ray analysis, gel permeation chromatography, and X-radiography. Studies showed that by effectively changing polyol from polyether to polycarbonate, XPUs having different physicomechanical properties could be manufactured. Furthermore, these polyurethanes were also found to be noncytotoxic to L929 fibroblast cell lines. X-ray images revealed that the incorporation of IBPA has rendered X-ray opacity to the polyurethanes which are several times higher than the aluminum wedge of equivalent thickness. The materials are sufficiently flexible and rubbery, so can be used as coatings, films, or sheets for applications in energy sector, power-generating nuclear power plants, defense sector (bunkers for army personnel), medical applications (X-ray diagnostic and CT scanner rooms, gamma radiation therapy of cancer), etc.     

1,5-萘二异氰酸酯与1,4-丁二醇基为基质的多嵌段聚氨酯弹性体的合成与性能

利用 1 ,5_萘二异氰酸酯 (NDI)和 1 ,4_丁二醇 (BDO)为均匀硬质分子单体 ,与不同软质分子单体 (聚醚、聚酯、聚硅氧烷 )缩合制备多嵌段聚氨酯弹性体 ,详细研究了硬嵌段相 (NDI)弹性体的结构与性能间的关系 ,发现随着硬嵌段相长度的增加 ,或者氨基甲酸酯中胺基与聚醚、聚酯、聚硅氧烷中软段氧原子间氢键的减弱 ,都导致微相分离程度的增加 ,造成聚合物熔点和熔化热的升高。硬嵌段相熔化的多峰行为是由于形成了NDI/BDO半微晶区 ,在退火时转变为更加有序的结晶微区 ,当温度高于 1 80℃时 ,由于氢键的断裂 ,NDI/BDO硬嵌段发生分解反应 ,该过程源于不很有序的硬嵌段半结晶微区。当温度高于 2 5 0℃时 ,发生快速的分解。在动态力学行为方面 ,NDI基聚醚弹性体比其它硅氧烷基的弹性体展示了更高的硬嵌段区的稳定性 ,同时 ,在使用温度范围内 ,也显示出最高的储能模量值 ,表明刚性对温度的依赖性 ,以及NDI/BDO硬嵌段中活性填料的显著影响     

Infrared Spectra and Structure of Polyurethane Elastomers from Polytetrahydrofuran,Diphenylmethane-4, 4′-diisocyanate,and Ethylenediamine

Abstract

The infrared spectra (4000–650 cm^?1) of a series of polyurethane elastomers synthesized from polytetrahydrofuran, diphenylmethane-4,4′-diisocyanate, and ethylenediamine were examined. By comparing the spectra with those of the constituent polytetrahydrofuran and of the model compounds for the hard segments of the elastomers containing the urea, urethane, and diphenylmethane groups, most of the stronger bands could be assigned with reasonable assurance to the vibrations of each constituent part. The frequencies of the urea and the urethane characteristic bands correspond to complete association of the polar groups in the polymers. The spectral changes produced by uniaxially stretching polyurethane films can be interpreted as due to the induced crystallization of the polyether blocks in the elastomer, which remain amorphous in the undistorted state. Polarization measurements on stretched samples confirmed that the polyether chains are oriented parallel to the direction of the stretch.     

Comparison between properties of polyether polytriazole elastomers and polyether polyurethane elastomers

In order to explore the application of click chemistry in the field of elastomer materials, the comparison between the properties of polyurethane and polytriazole elastomers has been carried out. Propargyl‐terminated ethylene oxide‐tetrahydrofuran copolymer (PTPET) has been prepared from the ethylene oxide‐tetrahydrofuran copolymer (PET) by end modification. Using polyisocyanate N100 and polyazide compounds as cross‐linkers, PET polyurethane and PTPET polytriazole elastomers have been prepared through urethane and copper‐catalyzed azide‐alkyne huisgen [3 + 2] dipolar cycloaddition reactions, respectively. Mechanical properties indicate that, to be different from those of polyurethane elastomers, the modulus E and stress σ_b of polytriazole elastomers increase at first, and then decrease with the increase in R. At around the stoichiometric ratio, the modulus E and stress σ_b reach a maximum, and the strain ε_b reaches a minimum. Swelling tests demonstrate that the M_c of polytriazole elastomers has a minimum value at the stoichiometric ratio. The dynamic mechanical analysis indicates that both polyurethane and polytriazole elastomers have the same glass transition temperature of ?64°C, although polytriazole elastomers exhibit lower dissipation factor tan δ. Thermal analysis shows that polytriazole elastomers have better thermal stability than polyurethane elastomers. Copyright © 2014 John Wiley & Sons, Ltd.     

Comparison of the characteristics of polyurethane elastomers based on DMC- and traditional polyethers

The results of the study of replacement of traditional polyether polyols with DMC polyols based on the new DMC technology in formulas of polyurethane (PU) elastomer adhesives and sealants are presented. It is shown that the physical and mechanical characterisrics of PU elastomers are improved in many cases.