聚氨酯-丙烯酸酯复合乳液成功合成

聚氨酯-丙烯酸酯复合乳液虽然较单一乳液的性能有很大改善,但是其涂膜的硬度、耐水性、耐化学品性还难以满足高档水性木器涂料的要求。最近,湖南大学化学化工学院在聚氨酯-丙烯酸酯复合乳液中,以不同方式加入环氧树脂,分别制备了物理共混和化学共聚的聚氨酯-丙烯酸酯-环氧树脂复合乳液（PUEA）,着重研究了环氧树脂加入方式、用量等对乳液及涂膜性能的影响。发现环氧树脂对于涂膜的硬度、耐水性、耐化学品性等有明显改进．研究还表明,环氧树脂的质量分数在3％～4％为宜。近年许多研究者利用PU乳液和PA乳液性能上具有的良好互补作用,共聚制备聚氨酯-丙烯酸酯（PUA）复合乳液;在先前的PUA复合乳液研究基础上,加入环氧树脂,合成环氧树脂改性的聚氨酯-丙烯酸酯（PUEA）复合乳液,可使其涂膜的吸水率显著降低,硬度与其他有关性能也有一定提高。     

多重交联聚氨酯-丙烯酸酯复合乳液的合成研究

采用种子乳液聚合结合原位乳液聚合法,引入分子间和分子内交联的交联结构,制备了多重交联的聚氨酯-丙烯酸酯复合乳液,研究了交联基团加入方式、用量等对乳液及涂膜性能的影响.研究发现交联度的提高对于涂膜的硬度、耐水性、耐化学品性等有明显改进.     

自交联型聚氨酯-丙烯酸酯复合乳液的合成研究

采用原位乳液聚合法,引入分子间交联的交联结构,制备了酮肼、环氧羧基双重自交联型聚氨酯-丙烯酸酯复合乳液,研究了交联基团对乳液及涂膜性能的影响。研究发现交联度的提高对于涂膜的硬度、耐水性、耐化学品性等有明显改进。     

聚氨酯/丙烯酸酯复合乳液

<正>近年来,许多研究者利用聚氨酯(PU)乳液和丙烯酸酯(PA)乳液共聚具有性能互补的作用,制备了聚氨酯/丙烯酸酯(PUA)复合乳液。虽然,PUA复合乳液较单一乳液性能好,但是其涂膜的硬度、耐水性和耐化学品性还难以满足高档水性木器涂料的要求。     

环氧树脂改性聚氨酯乳液的研究进展

综述了环氧树脂相互改性聚氨酯乳液的研究进展。环氧树脂改性聚氨酯乳液的方法包括物理共混法和化学共聚,改性后乳液的固含量提高、涂膜的硬度和拉伸强度增加、耐水性耐化学品性增强。     

防腐涂料用环氧改性聚氨酯-丙烯酸酯乳液的合成

以环氧树脂开环制备的环氧树脂多元醇为改性剂,与甲苯二异氰酸酯(TDI)、聚醚二元醇(GE220)、二羟甲基丙酸(DMPA)和甲基丙烯酸甲酯(MMA)等原料合成环氧树脂改性聚氨酯-丙烯酸酯(PUEA)复合乳液,并应用于金属表面防腐.研究发现:环氧树脂多元醇、DMPA和MMA的用量等因素对乳液及涂膜性能的影响显著.当DMPA、环氧树脂多元醇和MMA的质量分数分别为7％～7.5％、12％和25％ ～35％时,涂膜的耐水性、硬度和耐盐雾性最佳.     

新型聚氨酯-聚丙烯酸酯水性体系的热固化与UV固化研究

利用多官能度的三羟甲基丙烷三丙烯酸酯(TMPTA)制备了一种新型的聚氨酯-丙烯酸酯(PUA)复合乳液,分别对所得乳液及相应涂膜进行热固化和UV同化.利用FT-IR光谱对PUA的结构进行了表征,考察了PUA复合乳液的乳液性能;对两种固化体系的双键转化率进行了研究;同时对两种固化方式所得到的涂膜性能进行了研究和比较.实验结果发现,固化后涂膜的力学性能、耐水性、耐溶剂性和耐化学品性均得到显著提高.通过比较发现,UV固化体系涂膜的综合性能优于热固化体系.     

聚氨酯-环氧树脂复合乳液研究进展

综述了聚氨酯和环氧树脂相互改性乳液的研究进展。聚氨酯改性环氧树脂乳液的方法包括物理共混法、化学共聚的单组分法与双组分法以及聚氨酯固化剂改性法,改性乳液涂膜的力学性能和柔韧性明显提高。环氧树脂改性聚氨酯乳液的方法包括物理共混法和化学共聚的直接改性法、间接改性法,改性乳液的固含量提高,涂膜的硬度、耐水性、耐化学品性增强。     

高硬度磺酸型水性聚氨酯涂料的合成及性能研究

采用γ-氨丙基三乙氧基硅烷(KH-550)和环氧树脂(E-44)复合改性磺酸型水性聚氨酯,制得硬度高、耐热性和耐化学品性能优异的水性聚氨酯涂料。通过衰减全反射红外分析了聚氨酯的结构,用DSC、TG等对涂膜进行了表征。考察了KH-550及E-44含量对涂膜硬度、耐化学品性及耐热性的影响,结果表明:KH-550和E-44的加入均明显改善了涂膜的硬度和耐化学品性,当KH-550含量为6%~8%,E-44含量8%~10%时,涂膜的综合性能最优。     

建筑涂料用水性聚氨酯乳液的改性研究北大核心

以异佛尔酮二异氰酸酯、聚丙二醇、二羟甲基丙酸、1,4-丁二醇、乙二胺和环氧树脂为原料,制备了涂料用环氧树脂改性水性聚氨酯乳液,并研究了环氧树脂的加料顺序和加入量对乳液外观以及涂膜耐水性、力学性能的影响。结果表明:选择先改性后中和的加料顺序制备了固含量较高且稳定性较好的改性水性聚氨酯乳液;环氧树脂质量分数为6%时,改性水性聚氨酯乳液的外观及稳定性最好,涂膜的耐水性、硬度、拉伸性能等较优异,可用作建筑涂料。     

Crosslinked polyurethane–epoxy hybrid emulsion with core–shell structure

An epoxy resin was used to prepare crosslinked polyurethane hybrid emulsion through the blocked NCO prepolymer mixing process. Due to their hydrophobicity, the amine chain extender, blocked –NCO, and epoxy are located inside the emulsion particles. Thus, the crosslinking reaction occurs mostly in the interior of the particles. In this way, the crosslinking density of the resin is increased without the use of solidifying agents or heating during film formation, and the stability of the emulsions remains uninfluenced. The effects of the type of amine chain extender and the type, dosage, and addition mode of the epoxy resin were studied in terms of mechanical properties and swelling properties in water and toluene of the cast films. Additionally, the stability of the single-pack hybrid emulsion was studied. The results showed that the sample prepared with diethylene triamine had good stability, chemical resistance, and high mechanical strength. The modulus and water resistance of the films increased with the epoxy resin content, which could reach 20 wt%. The type of amine chain extender affected the stability of the emulsions significantly. The molar ratio of NH/NCO at 1:1 led to the best film performance. The optimal temperature of the chain-extension reaction was approximately 80°C. The hybrid emulsions could be stored for at least 6 months without apparent performance changes.     

环氧树脂改性水性聚氨酯-丙烯酸酯的初步研究

合成了环氧树脂改性的水性聚氨酯 丙烯酸酯 ,研究了环氧树脂用量、加入方式对乳液稳定性的影响。环氧基团在乳液胶膜热处理时交联 ,从而改善了胶膜的力学性能及耐水性、耐溶剂性能。     

Syntheses and properties of cationic amine–epoxy adducts and their use in electrodeposition: I. Diethanolamine/diethylamine terminated cationic epoxy with pendant 2-ethylhexanol-blocked TDI groups

Alkyl partially blocked toluene diisocyanate (PBTDI) and hydroxyl group-containing polyepoxide were mixed to produce a blocked TDI–epoxy resin and then reacted with secondary amine and treated with acetic acid to give a cationic resin. In this study, six cationic resins (IV-A and IV-B, two series) were synthesized from three diglycidyl ethers of bisphenol A with different epoxy equivalent weights of 508, 650, and 950, and two secondary amines (diethylamine and diethanolamine). Acetic acid was used as the neutralization agent and ethylene glycol mono-n-butyl ether (butyl cellosolve, BCS) and deionized water were utilized as the emulsion solvents. Some properties of electrodeposition, such as throwing power and rupture voltage, and some physical and chemical properties of the deposited films were investigated. It was found that the appearance of emulsion, deposition yields, and quality of the deposited films are strongly dependent on pH, BCS, and resin contents. To obtain suitable deposition properties and stable emulsions from IV-A and IV-B systems, the aqueous dispersion should meet the following conditions: pH, 5.5-6.0; BCS contents, 3.0–5.0 wt %; and resin concentration, 7.0–9.0 wt %. For both systems, the deposited films had good appearance, adhesion, hardness, and alkali reagent resistance. The salt spray resistance and acid resistance of films deposited from series III-A (epoxy resin formulations containing diethylamine) are superior to films deposited from series III-B (epoxy resin formulations containing diethanolamine).     

水性聚氨酯/硅溶胶复合涂层的制备与性能

将水性聚氨酯乳液与硅溶胶共混,制备了水性聚氨酯/硅溶胶复合乳液。采用TEM、激光粒度分析仪、流变仪、ATR-FTIR、TG对复合乳液及其涂膜进行表征,探讨了硅溶胶用量对复合涂膜性能的影响。ATR-FTIR分析表明,聚氨酯分子和硅溶胶之间可以形成氢键,但不存在化学键结合;TEM、激光粒度分析测试表明,硅溶胶质量分数的增加,使复合乳液粒子粒径增大,粒度分布变宽,当硅溶胶质量分数20%后,乳胶粒子间易发生团聚;流变分析发现,加入硅溶胶后,乳液的表观黏度(ηa)增大,假塑性增强。性能测试结果表明,硅溶胶质量分数20%时,复合乳液具有好的储存稳定性,复合涂膜表现出很好的热稳定性,48 h吸水率仅为18.94%,同时表现出很好的耐溶剂性能,拉伸强度达到28.98 MPa,铅笔硬度达2H,附着力0级。     

水性聚氨酯/聚甲基丙烯酸甲酯杂化乳液的合成

用异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG)和二羟甲丙酸(DMPA)合成了水性聚氨酯分散体(WPU),讨论了PPG摩尔质量,NCO/OH及PPG/DMPA比例对WPU乳液和涂膜性能的影响。以WPU为种子与甲基丙烯酸甲酯进行乳液聚合制备杂化乳液,研究了不同PU/PMMA物质的量比例对杂化乳液及涂膜性能的影响,并采用TEM对WPU及杂化乳液粒子进行了表征。结果表明,在以PPG1000为原料,NCO与OH物质的量比为1.4∶1,PPG与DMPA物质的量比为1∶0.8条件下制备的WPU杂化乳液,随着PMMA比例增加,杂化乳液的稳定性和成膜性变差,聚合物膜断裂伸长率降低,但铅笔硬度、耐水性及耐乙醇性均得到了改善。     

Preparation and properties of poly(siloxane‐ether‐urethane)‐acrylic hybrid emulsions

Poly(siloxane‐ether‐urethane)‐acrylic (PU‐AC) hybrid emulsions were prepared by introducing different hydroxyethoxypropyl‐terminated polydimethylsiloxane (PDMS) content into the acrylic‐terminated poly(ether‐urethane) backbone and then in situ copolymerizing with methyl methacrylate and butyl acrylate via emulsion process. The effects of PDMS on the particle size and viscoelastic behavior of the hybrid emulsions were investigated. Meanwhile, the hydrogen bonding, mechanical and thermal mechanical properties, water resistance, the surface gloss, and wettability of the resultant hybrid films were also studied. The results showed that all the hybrid emulsions showed shear‐thinning behaviors, and the introduction of PDMS resulted in the formation of the hybrid emulsions with increased average particle size and decreased viscosity. The chemical bonds built between PU and AC yielded higher than 73% crosslinking fraction in all the hybrid materials, but this value decreased with increasing PDMS content because PDMS reduced the hydrogen bonding interactions and enhanced the phase separation. As a result, an increase in the PDMS content led to an increase in the elongation, water resistance, surface roughness, and water hydrophobic of the films, but the tensile strength, hardness, storage modulus, and glass transitions temperature decreased. It is suggested that introduction of PDMS can provide the hybrid materials with the improved flexibility, water resistance, and surface hydrophobicity, which has potential application value in the fouling‐release coatings, biomaterials, and surface fishing. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44927.     

An epoxy novolac emulsion system for ambient cure protective coatings

Conclusions  Water-borne two-pack coatings based on a novel low particle size epoxy novolac emulsion, crosslinked with polycycloaliphatic polyamine provide a good balance of several properties. Because the films cured possess a high crosslink density of cross linkage, expectations such as rapid through film drying time, high hardness development at an early stage during cure, very good film formation at 10°C and 80% R.H., and chemical resistance can be met. However, there are also adverse aspects to consider regarding the combination of a water-insoluble hydrophobic polyamine and a modified epoxy novolac emulsion. eg no visible end of pot life, relative short pot life and a brittleness of coatings associated with a tendency to peeling when exposed to salt spray and humid conditions. The study also revealed that the quality of a cured two-component epoxy binder emulsion system depends to a great extent on the quality of the emulsion, particularly on the size and distribution of the droplets. A low particle size epoxy emulsion improves the film formation, drying time, water resistance, gloss, adhesion and hardness. For this purpose epoxy emulsions with a narrow particle size distribution and relatively low particle size (mean value ca. 0.4 μm) can be developed using a proprietary mechanical emulsion process. The aqueous coating system described may be useful for applications where conventional epoxy novolacs are already used as low temperature heat cure coatings like drill pipe coatings, oil pipelines and fuel storage tanks and in fields where their chemical, water and solvent resistance can be utilised. Further ambient cure applications may be protective coatings for indoor use, eg food factories, schools, hospitals and office buildings, industrial maintenance coatings for concrete, mortar, bricks, plaster and wood.     

水性聚氨酯丙烯酸酯的多重交联改性及其相转变

以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(N220)、甲基丙烯酸甲酯(MMA)为主要原料合成了脂肪族聚氨酯-丙烯酸酯复合乳液,并采用蓖麻油、环氧树脂和三羟甲基丙烷对其进行改性。通过综合性能测试研究了各种交联剂添加量对乳液及其涂膜性能的影响。并通过粘度和电导率测试研究了聚氨酯剪切乳化过程的相转变及各交联剂对相转变的影响。结果表明:当蓖麻油、环氧树脂和TMP的添加量分别为7%、3%、3%时,可得到稳定、耐水耐介质性好、硬度较高、力学性能突出的聚氨酯丙烯酸酯复合乳液;各交联剂都会使相变点后移,尤其以环氧树脂的影响最为明显。     

Polyurethane‐acrylic hybrid emulsions with high acrylic/polyurethane ratios: Synthesis,characterization, and properties

Allyl polyoxyethylene ether (APEE) was used as coupling agent between polyurethane (PU) and acrylic polymer (AC) to synthesize stable waterborne polyurethane‐acrylic (PU‐AC) hybrid emulsions with high AC/PU weight ratio ranged from 45/55 to 70/30. The effect of the AC/PU weight ratio and the acrylate type including methyl methacrylate (MMA), butyl acrylate (BA) and mixture of them on the properties of the synthesized emulsions and resultant films were investigated. The research results showed that the colloidal particle of the emulsions behaved core‐shell structure, and the copolymers were not crosslinked. An increase in the AC/PU weight ratio led to an increase in the average particles size and the particle size distribution, but decrease in the viscosity of the emulsions. Meanwhile, the molecular weight distribution of the copolymers became wide, and the tensile stress, shore A hardness, storage modulus, glass transfer temperature, water resistance, and water contact angle of the resultant films increased, except that the films of PU‐BA were too soft to determine their mechanical properties. MMA and BA can provide the PU‐AC hybrid emulsions with very different properties, and which can be adjusted according to the special application. It was suggested that APEE can not only built up chemical bonds between PU and AC, but also increase the self‐emulsifying ability in the emulsion polymerization due to its hydrophilic ethylene oxide and carboxylic groups, resulting in that PU‐AC hybrid emulsions with high AC/PU ratio can be obtained by this method. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44488.     

水性聚氨酯的改性研究

分别采用丙烯酸酯、环氧树脂合成2种不同的改性水性聚氨酯,比较了改性前后及2种不同的改性水性聚氨酯在乳液、涂膜性能及粘接性能方面的差异。结果表明,改性后的水性聚氨酯综合性能明显提高,其中环氧树脂改性水性聚氨酯(EPU)在固化交联后涂膜的耐水、耐溶剂及力学性能又明显好于丙烯酸酯改性水性聚氨酯(PUA),其粘接强度与溶剂型聚氨酯相当;而采用丙烯酸酯改性的水性聚氨酯PUA乳液稳定性好于EPU乳液。