HDI缩二脲多异氰酸酯的合成

引　言ＨＤＩ缩二脲是指用ＨＤＩ(六亚甲基二异氰酸酯 ,ＮＣＯ— (ＣＨ2 ) 6—ＮＣＯ)和另一组分合成的具有缩二脲结构 (ＮＣＯ—ＮＨ—ＣＯ—ＮＨ— )的多异氰酸酯预聚物 ,属于脂肪族聚氨酯涂料广泛使用的固化剂之一 .脂肪族聚氨酯涂料因其具有其他类涂料无可比拟的耐候性和高装饰性 ,近年来在飞机蒙皮漆、汽车面漆、建筑外墙涂料等方面的应用越来越广泛 ,需求量逐步增加[1] .其中最广泛使用的固化剂是ＨＤＩ缩二脲多异氰酸酯 .生产该化合物的过程中 ,ＨＤＩ与水反应合成缩二脲反应体系的副反应非常多 ,产物组成很复杂 .如何控制反应过程 ,…     

The preparation of hybrid trimer by cyclo-oligomerization of TDI and HDI and its curing process with polyols to form elastic PU coating

The hybrid cyclic isocyanate trimer with appropriate functionality and good solvent tolerance which can be used as a building block to construct polyurethane (PU) coatings was prepared by cyclo-oligomerization of toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI). Among all the tested catalysts, the self-made catalyst 3-(trimethylammonio)propyl carbonate (Cat. 4) was found to possess enough catalytic efficiency to confirm the NCO conversion to reach about 50% with both high (1 wt%) and low (0.25 wt%) catalyst loading at low temperature (40°C). The IR and NMR results proved the formation of a hybrid trimer, while HPLC results showed hybrid TDI/HDI trimer predominated in the product and only trace amounts of TDI monomer (<0.5 wt%) and oligomer with higher degree of polymerization (DP) remained. Furthermore, the formed hybrid oligomer exhibited excellent solvent tolerance to benzene, chlorinated, and acetate solvents. Consequently, Cat. 4 was demonstrated to be a suitable catalyst for cyclo-oligomerization since it not only possessed enough catalytic efficiency at low temperature but also hardly resulted in higher DP oligomer. Furthermore, the curing process with PTHF-r-PEO polyol was conducted as a pilot experiment to form PU coatings at room temperature. The disappearance of NCO group in IR spectrum as well as higher storage modulus against loss modulus implied the successful curing process. The strain–stress test showed the high tensile strength of formed PU coating, whereas the rheological test and dynamic mechanical analyzer proved the formed PU coating was a typical elastic material with good crosslink structure. These results indicate the promising potential of formed PU made from hybrid TDI/HDI trimer for coating applications.     

Kinetics and mechanisms of catalyzed and noncatalyzed reactions of OH and NCO in acrylic polyol–1,6‐hexamethylene diisocyanate (HDI) polyurethanes. VI

Fourier transform infrared spectroscopy was used to study the kinetics of noncatalyzed and catalyzed polyurethanes. These studies show that for noncatalyzed acrylic polyol–hexamethylene diisocyanate (HDI) trimer reactions, the reactions between OH and NCO of HDI exhibit second‐order kinetics, with first‐order kinetics with respect to NCO and OH. On the other hand, when dibutyltin dilaurate (DBTDL) is used as a catalyst in acrylic polyol–HDI trimer reactions, the reaction rate is first order with respect to NCO and 0.5 order in OH and DBTDL concentrations. A mechanism for the catalyzed acrylic polyol–HDI trimer crosslinking reactions is proposed and it appears that an equilibrium involving associations between OH and DBTDL exists, resulting in the formation of an active anion, which interacts with NCO to generate polyurethanes. To further verify this mechanism, the influence of acidity on the reaction rate constant was investigated. When the acidity of the system is increased, retardation of urethane formation occurs. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2322–2329, 2002     

高性能、易分散水性多异氰酸酯固化剂的合成与应用研究

通过新型的氨基磺酸与多异氰酸酯（HDI三聚体）反应制备了一种高性能、易分散的水性多异氰酸酯固化剂.研究表明N,N-二甲基环己胺与氨基磺酸物质的量比为1.05、100℃反应4h,氨基磺酸用量在2.5％～3.0％,可以制备高性能、易分散的水性多异氰酸酯固化剂;通过与市场同类型产品进行比较,发现试验室制备的固化剂性能与市场化同类型产品相当.     

HDI三聚体合成研究

以一种Ｎ－羟基烷季铵碱为三聚反应催化剂，合成了以六亚甲基二异氰酸酯（ＨＤＩ）三聚体为主要成分多异氰酸酯固化剂，对合成条件下进行了探讨。     

亲水性多异氰酸酯固化剂的制备及其性能

采用聚乙二醇混合单甲醚与HDI三聚体反应制备了亲水性多异氰酸酯固化剂,考察了不同亲水性表面活性剂对改性多异氰酸酯亲水性的影响.结果表明,选用平均相对分子质量为500的聚乙二醇混合单甲醚作为亲水单体,n(NCO)/n(OH)为6:1,制备的亲水性多异氰酸酯固化剂具有较好的乳化效果.     

Synthesis of isocyanate microcapsules as functional crosslinking agent for wood adhesive

ABSTRACT

In this study, controlled-release isocyanate microcapsules were synthesized as functional crosslinking to slowdown the rate of cross-linking reactions. The isocyanate microcapsules were prepared by In-situ polymerization with polymethylene polyphenyl polyisocyanates (PAPI) as core and Urea formaldehyde resin as shell in oil-in-water emulsions. The particle size distribution, chemical structure, morphology, activity, and stability of the microcapsules were comprehensively characterized. Finally, the microcapsules were applied in a wood adhesive to prepare water-resistant plywood. The results showed that the size of the microcapsules was around 100 μm, the active content of NCO was about 23.5%, and the core content was approximately 80%. Compared with the stability of the bulk isocyanate, the stability of the isocyanate in microcapsules was significantly improved in the wood adhesive system. Furthermore, the isocyanate microcapsules showed highly efficient in plywood at different time, which indicated that isocyanate microcapsules could be controllable released in plywood applications.     

异氰酸酯/可发性酚醛树脂泡沫体的制备

采用端异氰酸酯聚醚预聚物与可发性酚醛树脂制备了新型泡沫体。通过ESI-MS光谱分析和泡沫物理力学性能测试研究了异氰酸酯基团与可发性酚醛树脂比例、异氰酸酯基团和三聚体相对含量、可发性酚醛树脂分子质量对泡沫体制备及性能的影响。结果表明:异氰酸酯基团与酚醛树脂质量比为40/100、三聚体质量分数17.33%、酚醛树脂聚合时间45min时,泡沫体的体积稳定性好,收缩率低;可发性酚醛树脂分子质量增加时,泡沫体的密度从60.16kg/m3增加到63.96kg/m3,基本保持稳定;其弯曲强度为0.2MPa,弯曲应变达到15%以上,远高于纯酚醛泡沫(6%)。在150℃下烘烤2h,泡沫体的质量损失为6%左右,体积变化为-5%左右。泡沫体的热稳定性优于聚氨酯泡沫,同时又有良好的韧性。     

Synthesis,characterization and self-crosslinking of glycidyl carbamate functional resins

Multifunctional glycidyl carbamate functional resins were synthesized, characterized, and self-crosslinked coatings were prepared and characterized. Coatings based on glycidyl carbamate (GC) functional oligomers are attractive because they combine polyurethane properties with epoxide reactivity. The glycidyl carbamate functional resins were synthesized via reactions of the biuret adduct and isocyanurate trimer of hexamethylene diisocyanate (HDI) with glycidol. Resins were characterized using gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy and ¹³C NMR spectroscopy. Coatings were prepared to study the self-crosslinking reaction without additional hardener. Self-crosslinked coatings had an excellent combination of solvent resistance, good hardness and high impact resistance. The glycidyl carbamate resin from the biuret isocyanate adduct (BGC) was found to be more reactive during cure than glycidyl carbamate from the isocyanurate isocyanate trimer (IGC) as determined by hardness, solvent resistance, and T_g measurements. Thermogravimetric analysis (TGA) of the resins did not show thermal decomposition below 250 °C.     

Effect of polyisocyanate hardener on adhesive force of waterborne polyurethane adhesives

A series of waterborne polyurethane (WBPU)/hardener adhesives were obtained from mixing of WBPU containing different types of polyol as a soft segment with aliphatic and aromatic polyisocyanates hardeners. By characterization of allophanate and biuret bonds formed from the reaction of hardener NCO with urethane/urea groups of WBPU using ¹HNMR spectroscopy. It was found that the optimum number ratio (molar ratio) of NCO group of hardener to urethane/urea group of WBPU that shows the highest adhesion force was depended on the type of hardener (aliphatic/aromatic polyisocyanate) and dimethylol propionic acid (DMPA) content (total content of urethane/urea groups); however independent of the type of soft segment (polyol) of WBPU. The optimum number ratio (molar ratio) of NCO group of aromatic polyisocyanate hardener to urethane/urea was higher than that of aliphatic hardener to achieve the highest adhesion force of WBPU. The adhesive force increased with increasing hardener content up to the optimum point and then decreased. Poly(tetramethylene adipate glycol) (PTAd) based WBPUs with aliphatic hardener show higher adhesive force than Poly(tetramethylene oxide glycol) (PTMG) and aliphatic hardener‐based WBPUs at the optimum number ratio (molar ratio) of NCO group of hardener to urethane/urea group of WBPU. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3663–3669, 2007     

聚氨酯弹性体的力学性能和热性能研究

研究了以ＨＤＩ异氰脲酸酯（ＨＤＩ三聚体）和ＨＤＩ缩二脲（Ｎ１００）与聚醚制得的聚氨酯弹性体的力学性能和热性能。结果表明,含异氰脲酸酯基的弹性体的拉伸强度和断裂伸长率高于缩二脲弹性体,而两者的弹性模量相当。此外,含异氰脲酸酯基的弹性体还有较好的热稳定性。     

HDI类多异氰酸酯固化剂合成研究进展

六亚甲基二异氰酸酯（HDI）是一种重要的脂肪族异氰酸酯单体。以其为主体制备的多异氰酸酯固化剂用于涂料和胶黏剂可使涂膜具有优异的耐候性、保光性和抗粉化性。由于结构中两个异氰酸根活性相同,其衍生物固化剂的合成较难控制,工艺复杂,生产过程难度大。综述了近年来以HDI缩二脲、HDI三聚体、HDI—TDI混合多聚体和HDI—TMP加成物为代表的几种重要的HDI类固化剂的合成研究进展、国外的生产工艺及国内在此领域存在的不足和需要解决的问题,旨在为国内企业的研发提供一定的参考。     

毒死蜱的微胶囊化及其长效毒杀性能

以异佛尔酮二异氰酸酯三聚体、二甲苯、毒死蜱为油相,聚乙烯醇、水、十二烷基磺酸钠为水相,通过界面聚合法,制备出高稳定性毒死蜱微胶囊悬浮剂。通过扫描电镜照片研究了微胶囊的表面形貌和平均粒径,用紫外分光光度法研究了微胶囊对毒死蜱的初期包封率及其释放特性;壁材及微胶囊的热行为通过热重分析进行了表征;用斜纹夜蛾3龄幼虫进行了生测初步试验。结果表明,微胶囊是平均粒径为10μm左右的球形颗粒;壁材热稳定性良好,微胶囊的初期包封率均高于95%,在低于45℃的水相中毒死蜱在微胶囊中能长期稳定储存,微胶囊化的毒死蜱具有持久的生物毒杀性。     

Thiourethane thermoset coatings from bio‐based thiols

Three bio‐based thiols were synthesized via the thermal thiol‐ene reactions between sucrose soya ester (SSE) and multifunctional thiols; then, thiourethane coatings were produced from these thiols and their coating properties were studied. A series of high bio‐renewable content thiol oligomers were synthesized according to the previously reported thermal thiol‐ene reaction. Fourier transform infrared spectra (FTIR) confirmed the complete consumption of the double bonds in SSE, and gel permeation chromatography confirmed the formation of high‐molecular‐weight oligomers. The viscosity of these oligomers remained low due to their compact and branched structures. Thermoset thiourethane coatings were prepared from these thiol oligomers and polyisocyanate trimer resins with dibutyltin diacetate as the catalyst. FTIR spectra confirmed the formation of the thiourethane group. However, coatings based on isophorone diisocyanate (IPDI) polyisocyanate resin showed a lower degree of cure because of the decreased resin mobility due to the rigid cyclohexane ring. Generally, all the coatings showed good adhesion to aluminum panels, and had high gloss. However, they exhibited low tensile strength, modulus and chemical resistance due to the flexibility of the fatty acid chain. Coatings based on more rigid IPDI‐based polyisocyanate showed higher T_g, hardness and direct impact resistance compared with the hexamethylene‐diisocyanate (HDI) based polyisocyanate counterparts. Thermogravimetric analysis results showed that coatings based on mercaptanized soybean oil have better thermal stability than those from di‐pentene dimercaptan or glycol di‐3‐mercaptopropionate. Two T_g values were found by both differential scanning calorimetry and dynamic mechanical thermal analysis of thiourethanes from HDI‐based polyisocyanate and di‐pentene dimercaptan or glycol di‐3‐mercaptopropionate based oligomers due to phase separation resulting from the poor compatibility between HDI‐based polyisocyanate and the respective oligomers. Copyright © 2011 Society of Chemical Industry     

HDI缩二脲配漆性能的影响因素

以HDI缩二脲为固化剂组分,研究了蓖麻油、羟基丙烯酸树脂和聚醚等羟基组分及乙酸乙酯、乙酸丁酯、甲苯和二甲苯4种溶剂对漆膜的影响,并与TDI-TMP型固化剂配漆进行了比较.结果表明,羟基组分和异氰酸酯固化剂组分是决定配漆后漆膜性能的主要因素;HDI缩二脲固化剂配漆后漆膜性能比TDI-TMP型固化剂配漆性能好,其附着力均为...     

Elastic recovery and creep properties of waterborne two-component polyurethanes investigated by micro-indentation

Polyurethane (PUR) films were obtained by casting waterborne formulation of polyhydroxylated polyacrylate resin and hexamethylene 1,6-diisocyanate trimer hardener. Conversion of the polyaddition reaction was followed by FTIR spectroscopy and appears independent of the NCO/OH stoichiometric ratio between HDI trimer NCO groups and polyhydroxylated polyacrylate OH groups (resin), but thermally activated. The crosslinked networks were investigated by swelling experiments and dynamic mechanical analysis. Calculated values of the average mass between crosslinks allowed explaining the evolutions of the conservation modulus and loss factor with NCO/OH stoichiometric ratio. Elastic recovery and creep behavior of the PUR films were investigated by micro-indentation. A four-element viscoelastic model was used to fit the indentation depth evolution during micro-indentation creep experiments. Results show that creep instantaneous elasticity is fully controlled by the network elasticity and thus by the NCO/OH stoichiometric ratio and that the ability of the network to dissipate energy remains high for non-continuous (NCO/OH ratio < 1) networks. On the other hand, for high NCO/OH ratios, it was shown that hard PUR networks exhibit creep properties and significant retardation times. Finally the evolution of indentation springback factor vs. indentation creep factor was determined, showing that instantaneous elastic recovery behavior increases as creep behavior decreases.     

木材用单组分湿固化聚氨酯胶粘剂的合成

以多亚甲基多苯基多异氰酸酯(PAPI)、聚丙二醇(PPG-N210)和催化剂2,2'-二吗啉二乙基醚(DMDEE)为主要原料合成了一种木材用单组分湿固化聚氨酯胶粘剂,分析了NCO含量、催化剂用量、扩链系数对胶粘剂性能的影响,并与国内外木材用胶粘剂进行了比较。结果表明,NCO质量分数为12.3%、催化剂用量为0.1%、扩链系数为0.2,制得的胶粘剂室温固化且固化速度快,粘接性能较好,适合于木材的粘接。     

双季铵碱催化HDI三聚反应动力学研究

以双季铵碱为催化剂,采用溶液聚合工艺对HDI进行三聚反应,气相色谱测定三聚反应体系中游离HDI的含量,研究了HDI三聚反应的动力学规律。结果表明,HDI三聚反应过程的前期反应阶段为三级反应,动力学方程为γ1=kc3,k=1.71×10-5h-1。     

Preparation and Characterization of Two-component Waterborne Poly-urethane Comprised of Water-soluble Acrylic Resin and HDI Biuret

A two-component waterborne polyurethane （2K-WPU） was prepared by mixing water-soluble acrylic resin and hexamethylene diisocyanate biuret, and then diluted for phase inversion with water. Compared with water-soluble acrylic resin, the phase inversion of 2K-WPU occurs at lower water content. It is indicated by TEM that 2K-WPU particles show a core-shell structure, in which HDI biuret is encapsulated by hydrophilic acrylic resin. 2K-WPU emulsion with HDI biuret has larger particle size and narrower distribution index, while for 2K-WPU emulsion with HDI isocyanurate, the latex not only has large particle size, but also has two-peak distribution. FTIR shows that the reaction between HDI biuret and acrylic resin can complete in 12h. In addition, studies on effect of composition of acrylic resin on performance of 2K-WPU show that narrowing the polar difference between water-soluble acrylic resin and HDI biuret and improving the miscibility of two components are the key to prepare the transparent and high gloss films with high crosslinking density.     

Optimal preparation and characterization of poly(urea–formaldehyde) microcapsules

Microcapsules with epoxy curing agent were successfully prepared by an in‐situ polymerization route with epoxy resin and poly‐(urea–formaldehyde) as core and shell materials, respectively. The synthetic conditions were optimized by a comprehensive investigation on raw materials consumption, size distribution, and surface morphology. Preparation of microcapsules with high wrap ratio was also demonstrated. The as‐synthesized microcapsules were studied using various characterizations techniques, including optical microscope, fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and contact angle meter. Spherical microcapsules (size: ～ 60 μm) with smooth surface were obtained when the stirring rate was 400 rpm and the amount of core materials is 76 wt %. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010