水性聚氨酯-丙烯酸酯复合乳液的性能研究

用丙烯酸酯改性水性聚氨酯制备了具有核壳结构的水性聚氨酯-丙烯酸酯(WPUA)复合乳液,系统地研究了水性聚氨酯(PU)含量、nNCO/nOH(初始物质的量比)、亲水性扩链剂二羟甲基丙酸(DMPA)用量及软硬单体质量比对WPUA乳液及其膜的性能的影响.结果显示,WPUA乳液胶粒呈核壳型结构,聚丙烯酸酯(PA)与PU链段具有...     

聚氨酯/聚丙烯酸酯复合乳液研究进展

综述了水性聚氨酯/聚丙烯酸酯(PUA)复合乳液几种合成方法:物理共混法,化学交联法,原位乳液聚合法,种子乳液聚合法以及微乳液和细乳液聚合法的研究进展,介绍了PUA复合乳液乳胶粒的不同核/壳结构和PUA互穿网络,报导了采用蓖麻油、有机氟、有机硅和环氧树脂改性PUA的技术进展以及新型光固化PUA,并对聚氨酯/聚丙烯酸酯乳液的发展方向作出了预测。     

硅溶胶/聚丙烯酸酯复合乳液的结构和性能研究

采用普通乳液聚合的方法,制备了硅溶胶/聚丙烯酸酯复合乳液.通过透射电镜(TEM)、傅里叶红外光谱仪(FT-IR)和动态激光散射仪(DLS)等对复合乳液中乳胶粒子的结构进行表征,并对复合乳液的涂膜性能进行研究.结果表明,所制备的复合乳液粒子具有核-壳结构,其中核是纳米级的SiO2粒子,壳是聚丙烯酸酯.性能测试结果表明,核-壳结构的存在使得复合乳液的涂膜在硬度、附着力和化学稳定性等方面均优于纯丙乳液及硅溶胶/聚丙烯酸酯的共混乳液.     

核-壳结构聚丙烯酸酯-聚氨酯微乳液性能

采用无皂乳液聚合方法制备出了具有核-壳结构的交联及非交联的聚丙烯酸酯-聚氨酯(PAC-PU)微乳液,讨论了核壳比、二元醇分子质量及其结构、异氰酸酯种类和交联剂用量对微乳液性能的影响,制得的所有 PAC-PU 微乳液(核壳比小于70/30)都具有较好的涂料性能。     

核壳型水性聚氨酯-聚丙烯酸酯复合乳液的制备及其影响因素

用丙烯酸酯改性水性聚氨酯(PU)制备了具有核壳结构的PU-聚丙烯酸酯(PA)复合乳液,对其结构进行了表征,研究了亲水性扩链荆二羟甲基丙酸(DMPA)用量、NCO/OH(摩尔比)、乳化剂用量、核壳质量比对乳液和涂膜性能的影响.结果表明,所制备的乳液为核壳型PU-PA复合乳液;当DMPA的质量分数为5.5%-6.0%、NCO-OH总摩尔比为1.3-1.4、NCO/OH初始摩尔比为4.5-5.5、乳化荆质量分数为1.0%、核壳质量比为30/70时,可得到性能较佳的PU-PA复合乳液和涂膜.     

水性聚氨酯树脂的改性技术

阐述了近年来国内外用于水性聚氯酯树脂的交联改性、丙烯酸酯改性与互穿网络改性等相关改性的厅法、理论、聚合工艺及改性后水性聚氨酯树脂的应用等。并指出在使用内交联法制备水性聚氨酯时，采用特殊的分子结构设计，可以获得较高交联密度的水性聚氨酯；采用外交联法制备的双组分水性聚氨酯，具有优良的机械性能、耐溶剂性、耐候性、低温成膜性等性能；在丙烯酸酯改性水性聚氨酯的研究中，采用顺序的方法可合成出同时含有聚氨酯和聚丙烯酸酯的具有核壳结构的复合乳胶粒。     

交联型聚硅氧烷/聚丙烯酸酯复合乳液的制备

在甲基丙烯酰氧丙基三甲氧基硅烷存在下，以交联的聚硅氧烷为种子，丙烯酸酯单体为第二单体，偶氮二异丁腈为引发剂，分别采用间歇法、溶胀法和半连续法制备了聚硅氧烷／聚丙烯酸酯复合乳液。采用透射电子显微镜对乳胶粒子形态进行了表征，发现乳液中形成了以聚丙烯酸酯为核、聚硅氧烷为壳的反相核壳结构乳胶粒子；放置90天后，乳胶粒子的形态未发生翻转；将复合乳液破乳后分析，聚合物凝胶量达到96％以上，说明聚合体系交联很好。     

辐射聚合制备核壳交联型的氟改性聚氨酯/丙烯酸酯复合乳液

将三羟甲基丙烷单烯丙基醚(TMPME)作为扩链剂引入到聚氨酯分子主链中合成出水性聚氨酯乳液,之后将其与含氟的甲基丙烯酸六氟丁酯(HFBMA)物理共混形成核壳型的聚氨酯/丙烯酸酯(PUA)复合乳液,通过~(60)Co射线引发核中HFBMA的双键与壳中聚氨酯TMPME侧链上的双键发生反应,从而使作为核的含氟丙烯酸酯和作为壳的聚氨酯产生核壳间的交联。与传统的PUA核壳乳液相比,此种核壳交联的乳液在成膜时,由于聚氨酯分子链和丙烯酸酯分子链之间存在化学键的连接,增强了聚丙烯酸酯和聚氨酯分子水平上的相容性,因此PUA涂膜的硬度、力学性能和耐候性得到大幅提高。而氟的引入使得PUA涂膜具有良好的耐水解性和耐化学品性。     

水性PUA消光织物涂饰剂的制备及性能研究

本研究采用乳液共聚技术,制备出具有核壳有限相容结构的水性聚氨酯-聚丙烯酸酯(PUA)乳胶粒子。利用纳米二氧化硅粉体进行原位改性,同时配合新型气相消光技术,在有效降低传统二氧化硅消光粉体用量的情况下得到消光性能优良的水性PUA消光织物涂层剂。通过红外光谱、激光动态光散射、应力应变测试等表征手段研究了所制备的PUA乳液的稳定性和成膜物性能,应用研究结果表明,使用协同消光技术制备的织物涂层,其光泽、粘色牢度、手感、重涂光泽稳定性等主要指标性能优异。     

酮肼交联水性聚氨酯/聚丙烯酸酯复合树脂的结构和性能研究

采用乳液聚合工艺,通过加入双丙酮丙烯酰胺(DAAM),合成了具有活性酮羰基的聚丙烯酸酯乳液;同时通过羟基酮将酮羰基引入聚氨酯分子中,经分散得到含活性酮羰基的聚氨酯树脂;将二者混合,并加入己二酰肼(ADH),得到酮肼交联水性聚氨酯/聚丙烯酸酯(PUA)复合树脂。通过红外光谱、动态力学分析和耐磨性等测定对涂膜结构和性能进行了表征和分析,并将其与常规水性聚氨酯/聚丙烯酸酯树脂等进行了比较。结果显示,酮肼交联的水性聚氨酯/聚丙烯酸酯树脂具有较好的性能。     

Preparation and properties of reactive polyurethane polyacrylate blends based on carbonyl‐hydrazide reaction

A new reactive polyurethane/polyacrylate (PU/PA) blend was developed by mixing a core–shell polyacrylate latex containing keto groups in shell layer and a polyurethane dispersion incorporating multiple hydrazide groups which was synthesized by introducing the poly‐hydrazide groups into the end of the vinyl‐terminated polyurethane chains. Fourier transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC) results indicated that poly‐hydrazide groups had been incorporated in the polyurethane chains. Transmission electron microscopy (TEM) micrograph revealed that polyacrylate particles had a clear core–shell structure. The results of FTIR, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) indicated that the crosslinking reaction between two polymer systems had happened and crosslinking structure could effectively improve the compatibility between PA and PU. Thermogravimetric analysis (TGA) and mechanical tests results suggested that crosslinking structure could enhance the thermal stability and mechanical properties of blends. The influence of the PA content and the n(? CO? )/n(? NHNH₂) ratio on the hardness, water resistance, solvent resistance, and gel fraction of the blend films were comprehensively studied. The optimal PA content and n(? CO? )/n(? NHNH₂) ratio was 30% and 1.5:1 in this experiment, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44443.     

Investigation of fluorinated polyacrylate latex with core–shell structure

Fluorinated polyacrylate latices with core–shell structure were prepared by semi‐continuous emulsion polymerization, using a mixed emulsifier system composed of a reactive emulsifier and a small amount of anionic emulsifier. The conversion and chemical components of the final latices were studied by gravimetric methods and Fourier‐transform infrared (FTIR) spectrometry, respectively. The structure of the latex particles was determined by differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and particle size analysis. The latex films exhibited a low surface energy and high water‐contact angles. The surface analysis from X‐ray photoelectron spectroscopy (XPS) revealed that the fluorinated components preferentially self‐organized at the film–air interface. From XPS depth profiling of the film, it was found that a gradient concentration of fluorine existed in the structure of the latex film from the film–air interface to the film–glass interface. Compared with the core–shell structure with a fluorinated core, the core–shell structure with a fluorinated shell was more effective for modifying the properties of the latex films. Copyright © 2005 Society of Chemical Industry     

Structure and property characterization of nanograde core‐shell polyurethane/polyacrylate composite emulsion

Anionic aqueous polyurethane dispersion was synthesized through self‐emulsifing method from cycloaliphatic isophorone diisocyanate (IPDI) and dimethylolpropionic acid (DMPA). The carboxyl acid group in DMPA was used to make the polyurethane dispersible. The polyurethane/polyacrylate (PU/PA) composite particles were also prepared by seeded surfactant‐free emulsion polymerization; the cycloaliphatic polyurethane aqueous dispersion was used as seed particles. The structures and properties of the composite emulsion as well as the physical mixture of polyurethane dispersion and polyacrylate emulsion were characterized by FTIR, DSC, dynamic light scattering, TEM, X‐ray photoelectron spectroscopy (ESCA), and electronic tensile machine. The results showed that the synthesized PU/PA composite emulsion was found to form inverted core‐shell structure with polyacrylate as the core and with polyurethane as the shell, and its diameter of particles is in the range of nanograde, the crosslinking reaction was existed in composite emulsion. The intimate molecular mixing of crosslinking polymers are also claims to result in a superior balance of properties compared to physical blends of polyurethane dispersion and acrylate emulsion. The crosslinking mechanism of PU/PA composite emulsion was also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Facile preparation of homogenous waterborne poly(urethane/acrylate) composites and the correlation between microstructure and improved properties

Homogenous waterborne polyurethane/polyacrylate emulsions were synthesized based on the prepared polyurethane and polyacrylate through a facile process. The attention was attracted to the miscibility and performance of waterborne polyurethane and polyacrylate. The structures and properties of waterborne polyurethane and waterborne polyurethane/polyacrylate samples were characterized by using Fourier transform infrared spectroscopy, transmission electron microscope, X-ray photoelectron spectroscopy, X-ray diffractometer, thermogravimetric, and so forth, as well as solid content and tensile testing. The results showed that the micro morphology of waterborne polyurethane/polyacrylate emulsion presented single-phase structure with the stoichiometric polyacrylate content increasing from 33% to 80% to waterborne polyurethane. The waterborne polyurethane/polyacrylate films surface is rich in polyacrylate phase. Meanwhile, waterborne polyurethane/polyacrylate composites showed significant improvement in thermal stability and elongation at break, smaller particle size and narrower particle size distribution comparing with waterborne polyurethane.     

Synthesis of ambient temperature self-crosslinking VTES-based core–shell polyacrylate emulsion via modified micro-emulsion polymerization process

Modified micro-emulsion polymerization was successfully used to synthesize a kind of ambient temperature self-crosslinking core–shell emulsion, consisting of polyacrylate core and vinyltriethoxysilane (VTES) modified polyacrylate shell, by varying the ratio of soft monomer (BA) and hard monomer (MMA) which is different in the core and shell. The emulsion and its film formed at ambient temperature were characterized by attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Core–shell structure was clearly shown in TEM micrographs, and two distinct glass transition temperatures (T _g) were confirmed by DSC analysis. Lower T _g of core phase analyzed by DSC and self-crosslinking properties of VTES characterized by crosslinking degree cause latex particles form continuous film at ambient temperature. Thermal and mechanical properties and the surface properties of the latex films were also investigated. Results showed that the core–shell latex films containing 5 and 7.5 % VTES exhibited higher thermal stability, better mechanical properties, higher contact angle, and water resistance compared with pure polyacrylate film.     

Fabrication and properties of chemically bonded polysilsesquioxane‐polyacrylate/silica hybrid latex films with high silicon content

Polysilsesquioxane‐polyacrylate/silica hybrid latexes (PSQ‐PAS) with high silicon content were prepared by directly mixing colloidal silica with polysilsesquioxane‐polyacrylate emulsion (PSQ‐PA), which was prepared through seeded emulsion polymerization using polymethacryloxypropylsilsesquioxanes as the core and polyacrylate (PA) as the shell respectively. The chemically bonded PSQ‐PAS thin films were obtained via sol‐gel process after addition of hydrophilic cosolvent to PSQ‐PAS emulsion and subsequent drying at room temperature. The effects of silica/PSQ‐PA ratio (w/w) on the film properties of hardness, optical property and thermal stability were investigated. Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to characterize the chemical composition and morphology of the resultant hybrid particles. DLS and TEM results indicated that both PSQ and PSQ‐PA particles had narrow size distribution and their average diameters were about 200 and 350 nm, respectively. Pendulum durometer, UV–vis spectroscopy, and thermogravimetric analysis (TGA) were used to characterize the hardness, optical property and thermal stability of PSQ‐PAS latex films. The results showed that the PSQ‐PAS films hardness increased with the increasing ratio of silica/PSQ‐PA, whereas the transmittance decreased slightly. TGA curves demonstrated PSQ‐PAS films displayed excellent thermal stability, and the residual silicon weight exceeded 30%. POLYM. COMPOS., 36:389–396, 2015. © 2014 Society of Plastics Engineers     

Preparation and swelling behavior of moisture‐absorbing polyurethane films impregnated with superabsorbent sodium polyacrylate particles

Moisture‐absorbing composite films were prepared with superabsorbent sodium polyacrylate particles and solvent‐type polyurethane for applications in fabrics. To study the effect of the particle size of sodium polyacrylates on the swelling capacity and deswelling behavior of the composite films, we prepared sodium polyacrylates with different particle sizes ranging from 277 μm to 485 nm. The rate of absorption and the swelling capacity of the composite films were generally observed to increase with decreasing sodium polyacrylate particle size—except that the water absorbency of the composite film containing the very smallest, 485‐nm‐size, sodium polyacrylate particles was lower than that yielded by the larger particles, perhaps because these very small sodium polyacrylate particles were impregnated inside the polyurethane matrix rather than on the surface. Meanwhile, the deswelling behavior was not significantly affected by the particle size. Differences in the ionic solutions also significantly affected the swelling capacity of the composite film and altered its swelling kinetics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43973.     

界面聚合聚脲/聚氨酯复合壳体香精微胶囊的制备及性能

以茉莉香精为芯材,以异氟尔酮二异氰酸酯（IPDI）分别与二乙烯三胺（DETA）、β-环糊精（β-CD）及β-CD/DETA反应物为壁材,采用界面聚合法制备了聚脲、聚氨酯、聚脲/聚氨酯3种不同结构壳体的香精微胶囊。探究了不同微胶囊壳体对微胶囊表观形貌、热稳定性、香精微胶囊缓释性的影响并通过动力学模型分析了香精扩散方式。结果表明,以β-CD/DETA制备的聚脲/聚氨酯复合壳体微胶囊成囊性优异,壳体致密完整,热稳定性和缓释性能最好,经其整理的纺织品可保持较浓香味90多天。3种香精微胶囊在100℃、120℃高温缓释数据均符合零级、一级、Ritger-Peppas及Higuchi动力学模型。聚脲/聚氨酯复合壳体Ritger-Peppas方程拟合后n值更加接近0.45,更符合Fick扩散,缓释性能更好。     

Synthesis and characterization of poly(butyl acrylate–methyl methacrylate)/polyaniline core–shell latexes

Poly(butyl acrylate–methyl methacrylate) [P(BA–MMA]/polyaniline (PANI) core–shell complex particles were synthesized with a two‐step emulsion polymerization method with P(BA–MMA) as the core and PANI as the shell. The first step was to prepare P(BA–MMA) latex particles as the core via soapless emulsion polymerization. The second step was to prepare P(BA–MMA)/PANI core–shell particles. Sodium dodecyl sulfate was fed into the P(BA–MMA) emulsion as a surfactant, and this was followed by the addition of the aniline monomer. A bilayer structure of the surfactant over the surfaces of the core particles was desired so that the aniline monomer could be attracted near the outer surface of the core particles. In some cases, dodecyl benzene sulfonic acid was added after 2 h when the polymerization of aniline was started. The final product was the desired core–shell particles. The morphology of P(BA–MMA) and P(BA–MMA)/PANI particles was observed with transmission electron microscopy. The thermal properties were studied with thermogravimetric analysis and differential scanning calorimetry. Furthermore, conductive films made from the core–shell latexes were prepared, and the electrical conductivities of the films were studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 823–830, 2007     

Chemical components and properties of core–shell acrylate latex containing fluorine in the shell and their films

Core–shell acrylate latices containing fluorine in the shell were prepared by semicontinuous emulsion polymerization. The chemical components of the latices were determined by Fourier transform infrared, ion‐selective electrode analysis, and differential scanning calorimetry. The average size and morphology of the latex particles were characterized by photocorrelation spectroscopy and transmission electron microscopy, respectively. The latex particles were mainly composed of a non‐fluorine core and a fluorinated shell. The dynamic water contact angles of the latex films from the Wilhelmy method indicated that the latex films containing fluorine in the shell could be wetted by water only with difficulty. The amount of the fluoromonomer played an important role in the modification on the water contact angles, water absorption, and thermal stability of the latex films. In comparison with a random structure, the core–shell structure was more effective for improving the thermal properties of the latex films. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 107–114, 2006