光/潮气双重固化聚氨酯涂层的制备及性能研究

以甲苯-2,4-二异氰酸酯(TDI)和二乙醇胺(DEOA)为原料一步法合成了超支化聚氨酯,对其改性制备了光固化超支化聚氨酯丙烯酸酯(HPUA)和一系列双重固化(UV/潮气)超支化聚氨酯丙烯酸酯(DHPUA),使用傅立叶红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)以及凝胶色谱(GPC)对其分子结构进行了表征.并以其为预聚物制备光固化涂层,通过对双重固化涂层的表面形貌、热性能和物理性能的研究,结果表明,超支化双重固化涂层经过潮气固化后,涂层表面的粗糙度随着树脂中硅氧烷端基的含量的增加先下降后上升;超支化双重固化涂层的物理性能和热稳定性都随着树脂中硅氧烷端基的含量的增加而提升.     

紫外光固化粉末涂料

紫外光（UV）固化粉末涂料综合了传统粉末涂料和辐射固化技术诸多优点，是涂料工业的前瞻性产品。本文介绍了紫外光固化粉末涂料的配制，固化机理，涂装工艺及潜在应用，并对其最新研究进展进行了综述。     

红外光谱法测定端羟基聚丁二烯(HTPB)胶粘体系的固化度

介绍用红外光谱法测定端羟基聚丁二烯（HTPB）胶粘体系固化度的原理及方法，并对端羟基聚丁二烯胶粘体系固化过程进行监控，分析了一定温度下胶粘体系的固化度与固化时间，以及相同固化时间内胶粘体系的固化度与固化温度之间的数学关系。     

耐热芴型环氧树脂的非等温固化动力学

合成了9,9’-二[4-(2,3环氧丙氧基)苯基]芴,并以4,4’-二氨基二苯砜胺为固化剂,用非等温DSC法研究了其固化动力学,用Flynn-Wall-Ozawa法和Friedman法确定了固化动力学参数,用动力学模拟推测了固化机理函数,并用TGA法对等温固化树脂的耐热性进行了表征。结果表明:双酚芴环氧固化反应的表观活化能约63.86 kJ/mol,扩散因子为3.80×104s-1,反应级数为1.57;固化反应为枝状成核的自催化反应;等温固化后的环氧树脂于400℃开始分解,700℃时残碳率为41.73%。     

双马来酰亚胺树脂固化过程的红外光谱分析

利用傅里叶变换红外光谱法研究双马来酰亚胺树脂固化过程中的结构变化,认为双马来酰亚胺树脂固化反应分两进行,第一步是低温下的“ENE”反应,第二步是高温下的Diels-Alder反应,树脂第一步固化反应达到一定程度后,要进一步提高固化反应程度,必须提高温度才能使第二步固化反应发生。     

辐射固化材料的现状和某些进展

介绍近年来UV/EB固化材料的发展进展,其中包括北美、欧洲、日本的发展概况和重大的新进展:(1)稀释单体和预聚体;(2)水基UV/EB固化;(3)阳离子光固化;(4)辐射固化粉末涂料;(5)复合固化体系;(6)UV固化纳米涂料;(7)光引发剂;(8)计算机直接制版.     

电子束固化环氧树脂的物理特征及其分析

分析了环氧树脂电子束辐射固化的物理特征 ,电子束辐射固化过程受活性中心扩散控制 ,整个固化区域由片层状结构组成 .与电子能量沉积分布相对应 ,环氧树脂辐射固化度的最高值是在一定深度而不是在辐射表面出现 .对电子束辐射环氧树脂体系的固化过程进行了模型解释 ,固化区域大小主要由电子的能量传递范围和浓度决定 ,反应活性中心的扩散作用影响较弱     

辐射固化涂层技术的最新发展

对辐射固化涂层技术的最新发展作了全面的问题。     

树枝形大分子/环氧树脂体系固化反应动力学研究

用示差扫描量热仪(DSC)对树枝形大分子PAMAM/双酚-A型环氧树脂体系的固化反应动力学过程进行了分析。通过Kissinger法求得体系固化反应的表观活化能ΔE为59.78kJ/mol,通过Crane法求得体系的固化反应级数n=0.91,并计算出了反应速率常数k和不同升温速率下的频率因子A。根据动态DSC数据确定体系合适的固化反应温度为80~90℃,后固化温度为140℃。     

有机硅改性丙烯酸环氧单酯光-热混杂固化体系的表面性能

以有机硅改性丙烯酸环氧单酯为树脂配制了一系列紫外光-热混杂固化体系.通过FTIR表征了光-热固化过程双键和环氧特征吸收峰的变化.研究了不同的稀释剂对光固化和光-热混杂固化膜的凝胶率、吸水率、表面水接触角等性能的影响,并用能谱仪(EDS)测试了固化膜表面硅元素的含量.结果表明:光固化膜的凝胶率低于86.5%,而光-热混杂固化膜的凝胶率在97.0%左右.与丙烯酸环氧单酯光-热固化体系相比,有机硅改性丙烯酸环氧单酯光-热固化膜的表面水接触角有显著提高,由62.53°提高到99.27°,EDS测试也表明有机硅有富集于固化膜表面的特性.     

含羧基嵌段的离聚体的合成及其性能研究

合成了羧基有序分布和羧基无序分布的两类光固化水性聚氨酯丙烯酸酯 (PUA)的离聚物 ,研究了其光固化反应动力学 ,并测定其预聚物分散液的性能和固化膜的性能。     

A novel type of Si-containing poly(urethane-imide)s: synthesis, characterization and electrical properties

A novel type of a Si-containing poly(urethane-imide) (PUI) was prepared by two different methods. In the first method, Si-containing polyurethane (PU) prepolymer having isocyanate end groups was prepared by the reaction of diphenylsilanediol (DSiD) and toluene diisocyanate (TDI). Subsequently the PU prepolymer was reacted with pyromellitic dianhydride (PMDA) or benzophenonetetracarboxylic dianhydride (BTDA) in N-methyl pyrolidone (NMP) to form Si-containing modified polyimide directly. In the second method, PU prepolymer was reacted with diaminodiphenylether (DDE) or diaminodiphenylsulfone (DDS) in order to prepare an amine telechelic PU prepolymer. Finally, the PU prepolymer having diamine end groups was reacted with PMDA or BTDA to form a Si-containing modified polyimide. Cast films prepared by second method were thermally treated at 160 °C to give a series of clear, transparent PUI films. Thermogravimetric analysis indicated that the thermal degradation of PUI starts at 265 °C which is higher than degradation temperature of conventional PU, confirming that the introduction of imide groups improved the thermal stability of PU.To characterize the modified polyimides and their films, TGA, FTIR, SEM and inherent viscosity analyses were carried out. The dielectrical properties were investigated by the frequency-capacitance method. Dielectric constant, dielectric breakdown strength, moisture uptake and solubility properties of the films were also investigated.     

新型乙炔封端聚酰亚胺的制备及性能

用双酚A型二醚二酐(BPADA)和3-乙炔基苯胺(m-APA)进行缩聚反应合成了乙炔基封端的聚酰亚胺预聚体, 并对预聚体的熔体黏度、稳定性和热性能等进行研究. 结果表明, 此类预聚体具有较宽的加工窗口和较低的加工温度, 适合模压成型工艺制备树脂基复合材料. 预聚体经250 ℃固化后显示了优异的热性能, 动态力学分析显示其玻璃化转变温度为363 ℃, 在氮气和空气气氛下5%热失重温度分别为490和492 ℃.     

拒水型有机硅改性聚氨酯嵌段共聚物的合成与表征

以氨丙基硅氧烷偶联剂和端羟基聚二甲基硅氧烷(PDMS)为原料,合成了端氨丙基聚二甲基硅氧烷低聚物(SN2),并将其作为扩链剂,制备了有机硅-聚氨酯(Si-PU)嵌段共聚物.考察了聚氨酯预聚体的加料比(rNCO/OH)、SN2与聚氨酯预聚体的加料比(rNH2/NCO)对Si-PU嵌段共聚物溶液流变行为及其膜性能的影响.研究发现,该Si-PU共聚物的异丙醇溶液呈现较低的表观黏度及牛顿特性;成膜时,有机硅链段向表面迁移;膜表面对水的接触角达110°以上,且随着有机硅链段含量的增高而增大;共聚物膜的24 h吸水率较低(<1.5 wt%);但当有机硅链段含量过高时,吸水率反而增高.     

The effect of planar molecular orientation on the mechanical properties of rigid-chain polymide films

The effect of biaxial orientation on the mechanical properties and supramolecular structure of the films based on rigid-chain polyimides and copolyimides was studied. The films were oriented in two different ways: by hot drawing and by cold drawing at the prepolymer stage and the subsequent cyclization according to the specified temperature regime. It was shown that the curing of the precursor films after their preliminary biaxial drawing is accompanied by self-orientation, although its degree is well below that after uniaxial drawing under the same conditions. As compared with homopolyimide films, the films based on rigid-chain copolyimide exhibit a lower tendency toward orientation under biaxial drawing. The reasons for such behavior are discussed.     

Graft interpenetrating polymer networks of polyurethane and epoxy. II. Toughening mechanism

Graft interpenetrating polymer networks (graft-IPNs) of polyurethane (PU) and the diglycidyl ether of bisphenol A (epoxy) were prepared by first grafting excess PU prepolymer to the epoxy and then simultaneously polymerizing the PU prepolymer and epoxy. The fracture properties, at high shear rate (e.g., impact) and low shear rate (e.g., pseudostatic tensile fracture energy measurement) of these graft-IPNs exhibit opposite behavior. Although dispersed rubber particles can enhance the Izod impact strength, toughening of the matrix of graft-IPNs was found to be the main contribution. In contrast, it was found that a heterogeneous morphology with suitably dispersed rubber domains of appropriate size as well as the toughness of the matrix are requirements for effectively increasing the fracture energy at low shear rate. A reinitiating crack in the plastic matrix is proposed as the main toughening mechanism and can be invoked to interpret the fracture behavior at high and low shear rates of the graft-IPNs.     

Poly(ether‐imide) and related sepiolite nanocomposites: investigation of physical,thermal, and mechanical properties

Novel poly(ether‐imide) and sepiolite nanocomposites were synthesized based on a unique diamine monomer with the aim of improving physical and mechanical properties of final polyimide films. The diamine was polycondensed with 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride to produce related poly(ether amic acid) prepolymer. Pure poly(ether‐imide) and nanocomposite films were prepared via thermal imidization process of poly(ether amic acid). Coexistence of ether, pyridine, and phenylene functional groups in the diamine chemical structure resulted in flexible polyimide films with significant thermal, physical, and mechanical properties. Thermal stability, glass‐transition temperature, dimensional stability, and tensile properties of polymer and nanocomposites were studied and compared. Morphology of nanocomposites was also investigated using scanning and transmission electron microscopic methods to study the distribution and dispersion behavior of sepiolite nanofibers in the polyimide matrix. By introduction of sepiolite nanoparticles, overall improvement of properties was observed in respect to pure polyimides. Copyright © 2015 John Wiley & Sons, Ltd.     

用封端预聚物制备聚氨酯-丙烯酸酯水分散液

采用具有烯醇结构的封端剂，用反应活性较高的芳香族异氰酸酯制备了聚氨酯-丙烯酸酯(PUA)水分散液。红外光谱分析和涂膜性能测试结果表明，封端后的聚氨酯预聚物在水中可以解封，所制备的PUA膜的性能优于在水中难于解封的封端剂制备的PUA。比较了用预聚物分散法和核壳反转法制备的封端型PUA水分散液的特性。     

The effects of altered reaction conditions on the properties of anionic poly(urethane-urea) dispersions and films cast from the dispersions

Aqueous anionic polyurethane (PU) dispersions were synthesised from a polyester polyol, isophorone diisocyanate and α,α-dimethylol propionic acid using the prepolymer mixing process. Samples were neutralised by the addition of triethyl amine. The polymer chains were dispersed in water and extended with 1,2-ethylene diamine. The differences in the dispersion characteristics and the mechanical properties of the polymer films cast and dried from the dispersions caused by altered reaction conditions were determined.The reaction conditions proved to affect both the colloidal properties of the dispersions as well as the mechanical properties of the films. The neutralisation, the dispersion and the chain extension methods had all an influence on the average size of the formed PU particles. For the films, a change in the mechanical properties and probably in the amount of hard and soft domain separation was also observed. A good control over the properties was obtained by selecting the reaction parameters carefully. In particular, the dispersion method in which the prepolymer solution was added to water and not vice versa led to a considerably lower viscosity during the dispersion process. Thus a wider choice of raw materials was facilitated.     

WPU预聚体中羧基含量及其位置对树脂的粒径及其耐水性之影响的研究

本文先将马来酸酐与多元醇作用，然后再与其它单体反应，合成了含有羧基的聚氨酯预聚体，并用丁酮稀释后，在普通搅拌条件下使预聚体分散于三乙醇胺的水溶液中，合成出以水为分散介质的聚氨酯分散体系（WPU）。并通过改变羧基在预聚体中的含量和位置，发现随着羧基含量的增加，WPU的粒径减小，而耐水性下降。同时发现，在一定的羧基含量下，同侧羧基相比，端羧基更有利于预聚体的乳化，制得的WPU不仅颗粒较小，而且树脂耐水性明显优于侧基羧预聚体制备的WPU，从而提出羧基的运动自由度是影响羧基乳化活性和树脂耐水性的重要因素。