含氟硅丙烯酸酯核壳乳液及涂膜表面性能

在可聚合阴离子乳化剂体系下,以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主要单体,甲基丙烯酸十二氟庚酯(DFMA)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)为功能单体,采用半连续种子乳液聚合法合成了含氟硅丙烯酸酯核壳乳液。考察了DFMA和KH-570用量对乳液聚合过程和乳胶膜表面疏水性能的影响,并对乳胶膜的表面自由能进行了估算。采用傅里叶红外光谱(FT-IR)、差示扫描量热仪(DSC)、热重(TG)、接触角(CA)及X射线光电子能谱(XPS)对氟硅丙乳液及乳胶膜进行了表征。研究结果表明,氟硅单体有效地参与了聚合,乳胶膜中氟硅元素呈梯度分布,当氟硅丙乳液中DFMA和KH-570用量分别为16%和5%（质量分数）时,涂膜-空气界面与去离子水的接触角为110.6°,涂膜的表面能低至15.4 mN·m^-1,其疏水性和耐热性有较大幅度提高。     

Preparation and surface properties of core‐shell polyacrylate latex containing fluorine and silicon in the shell

The core‐shell polyacrylate latex particles containing fluorine and silicon in the shell were successfully synthesized by a seed emulsion polymerization, using methyl methacrylate (MMA) and butyl acrylate (BA) as main monomers, dodecafluoroheptyl methacrylate (DFMA), and γ‐(methacryloxy) propyltrimethoxy silane (KH‐570) as functional monomers. The influence of the amount of fluorine and silicon monomers on the emulsion polymerization process and the surface properties of the latex films were discussed, and the surface free energy of latex films were estimated using two different theoretical models. The emulsion and its films were characterized by particle size distribution (PSD) analysis, transmission electron microscopy (TEM), Fourier transform infrared spectrum (FTIR), nuclear magnetic resonance (¹H‐NMR and ¹⁹F‐NMR) spectrometry, contact angle (CA) and X‐ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and thermogravimetry (TG) analysis. The results indicate that the average particle size of the latex particles is about 160 nm and the PSD is narrow, the synthesized latex particles exist with core‐shell structure, and a gradient distribution of fluorine and silicon exist in the latex films. In addition, both the hydrophobicity and thermal stability of the latex films are greatly improved because of the enrichment of fluorine and silicon at the film‐air interface, and the surface free energy is as low as 15.4 mN/m, which is comparable to that of polytetrafluoroethylene (PTFE). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Well-defined core-shell nanoparticles containing cyclodextrin in the shell: A comprehensive study

The purpose of this study was to conceive novel nanoparticles (NPs) designed for drug delivery applications. The NPs were based on a hydrophobic poly (lactic acid) (PLA) core and a hydrophilic β-cyclodextrin polymer (Poly-β-CD) shell. The PLA NPs were prepared by the nanoprecipitation method. The Poly-β-CD shell was obtained by adsorption from Poly-β-CD solution. Different complementary techniques have been used to fully characterize the system including dynamic light scattering, Zeta potential measurements, solution proton nuclear magnetic resonance spectroscopy, transmission electron microscopy, and small angle neutron scattering. They provide good evidence of a core-shell structure. The NPs parameters are dependent on the elaboration process, Poly-β-CD characteristics and adsorption conditions. In the conditions of adsorption’ saturation, the shells were constituted of Poly-β-CD monolayers covering the PLA surfaces with adsorption amounts from 2 to 4 mg/m², allowing reaching Poly-β-CD weight fractions of 10-20% in the NPs.     

壳层含硅的丙烯酸酯核壳乳液研究

以半连续滴加法制备壳层含γ-(甲基丙烯酰氧基 ) -丙基三甲氧基硅烷的丙烯酸酯核 -壳乳液。探讨了聚合条件对聚合反应的影响 ,并确定了最佳聚合条件。以红外光谱 (IR)、热分析仪 (TGA、DSC)、动态表面能分析仪、透射电子显微镜 (TEM)表征乳胶的性质及结构。     

Synthesis and characterization of polyacrylate latex containing fluorine and silicon via semi-continuous seeded emulsion polymerization

The polyacrylate latex containing fluorine and silicon were successfully synthesized by semi-continuous seeded emulsion polymerization in the presence of the mixed emulsifier of novel sodium lauroyl glutamate (SLG) anion surfactant and BCE-10 nonionic surfactant, which methyl methacrylate (MMA) and butyl acrylate (BA) were used as main monomers and hexafluorobutyl methacrylate (HFMA) and vinyltriethoxysilane (VTES) were used as the functional monomers. Potassium persulfate (KPS) was used as the initiator. The structural groups of the latex films were evaluated by Fourier transform infrared spectroscopy (FTIR). Thermal performance of the film was evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis. The latex particle size and its distribution were measured by the dynamic light scattering detector. Furthermore, surface hydrophobicity of the latex film was examined by measurement of water contact angle (WCA). WCA and thermal stability of the film are increased with the increased amount of HFMA and VTES. Factors, which have an influence on the properties of the resultant latex and its film, are investigated in detail. Results show that the optimal condition of synthesizing the emulsion is as follows: the amount of emulsifiers is 7.0%; mass ratio of SLG to BCE-10 is 1:1; the amount of initiator is 0.8%; the mass ratio of MMA to BA is 1:1; the content of the fluorine monomer and silicon monomer is 6.0%.     

Synthesis and properties of the vinyl silicone oil modified polyacrylate core-shell latex as a binder for pigment printing

Vinyl silicone oil (VSO) modified polyacrylate latex is synthesized by emulsion polymerization. The core-shell structure of the latex particle is observed on transmission electron microscopy. The chemical structure of the copolymer was characterized by infrared spectrum. The glass transition temperatures of core-layer and shell-layer of latex particle are determined by differential scanning calorimetry. The size of particle of the core-shell latex is measured on a nanoscale granularity analyzer. The good softening effect of VSO is proved by the application of the latex as a binder of pigment printing on textiles. The good fastness of the printed fabrics is obtained^, which shows that the synthesized core-shell latex can be used as a binder in pigment printing of textiles.     

氟代聚丙烯酸酯改性聚氨酯复合乳液的制备及其疏水性

为了提高聚氨酯-丙烯酸酯复合乳液的耐水性和耐溶剂性,将聚氨酯溶液作为反应介质,以丙烯酸十二氟庚酯(FA)和丙烯酸羟丙酯为单体,偶氮二异丁腈为引发剂,在溶液中进行聚丙烯酸酯自由基聚合,然后用N-甲基二乙醇胺进行亲水基扩链,通过溶液聚合相转化法制得新型阳离子氟代聚丙烯酸酯改性聚氨酯复合乳液。通过红外光谱、透射电镜、光电子能谱仪和接触角测定仪分别对复合乳液的结构、乳胶粒形态、膜表面的化学元素组成及疏水性进行了研究。结果表明,含氟链段成功接入了大分子链中,乳液形成稳定的核-壳结构,在膜材料表面形成了主要由含氟丙烯酸酯链段组成的界面,FA的引入可使复合乳液胶膜与水的接触角(PUA膜与水的接触角)由65°提高至98°。     

Morphological prediction and its application to the synthesis of polyacrylate/polysiloxane core/shell latex particles

A theoretical analysis and a morphological prediction of polyacrylate (PA)/polysiloxane (PSi) latex particles with core/shell morphologies were first conducted based on interfacial tensions and relative volumes of the two polymers in the latex system. The results indicated that the normal core/shell morphology particles (PSi/PA), with hydrophobic polysiloxane as the core and with hydrophilic polyacrylate as the shell, can be easily formed. Although the inverted core/shell morphology particles (PA/PSi) with polyacrylate as the core could not be formed in most cases, even if the fraction volume of polysiloxane was larger than 0.872, which is the smallest value of forming a PA/PSi particle, the PSi/PA particles were unavoidably formed simultaneously with PA/PSi particle formation. The synthesis of PA/PSi particles containing equal amounts of polyacrylate and polysiloxane was then carried out using seeded emulsion polymerization. Before the cyclosiloxane cationic polymerization, 3‐methacryloyloxypropyl trimethoxysilane (MATS) was introduced into the polyacrylate seed latex to form an intermediate layer and chemical bonds between the core and the shell polymers. The characterization by transmission electron microscopy (TEM) demonstrated that the perfect PA/PSi core/shell particle is successfully synthesized when both the core and the shell polymers are crosslinked. The experiments showed that both the hardness and water adsorption ratio characteristics of latex films of the PA/PSi particles are in good agreement with those of the polysiloxane film. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2251–2258, 2001     

Synthesis and properties of fluorine–silicon modified polyacrylate hybrid latex particles with core–shell structure obtained via emulsifier‐free emulsion polymerization

A core–shell fluorine–silicon modified polyacrylate hybrid latex was successfully prepared via emulsifier‐free emulsion polymerization. The chemical composition and core–shell morphology of the resultant hybrid particles were investigated using ¹H NMR and Fourier transform infrared spectroscopies and transmission electron microscopy (TEM), respectively. TEM analysis indicated that the core–shell hybrid particles were uniform with narrow size distributions. The particle size and zeta potential decreased with an increase of alkylvinylsulfonate surfactant from 2.5 to 6.0 wt%. X‐ray photoelectron spectroscopy revealed that fluorine concentrated preferentially at the film surface during a film‐formation process. The film formed from the fluorine–silicon modified polyacrylate showed much higher thermal stability than a film formed from polyacrylate and fluorine‐modified polyacrylate. Contact angle results showed that a finished fabric had remarkable water repellency. © 2015 Society of Chemical Industry     

核-壳结构含氟丙烯酸酯乳液的合成与表征

A fluorine-containing polyacrylate copolymer emulsion was synthesized by a seed emulsion polymerization method, in which methyl methacrylate （MMA） and butyl acrylate （BA） were used as main monomers and hexafluorobutyl methacrylate （HFMA） as fluorine-containing monomer. The structure and properties were characterized by Fourier transform infrared spectrum （FT-IR）, transmission electron microscopy （TEM）, particle size analysis, X-ray photoelectron spectroscopy （XPS）, contact angle （CA）, differential scanning calorimetry （DSC） and thermogravimetry （TG） analysis. The FTIR and TEM results showed that HFMA was effectively involved in the emulsion copolymerization, and the formed emulsion particles had a core-shell structure and a narrow particle size distribution. XPS and CA analysis revealed that a gradient concentration of fluorine existed in the depth profile of fluorine-containing emulsion film which was richer in fluorine and more hydrophobic in one side. DSC and TG analysis also showed that a clear core-shell structure existed in the fluorine-containing emulsion particles, and their film showed higher thermal stability than that of fluorine-free emulsion.     

乳化剂在含氟丙烯酸酯乳胶膜中的分布

以阴离子型脂肪醇聚氧乙烯醚硫酸钠(AES)、阳离子型十六烷基-3-甲基氯化铵(CTAB)和反应型乳化剂烷基酰胺乙烯磺酸钠(DNS-86)作为乳化剂制备了三种甲基丙烯酸六氟丁酯和丙烯酸六氟丁酯共聚乳液(PF6MBA-co-F6BA)。通过表面能、原子力显微镜(AFM)和扫描电镜能谱分析(SEM-EDX)对乳胶膜进行表征,研究乳化剂在乳胶膜中的分布。发现阴离子和阳离子乳化剂在成膜过程中向膜-空气面迁移并发生富集,反应型乳化剂在膜中均匀分布;对含氟乳液进行透析后乳化剂的富集减少;经退火处理的乳胶膜的膜-空气面乳化剂富集现象消失。     

自交联封闭性乳液的合成与性能

以双丙酮丙烯酰胺（DAAM）、甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）和甲基丙烯酸（MAA）为共聚单体,采用半连续种子乳液聚合工艺合成自交联封闭性聚丙烯酸酯乳液（PAE）,考察了DAAM和复合乳化剂对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着DAAM含量的增加,乳液聚合稳定性下降,粒径增大,涂膜的耐介质性能和交联度提高,合适的DAAM加入量为总单体质量的3.0%,DAAM和己二酰肼(ADH)的最佳摩尔比为2∶1。采用SDBS+OP-10+OP-40为复合乳化剂体系,选用乳化剂的含量为2.35%,阴/非离子乳化剂质量比为1∶1.25;复合乳化剂在种子、核、壳比例为1.5∶1∶2,制备的乳液具有较好的聚合稳定性（乳液凝胶率低和单体转化率高）,乳液耐电解质（钙离子）稳定性好,涂膜具有优异的封闭性。傅里叶红外光谱（FTIR）表明在涂膜形成过程中DAAM的酮羰基与ADH的酰肼基反应生成腙（C=N）,TEM分析显示乳液的乳胶粒子呈核壳结构,TGA分析发现DAAM改性的PAE降低了涂膜的热稳定性。     

硅烷改性氟代聚丙烯酸酯乳液的制备及其氟碳涂层表面性能

在阴/非离子表面活性剂作用下,将甲基丙烯酸十二氟庚酯(DFMA)与丙烯酸月桂酯(LA)、甲基丙烯酸羟丙酯(HPMA)及γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPMS)在水相进行乳液共聚,合成了一种硅烷改性氟代聚丙烯酸酯(DLHM)乳液。用红外光谱(IR)、核磁共振氢谱(1HNMR)和透射电镜(TEM)等对DLHM的结构及乳液的物化性能进行了表征和测定。再将DLHM乳液制备成氟碳涂层,考察温度、乳液用量对涂层表面性能的影响。结果表明,DLHM乳液具有核壳结构、平均粒径为131 nm、Zeta电位为-24.09 mV。当固化温度为150℃、乳液用量为25 g时,所得涂层性能最佳,与水的接触角达128°,表现出良好的拒水效果。     

Synthesis and characterization of fluorinated polyacrylate latex emulsified with novel surfactants

The fluorinated polyacrylate latex were successfully prepared with semi- continuous seeded emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) and hexafluorobutyl methacrylate (HFMA) which was initiated with potassium persulfate (KPS) initiator and emulsified with the novel mixed surfactants of sodium lauryl glutamate (SLG) and alkylphenol ethoxylates (OP-10). The structure of the resultant latex was confirmed by Fourier transform infrared spectroscopy (FTIR). The particle size of the latex was measured by Zetatrac dynamic light scattering detector. The film of latex was tested by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and contact angle (CA). The optimum conditions of preparing the novel fluorinated polyacrylate latex are optimized and the results are as follows: the amount of emulsifiers is 4.0%; mass ratio of SLG to OP-10 is 1:1, the amount of the initiator is 0.6%. The mass ratio of MMA to BA is 1:1 and the amount of HFMA is 7.0%. In this case, the conversion is high and the polymerization stability is good. In addition, the water resistance and thermal properties of the latex films were improved significantly in comparison with the film of the latex prepared without the fluorinated monomer.     

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     

Glass-transition temperature of a polyacrylate latex film and its water whitening resistance

Polyacrylate latex materials have become a hot area recently in China due to its environmental friendliness. However, the water whitening resistance of the polyacrylate latex products in the market is largely unsatisfactory, which seriously affects the appearance and performance of the latex products. In this work, the effect of glass-transition temperature (T_g) of a polyacrylate latex film on its water whitening resistance was investigated. The light transmittance measurement showed that the higher the T_g of the latex film, the better the water whitening resistance. Atomic force microscope, surface element analysis, static water contact angle measurement, and attenuated total reflection–Fourier transform infrared were used to characterize the accumulation of the emulsifier on the surface of the latex film. It was found that the amount of emulsifier migrated to the surface of the latex film increased with the increase of the T_g of the latex film, that is, the amount of emulsifier remained inside the latex film decreased, thereby reducing its affinity to water. In addition, the higher the T_g of the latex film, the lower the water absorption, also reducing the affinity of the latex film to water. Both work together to improve the water whitening resistance of polyacrylate latex film with higher T_g. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48361.     

Synthesis and characterization of Au/TiO2 core-shell structure nanoparticles

Au/TiO₂ core-shell structure nanoparticles were synthesized by sol-gel process, and the morphology and crystallinity of TiO₂ shell were investigated by TEM and UV-vis absorption spectrometer. Au/TiO₂ core-shell structure nanoparticles could be prepared by the hydrolysis of TOAA (titanium oxide acethylacetonate) in gold sol ethanol solution with water. The thickness of TiO₂ shell on the surface of gold particles was about 1 nm. To investigate the crystallinity of TiO, shell, UV light with 254 nm and radioactive ray of⁶⁰Co were irradiated on the TiO₂-coated gold sol ethanol solution. The surface plasmon band of gold nanoparticles appeared only when the radioactive ray was irradiated on the TiO₂-coated gold sol ethanol solution. From these results, it was found that the TiO, shell was amorphous and the MUA (mercaptoundecanoic acid) layer on the Au particle for its dispersion in ethanol did not act as an obstacle to disturb the movement of electrons onto the surface of Au particles.     

Effect of acrylic acid on water-whitening resistance of polyacrylate latex films and its mechanism

Two groups of polyacrylate latexes with higher (21 ~ 35 °C) or lower (−33 ~ −43 °C) glass transition temperatures (T_g) were prepared by adjusting the monomer ratio of butyl acrylate (BA) and styrene (St), and the effect of acrylic acid (AA) on water-whitening resistance of these latex films was investigated. It was found that the water-whitening resistance of the two groups of latex films was different. With the increase of AA content, the water whitening resistance of the latex films with higher T_g continued to improve, while that of the latex films with lower T_g increased first and then decreased. A series of characterizations, such as light transmittance, water whitening, water absorption, static water contact angle, surface morphology, and optical microscope test of the latex film, and so forth, showed that the reason for this difference was that under higher AA content (≥5%), compared with the polyacrylate latex films with lower T_g, the latex films with higher T_g could reach the saturation state of water absorption quickly, and water in these latex films exhibited continuous and large area distribution, rather than formation of many so-called micro- or nano-scale water sacs that can scatter light as found in the latex films with lower T_g.     

Surface immobilisation of fluorinated polystyrene‐acrylate latex nanoparticles with core–shell structure by crosslinking

Fluorinated polystyrene‐acrylate (PSA) latex nanoparticles with core–shell structure were synthesised by two‐stage seeded emulsion polymerisation method in the presence of reactive emulsifier DNS‐86. Diallyl phthalate (DAP) and Vinyltriethoxysilicone (VTES) were used as crosslinking agent to immobilise the fluorinated copolymer on the surface of the latex film. Fourier transform infrared spectroscopy (FTIR) spectra show that fluorine and siloxane monomers were effectively involved in the emulsion copolymerisation. Transmission electron microscope (TEM) observation shows that the prepared emulsion particles had a core–shell structure with fluorinated copolymer in the shell. X‐ray photoelectron spectroscopy (XPS) analysis reveals that fluorine atom has the tendency of migrating to the film–air interface and the incorporation of VTES helps the migration of fluorine atom towards the film–air interface. Water contact angle (WCA) test proved that DAP and VTES as crosslinking agent can immobilise the fluorinated copolymer on the surface of the latex films. © 2011 Canadian Society for Chemical Engineering     

外墙涂料用新型核-壳丙烯酸酯乳液的合成研究

采用半连续种子乳液聚合技术、改进单体加料方式,制备出高弹性、高耐水性、高稳定性的核-壳丙烯酸乳液。讨论了软硬单体的比例、乳化剂、功能性单体、耐水性单体等对乳液胶膜吸水率及延伸率的影响,并对合成的乳液进行了表征。结果表明合成的核-壳乳液有更好的拉伸性能和耐水性。