环氧固化剂乳液的制备研究

本研究采用一种两亲性物质合成预聚物,使改性多胺固化剂分散在水中,形成稳定的乳液。研究了预聚物合成的最佳催化剂用量为6‰,最佳反应温度为75℃。使用此固化剂乳液固化的环氧树脂清漆漆膜具有良好的外观和力学性能。     

封闭型多异氰酸酯固化交联剂的合成

合成了一种低温解封的全封闭型多异氰酸酯固化交联剂,考察了合成反应速率和最终涂膜性能。实验发现:选择TD I-80和TMP制备预聚物,将TMP以连续滴加的方式加入TD I中,并控制在70℃反应2h,能得到理想的预聚物;以甲基异丁基甲酮为溶剂,采用乙二醇乙醚对预聚物进行封闭,在80℃封闭反应2~3h可得完全封闭型固化剂。最后将固化剂与二乙醇胺改性的环氧树脂E-20复配并进行电泳,得到的涂膜在150℃烘烤30m in,硬度可达3H~4H,综合性能优良。     

降低聚氨酯固化剂中游离TDI含量的方法研究

采用工艺与装备一体化的思路进行了TDI-TMP聚氨酯固化剂的合成与分离研究。研究了适合在薄膜蒸发器中进行游离TDI分离的聚氨酯预聚物的合成工艺,讨论了TDI/TMP的配比、反应温度和加料方式对TDI-TMP预聚物合成工艺的影响。研究了高真空两级薄膜蒸发器分离预聚物中游离TDI的分离工艺,讨论了进料速率、二级蒸馏温度、二级绝对压力和二级刮板转速对分离效果的影响。研究表明:在TDI与TMP质量比在5:1,反应温度在50℃,反应时间5h的合成条件下,得到的预聚物分子量小、黏度低、流动所需温度低,适合在薄膜蒸发器中进行游离TDI的分离。优化的分离工艺条件是进料速率为1.6kg·min-1,二级蒸馏温度为170℃,二级蒸馏绝压为80Pa,二级刮板转速为180r·min-1。合成与分离后的聚氨酯固化剂色泽浅、游离TDI含量和-NCO含量符合设计要求。     

红外光谱法研究TDI—TMP固化剂的合成过程

采用傅里叶变换红外光谱分析技术对甲苯二异氰酸酯（TDI）与三羟甲基丙烷（TMP）固化剂合成反应过程中的聚氨酯预聚物进行表征,分析原料谱图和合成过程中预聚物谱图,确定反应进程,探讨反应机理。TDI—TMP合成过程的红外光谱分析结果表明,虽然TMP是一种结构紧密空间不舒展的多元醇,但是在TDI大量过量时,-OH基在低温下通过延长反应时间是可以基本反应完全的。在优化的合成工艺条件下得到了分子质量小、黏度低的理想预聚物,该预聚物适合在薄膜蒸发器中进行游离TDI的分离。     

聚氨酯固化剂合成工艺的研究

研究了适合在薄膜蒸发器中进行游离TDI分离的TDI-TMP聚氨酯固化剂的合成工艺。讨论了合成过程中甲苯二异氰酸酯（TDI）与三羟甲基丙烷（TMP）投料比、反应温度、加料方式对预聚物性能的影响。试验表明：在TDI与TMP质量比在5∶1,反应温度在50℃,反应时间5 h的合成条件下,得到的预聚物相对分子质量小、黏度低、流动所需温度低,适合在薄膜蒸发器中进行游离TDI的分离,分离后的聚氨酯固化剂色泽浅、游离TDI含量和—NCO含量符合设计要求。     

TDI/TNP 预聚物固化型自干氨基醇酸树脂漆

讨论了葵花油改性醇酸树脂的合成、TDI／TMP预聚物固化剂的制备及氨基树脂的选择,确定了氨基树脂和醇酸树脂与固化剂的配比,简介了自干型氨基漆的技术指标。     

水性聚氨酯涂料的研究

以预聚物混合法制备水性聚氨酯分散体,合成了封端的水性聚氨酯固化剂。用其配制的水性聚氨酯烘干清漆具有优良的耐水性和物理机械性能。     

聚氨酯固化剂合成研究

提出了要想在薄膜蒸发器中分离出TDI,得到合格的聚氨酯固化剂产品,需要从合成固化剂入手,相对分子质量小、反应完全的聚氨酯固化剂更适合在薄膜蒸发器中进行分离,研究探讨了聚氨酯合成工艺。研究显示:分段升温反应有利于降低固化剂黏度;TDI和TMP的配比越大,固化剂黏度越小,但为了给后处理减小蒸馏负荷,确定TDI/TMP的质量比为4.6∶1;研究了酸碱度对反应的影响,反应体系偏碱性加速副反应,酸性较强也会加速副反应,研究显示加入少量磷酸有利于黏度的降低,提出了副反应抑制机理。合成的预聚物在分离过程中未见堵塞设备现象。     

高装饰性改性醇酸家具涂料

介绍了用苯甲酸改性的含羟基醇酸树脂和甲苯二异氰酸酯(TDI)预聚物的合成工艺,以及由二者制成醇酸型聚氨酯涂料的方法;讨论了合成的醇酸树脂、TDI预聚物、固化剂种类和用量、溶剂、助剂和颜填料对涂料及涂膜性能的影响。制备得到的改性醇酸家具涂料成本不仅比聚酯涂料低,而且其涂膜的光泽高、丰满度好、硬度高、干性好,施工性能也有所改善。     

MDI改性聚葑酯固化剂的研制

合成一种聚合多元醇，并以此聚合多元醇为预聚物骨架，用MDI取代部分TDI，合成一种新型聚氨酯固化剂，其性能接近TDI-TMP加成物。讨论了影响改性固化剂性能的各种因素，试验结果表明：MDI／TDI比例为1／4～1／3时，综合性能较好。     

Blocked isocyanate-terminated prepolymers in a delayed-cure durable-press finish for wool. Influence of isocyanate and blocking group structure on reactivity

A series of prepolymers containing terminal blocked isocyanate groups was prepared by reaction of isocyanate-terminated prepolymers [derived from a poly(propylene oxide) diol (MW = 2000) or a triol (MW = 3000) and different diisocyanates] with various blocking agents. Their curing rates with a polyepoxide crosslinking agent were measured to assess their suitability for a delayed-cure durable-press treatment for wool. The curing rates varied over a wide range, but commonly used blocking groups such as phenols, caprolactam, β-diketones, and alcohols were not sufficiently reactive for the intended application, although others, e.g., oximes and certain blocking agents containing a basic center such as N,N-diethylhydroxylamine, hydroxypyridines, and hydroxyquinolines, had the required reactivity. Blocking by 1,3-dipolar cycloaddition of nitrones was examined, but the reactivities were too low. Prepolymers containing blocked aromatic isocyanates were more reactive than those containing blocked aliphatic isocyanates. Difunctional butanone oxime-blocked pre-polymers cured slightly more slowly than analogous trifunctional prepolymers.     

聚醚二元醇与异氰酸酯封端反应的研究

以聚醚二元醇和二苯甲烷二异氰酸酯(MDI)为原料合成预聚体,分别以丙酮肟、甲乙酮肟、丁二酮肟和硝基甲烷作为封闭剂,制备了二苯甲烷二异氰酸酯固化剂。用于阴极电泳涂料,以降低固化温度。利用化学滴定、红外光谱和热重分析(TG)等分析手段对预聚体和异氰酸酯固化剂进行了表征和分析。实验结果表明解封反应时间及解封温度与封闭剂种类有关,甲乙酮肟封闭的异氰酸酯固化剂的解封温度最低,为130℃,解封时间为20 min。     

Syntheses and properties of UV-autocurable prepolymers. Semicrystalline urethane-multiacrylates

A series of UV-autocurable urethane-multiacrylate prepolymers, which were semicrystalline and showed melting points in the region of 40–50°C, was synthesized. Also, the effects of curing temperature and acrylic functionality on the structure and properties of the cured films were investigated. These prepolymers are solids and opaque at room temperature. In general, UV curing reactions of solid prepolymers are less efficient when compared with those of liquid prepolymers. UV curing reactions at curing temperatures below the melting point (T_m) of the prepolymers produced semicrystalline urethane-multiacrylate cured films. On the contrary, UV curing reactions above T_m destroyed the crystalline phase of the prepolymers and improved the transparency of the cured films. The films cured below T_m of the prepolymers had higher both breaking strength and Young's modulus, and a higher glass transition temperature (T_g), but a lower elongation at break than those cured above T_m. Such curing temperature effects were attributed to the retention or disappearance of the crystalline structure of the prepolymers during UV curing reaction. At curing temperatures below T_m, an increase in acrylic functionality of the prepolymer resulted in a fast curing rate and a higher crosslinking density of the cured films. Therefore, an increase in acrylic functionality of the prepolymers gave cured films with higher breaking strength and Young's modulus, but a lower elongation at break.     

封闭型异氰酸酯在粉末涂料中的应用

综述了封闭型异氰酸酯在粉末涂料中的应用,包括封闭剂的类型、预聚物的结构及其对性能的影响。介绍了封闭型异氰酸酯在制备低光泽粉末涂料和水分散性粉末涂料中的应用。     

Introduction of covalently bonded phosphorus into aqueous‐based polyurethane system via postcuring reaction

Anionic aqueous‐based polyurethane (PU) dispersions were derived from a water dispersion process of carboxylic groups containing PU prepolymers together with a neutralization and a chain extension. These PU prepolymers were prepared from a conventional polyaddition of isophorone diisocyanate, polypropylene glycol‐1000, and dimethylolpropanic acid. A covalently bonded phosphorus was introduced into PU by a phosporus‐containing curing agent. A series of phosphorus and multi‐aziridinyl groups containing curing agents were synthesized for this purpose. Each of them served in a dual‐function capacity as a postcuring agent for the anionic aqueous‐based PU system. The resulting postcured PU exhibited improvements in its mechanical, physical, and thermal properties; furthermore, postcured PU synergistic flame inhibition was also observed due to the presence of nitrogen and phosphorus content in the process. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2499–2509, 1999     

Preparation and properties of novel polyurethane insulating coatings based on glycerin‐terminated urethane prepolymers and blocked isocyanate

Novel polyurethane insulating coatings were prepared from the reaction of glycerin‐terminated polyurethane prepolymers (GPUPs) and a blocked isocyanate curing agent (BIC). The GPUPs were prepared from the reaction of one equivalent of polycaprolactone polyol (CAPA 210) with an excess amount of 4,4′‐methylene bis(phenyl isocyanate) (MDI) and subsequent reaction of the NCO‐terminated polyurethane with glycerin. The BIC was prepared from the reaction of trimethylol propane (TMP), toluene diisocyanate (TDI) and N‐methylaniline (NMA). The polyols and curing agent were characterized by conventional methods while the curing condition was optimized via gel content measurements. The curing kinetics of the polyurethane coating were investigated and the kinetic parameters derived. The crosslink densities of the samples were determined via the equilibrium swelling method, using the Flory–Rehner equation. The relationships between the crosslink density and the electrical, physical, mechanical and dynamic mechanical properties of the coatings were also studied. Copyright © 2005 Society of Chemical Industry     

A cure study on alumina trihydrate reinforced allylester resins by differential scanning calorimetry

Allylester prepolymers were synthesized by transesterification, and curing kinetics of alumina tihydrate reinforced allylester resins was studied by means of a differential scanning calorimetry dynamic experiment. The activation energies and the frequency factors of the reinforced allylester prepolymers were estimated by means of Ozawa's and Kissinger's methods. The values determined from the Ozawa method are higher than those from the Kissinger method. The peak exotherm temperature of reinforced allylester resin was shifted to a lower temperature as the concentration of curing agent increased. The peak exotherm temperature as the concentration of curing agent increased. The peak exotherm temperature of reinforced allylester resin was, however, shifted to a higher temperature as the content of alumina trihydrate increased. In the case of the dynamic experiment, both the activation energy and the frequency factor decreased as the concentration of curing agent was increased. Meanwhile, there exist minimum values of both the activation energy and th frequency factor with varying contents of alumina trihydrate.     

Isocyanate‐Free and Dual Curing of Smokeless Composite Rocket Propellants

Traditional composite rocket propellants are cured by treatment of hydroxyl‐terminated prepolymers with polyfunctional aliphatic isocyanates. For development of smokeless composite propellants containing nitramines and/or ammonium dinitramide (ADN), energetic binder systems using glycidyl azide polymer (GAP) are of particular interest. Polyfunctional alkynes are potential isocyanate‐free curing agents for GAP through thermal azide‐alkyne cycloaddition and subsequent formation of triazole crosslinkages. Propargyl succinate or closely related aliphatic derivatives have previously been reported for such isocyanate‐free curing of GAP. Herein, we present the synthesis and use of a new aromatic alkyne curing agent, the crystalline solid bisphenol A bis(propargyl ether) (BABE), as isocyanate‐free curing agent in smokeless propellants based on GAP, using either octogen (HMX) and/or prilled ADN as energetic filler materials. Thermal and mechanical properties, impact and friction sensitivity and ballistic characteristics were evaluated for these alkyne cured propellants. Improved mechanical properties could be obtained by combining isocyanate and alkyne curing agents (dual curing), a combination that imparted better mechanical properties in the cured propellants than either curing system did individually. The addition of a neutral polymeric bonding agent (NPBA) for improvement of binder‐filler interactions was also investigated using tensile testing and dynamic mechanical analysis (DMA). It was verified that the presence of isocyanates is essential for the NPBA to improve the mechanical properties of the propellants, further strengthening the attractiveness of dual cure systems.     

硅胶按键用耐磨聚氨酯树脂的制备与表征

聚氨酯由硬段和软段交替组成,具有良好的物理和机械性能,在硅胶按键保护涂料方面的应用越来越广泛.随着对涂层耐磨性能要求的提高,开发一种针对于硅胶按键表面保护的高耐磨聚氨酯树脂变得十分关键.用聚酯二元醇(相对分子质量580)、乙二醇(EG)、三羟甲基丙烷(TMP)、异佛尔酮二异氰酸酯(IPDI)为原料合成了端羟基聚氨酯预聚物,使用封闭型异氰酸酯作为固化剂交联固化制备聚氨酯薄膜和涂层.研究了聚氨酯薄膜的拉伸性能、热性能以及聚氨酯涂层的耐磨性能,并探讨了EG和TMP用量对聚氨酯薄膜的热性能以及力学性能的影响,重点研究了二者对聚氨酯涂层耐磨性能的影响.测试结果表明:当聚氨酯树脂中EG和TMP的羟基摩尔分数分别为35％ ～ 39％和20％时,聚氨酯涂层的耐磨性能较佳,适用于制备硅胶表面保护涂料.     

紫外光固化环氧豆油丙烯酸酯的制备与表征

将环氧大豆油与丙烯酸反应制备出环氧豆油丙烯酸酯预聚物,讨论了反应温度、反应时间、催化剂、阻聚剂的种类与用量对合成反应的影响,并用红外光谱对产物的结构进行了表征。研究结果表明其最佳反应条件是:催化剂三苯基膦,反应温度110℃,反应时间8h。该预聚树脂可用紫外光固化,其固化膜硬度达3H,且具有较好的柔韧性和附着力。