Fabrication of an epoxy graft poly(St-acrylate) composite latex and its functional properties as a steel coating

A novel method for preparing epoxy graft poly(St-acrylate) composite latex with high graft ratio has been devised. First, esterification was carried out between acrylic acid and an epoxy resin using the monomer as the solvent. The obtained sample, still in solution in the monomer, was emulsified to miniemulsion droplets together with other monomers. Finally, the epoxy graft acrylate composite latex was prepared by miniemulsion copolymerization. This technology will eliminate pollution arising from the organic solvent when solvent-borne systems are used. The enhanced graft ratio was confirmed by FTIR and ¹H NMR measurements. The results indicated that the acrylic monomer was grafted onto the epoxy chain. TEM showed the graft composite latex to have a spherical structure with diameter 100 nm. The adhesive performance and anti-corrosive properties on a steel substrate, as measured by salt-spray resistance, were maximized when 4.0% acrylic acid was added to the epoxy resin. Dynamic mechanical analysis (DMA) has been employed to test the damping properties of the composite latex coatings. It was interesting that the tan δ peak values of the coatings were as high as 2.15, clearly exceeding those of general damping materials. Our findings suggest great potential for the composite latex in the field of functional steel coatings.     

Preparation and characterization of waterborne epoxy latexes and epoxy/(silica sol) composites

A series of waterborne epoxy latexes was synthesized, and epoxy/(silica sol) composite latexes were prepared. The effects of functional monomer methacrylic acid (MAA) and silica sol on the latex particle size, morphology, and stability were investigated. With increasing amounts of MAA, the conversion rate increased, the particle size reduced, and the viscosity of the epoxy latexes increased. The epoxy latexes had storage stability and could be stored at room temperature for more than 6 months with a solid content variation of less than 1%. For the (silica sol)‐modified waterborne epoxy latexes, the effects of preparation techniques and silica sol content on the latexes and latex films were investigated. When the silica sol content increased, the particle size of the composite latexes decreased. The morphology investigation showed that when the silica sol content increased, the uneven surface level of the latex films was increased. The increase of elemental silica on the surface was in accord with the improvement of the water resistance of the composite latex films. The heat resistance of these films was improved as well, and their overall performance was better than that of the epoxy latex films. J. VINYL ADDIT. TECHNOL., 20:57–64, 2014. © 2014 Society of Plastics Engineers     

Controlled preparation and properties of acrylic acid epoxy-acrylate composite emulsion for self-crosslinking coatings

A stable epoxy-acrylate composite latex was successfully prepared through emulsion polymerization of modified epoxy acrylic (EPAC) oligomer with acrylate monomer. The EPAC oligomer was obtained using active acrylic acid (AA) to react with epoxy resin. And by regulating the reaction degree of the active hydrogen of AA and epoxide group, there is the acquisition of terminal double bond that gives EPAC reactivity, together with the partial retention of the epoxide group that enables self-crosslinking during film formation. The structural conformation of the oligomer was ascertained by Fourier transform infrared (FTIR) spectroscopy. The factors influencing the stability of the epoxy-acrylate composite latex were investigated. The epoxy-acrylate composite latex was the most stable when methyl acrylic acid was 1.5 wt% and modified EPAC oligomer was 15 wt% of the total monomer weight. The morphology and property of the composite latex films were characterized by scanning electron microscopy, transmission electron microscopy (TEM), and temperature-modulated differential scanning calorimetry (TOPEM-DSC). The results confirm that there is successful emulsion copolymerization between modified EPAC oligomer and acrylate monomer. TEM show that the particles of epoxy-acrylate composite have a core-shell structure, and there is no free epoxy resin. The FTIR and TOPEM-DSC results reveal that the copolymer emulsion possesses self-crosslinking ability. During film formation, self-crosslinking reaction occurs between epoxide groups with carboxyl groups, giving exothermal phenomena. The thermal stability as well as the corrosion resistance of the films was analyzed. The results show outstanding thermal stability as well as corrosion resistance attributable to the crosslinking reticulation structure. It is envisaged that the epoxy-acrylate composite latex has great potential in the development of high-performance aqueous coatings.     

Waterborne oil‐modified polyurethane coatings via hybrid miniemulsion polymerization

As part of a wider effort to develop a new class of waterborne coatings, hybrid miniemulsion polymerization was carried out with acrylic monomers (methyl methacrylate, butyl acrylate, and acrylic acid) in the presence of oil‐modified polyurethane resin. Latexes with different ratios of resin to acrylic monomers were synthesized. The monomer emulsions prepared for hybrid miniemulsion polymerization showed excellent shelf‐life stability (>5 months) and the polymerization was run free of coagulation. Solvent extraction indicated that the grafting efficiency of polyacrylics was greater than 29% for all the samples produced. A ¹³C solution NMR spectrum showed that a substantial fraction of the original carbon double bonds (>61%) in oil‐modified polyurethane remained after polymerization for film curing. Films obtained from the latexes presented good adhesion properties and fair hardness properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 105–114, 2000     

环氧改性苯丙乳液的制备与性能研究

采用半连续种子乳液聚合法制得环氧改性苯丙乳液。研究了环氧树脂、功能单体、引发剂、乳化剂用量对乳液性能的影响。结果表明：环氧树脂用量为单体总量的9％,丙烯酸用量为单体总量2％,硅烷偶联剂A151用量为单体总量的1．5％,引发剂用量为单体总量的0．5％,乳化剂用量为单体总量4％的时得到的乳液具有优良的综合性能。     

Polymeric coatings based on acrylic resin latexes from miniemulsion polymerization using hydrocarbon resins as osmotic agents

Waterborne acrylic resins with a solid content higher than 40 wt % were obtained by miniemulsion polymerization of methyl methacrylate, butyl acrylate, and acrylic acid using a hydrocarbon coumarone–indene resin (HCR) as osmotic agent. HCR is a cheap polymer widely used for coatings and pressure‐sensitive adhesives. The resin leads to a higher hydrophobicity for the acrylic latex film and acts as osmotic agent in miniemulsion polymerization preventing Ostwald ripening, leading to latexes with particle sizes, size distributions, and stability comparable to those obtained using n‐hexadecane as osmotic agent. However, the monomer conversion and molecular weight were lower, indicating the occurrence of a chain‐transfer reaction. Atomic force microscopy analysis demonstrated that a smooth film surface with phase‐separated morphology was formed when using HCR. Faster film hardness development was achieved with HCR comparing with hexadecane. Compared with market standard in a paint formulation, a similar performance was achieved. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40569.     

Preparation and reticulation of styrene acrylic/epoxy complex latex

The styrene acrylic/epoxy (SA/EP) complex latex with high content of epoxy resin was successfully prepared through emulsion polymerization initiated by both water-soluble and oil-soluble initiators. The resulting complex latex demonstrated regular spherical morphology with a diameter ranging 150–300 nm and with a narrow size distribution. The compatibility between epoxy and styrene acrylic improved due to the styrene acrylic grafting epoxy formation during grafting copolymerization. The factors influencing the structure and storage time of the complex latex were investigated and the corresponding mechanism was revealed. The SA/EP complex latex can form crosslinking structure with epoxy curing agent at room temperature. The crosslinked complex latex film shows good mechanical properties and excellent chemical resistance. These SA/EP complex latexes show great potential in developing high-performance aqueous paints and adhesive.     

水性环氧丙烯酸酯乳液涂层成膜性能

采用细乳液聚合法制备了环氧丙烯酸酯复合乳液,考察了固化温度、固化时间及磷酸酯乳化剂含量对环氧丙烯酸酯复合涂膜性能的影响,结果表明环氧丙烯酸酯复合乳胶粒子呈均匀的球形结构,且平均粒径分布在150 nm左右。当固化温度为120℃、固化时间为2 h、磷酸酯乳化剂含量为3%时,涂层的耐腐蚀性较好。研究了复合乳液的成膜过程和防腐蚀机理,通过复合乳液与金属底材形成致密的钝化膜,阻隔水分子和无机离子的浸入,提高了涂层的防腐性能。     

聚苯乙烯-丙烯酸丁酯/八异辛基倍半硅氧烷复合乳液的制备及稳定性研究

用细乳液聚合方法制备了聚苯乙烯-丙烯酸丁酯/八异辛基倍半硅氧烷复合乳液(PS t-BA/PO SS),探讨了八异辛基倍半硅氧烷在乳液中的含量对复合乳胶粒的形态、平均粒径及分布以及乳液稳定性的影响。结果表明复合乳胶粒子平均粒径为70~100nm,PO SS的含量对乳胶粒的形态和粒径分布有明显的影响,复合乳液具有良好的稀释稳定性和离心稳定性。     

Morphology and Characterization of Epoxy-acrylate Composite Particles

Summary  Epoxy-acrylate sample was prepared by two-stage feed emulsion polymerization. Gel permeation chromatography (GPC) and Ultraviolet-Visible (UV-Vis) spectra indicated the acrylic and styrene monomer were grafted onto epoxy resin. Transmission electron microscope (TEM) showed that epoxy-acrylate composite particles with different epoxy resin content stained by pH1.5 phosphotungstic acid (PTA) had an obvious core-shell structure, with styrene-acrylate as the core and epoxy resin as the shell. TEM micrographs also showed the acrylate cores concentrically or eccentrically were positioned inside epoxy resin shells, which was consonant with the particle structures designed. But the Epoxy Resin/Methyl Methacrylate (EP/MMA) particles showed a strange quadrangle-like structure and Epoxy Resin/Methyl Methacrylate/ Butyl Acrylate (EP/MMA/BA) particles showed a hexagon-like structure, which were different from the normal particle structures.     

一种丙烯酸改性乳化环氧树脂的制备与研究

提供了一种制备改性环氧树脂乳液的新方法,以丙烯酸酯类为聚合性单体,加入环氧树脂,利用乳液聚合方法制成了环氧树脂含量达50％的丙烯酸酯改性环氧树脂乳液。通过测试交联度,证明环氧树脂确实参与了聚合反应。同时,还对乳化剂、功能性单体以及环氧树脂含量对乳液稳定性、产品收率、吸水性以及各项力学性能的影响问题进行了研究,得出：丙烯酸对环氧树脂的聚合交联起到了决定性的作用,丙烯酰胺的引入大大提高了乳液的稳定性和力学性能,环氧树脂含量越多产品性能越接近纯环氧树脂,聚合应采用阴、非离子复合乳化剂。     

In situ preparation and properties of high‐solid‐content and low‐viscosity poly(methyl methacrylate/n‐butyl acrylate/acrylic acid)/poly(styrene/acrylic acid) composite latexes

With monodispersed poly(methyl methacrylate/n‐butyl acrylate/acrylic acid) [P(MMA/BA/AA)] seeded latex with a particle size of 485 nm and a solid content of 50 wt % as a medium, a series of stable P(MMA/BA/AA)/poly(styrene/acrylic acid) composite latexes with a high solid content (70 wt %) and low viscosities (500–1000 mPa · s when the shear rate was 21 s^?1) was prepared in situ via simple two‐step semicontinuous monomer adding technology. The coagulum ratio of polymerization was about 0.05 wt %. The particle size distribution of such latexes was bimodal, in which the large particle was about 589 nm and the small one was about 80 nm. The latexes combined good mechanical properties with good film‐forming properties. Differential scanning calorimetry showed that the corresponding latex film had a two‐phase structure. The morphology of the latex film was characterized with atomic force microscopy and scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1815–1825, 2007     

Facile fabrication and modification of epoxy acrylate latexes by epoxy resin and silane coupling agent

For the purpose of obtaining solvent-free epoxy acrylate latexes of good stability and excellent integrated performance, the epoxy acrylate latexes were fabricated using facile semi-continuous emulsion polymerization with varying amounts of epoxy resin and were modified by a silane coupling agent γ-methacryloxypropyltrimethoxysilane (KH-570). The effects of epoxy resin and KH-570 amounts on the performance of latexes and films were investigated from the aspects of particle size, morphology, tensile measurements, resistance properties, adhesion force, and thermal behavior. The results indicated that the acrylate monomers did graft onto the molecular chain of E-51 characterized by both epoxy value and Fourier transform infrared. Additionally, an emulsion of 80–100 nm particle size with a narrow distribution was obtained. The latex films retain resistances to satisfactory water, acid, alkali, and alcohol while maintaining good thermal stability, adhesion force, and flexibility. The importing of KH-570 could reinforce the spatial structure and cross-linking density and then improve the tensile strength of the latex films properly while keeping other performances well. This work provides a facile pathway for the optimized performance for epoxy acrylate latexes, and represents a tendency for environmental protection.     

Synthesis of epoxy resin–silica nanocomposites provided from perhydropolysilazane as a curing reagent and the precursor of silica domain

Epoxy resin–silica nanocomposites with spherical silica domains with 29.0 nm in diameter in an epoxy resin matrix were synthesized from Bisphenol‐A type epoxide monomer, 2,2‐bis(4‐glycidyloxyphenyl)propane (DGEBA), and perhydropolysilazane (PHPS, ? [Si₂? NH]_n? ). The volume fraction of silica domain in the composite varied from 5.4 to 37.8 vol % by varying the feed ratio of PHPS to the epoxide monomer. The reaction mechanism of epoxy group and PHPS was investigated by using glycidyl methacrylate as a model compound of the epoxy monomer by ¹H‐nucular magnetic resonance and Fourier transform infrared spectrometry. Ammonia gas provided by the decomposition of PHPS with moisture converted PHPS to silica and cured the epoxy monomer. The curing of epoxy monomer preferably proceeded than the conversion of silica. The addition of 1,4‐diaminobutane drastically accelerated the rate of curing; white and hard epoxy resin–silica nanocomposites were obtained. The good thermal stability of the composite prepared with DGEBA/PHPS/1,4‐diaminobutane was observed by thermogravimetric analysis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

硅丙乳液制备方法及稳定性研究进展

综述了硅丙乳液制备方法的研究进展。重点介绍了无皂乳液聚合、细乳液聚合及乳液互穿聚合物网络;讨论了影响硅丙乳液稳定性的因素,如有机硅单体、乳化剂及引发剂种类,乳液聚合工艺、聚合反应温度;并对该研究领域进行了展望。     

Preparation of acrylic copolymer latex modified by fluorine,silicon, and epoxy resin

A series of modified acrylic copolymer latices have been prepared through a semicontinuous emulsion copolymerization process with a variety of hydrocarbon monomers and (perfluoroalkyl) methyl methacrylate, vinyltriethoxysilicone, and phenol‐formaldehyde epoxy resin. The composition of copolymer was analyzed by fluoride ion selective electrode analysis, ¹⁹F NMR, FTIR, crosslinking degree determination, and epoxy‐acetone method. The results showed that the fluorine monomer, silicon monomer and epoxy resin had copolymerized with acrylic monomers. The optimum mass ratio between the curing agent TEA and epoxy resin was 1.36 : 6. The determination results of stabilities (electrolyte stability, freeze‐thaw stability, high temperature stability and mechanical stability) of latices showed that the incorporation of fluorine monomer and silicon monomer improved freeze‐thaw stability and mechanical stability, whereas the epoxy resin did not have obvious effect on the stabilities. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

氟聚合物-聚丙烯酸酯互穿网络聚合物乳液的合成

采用互穿网络的方法来制备乳液．以聚四氟乙烯为种子乳液．用丙烯酸酯单体对其进行溶胀．加入聚偏氟乙烯后滴加单体聚合，整个实验中采用阴离子乳化剂和非离子乳化剂复配体系、并且添加少量的保护胶。通过正交实验得到涂层具有最大接触角的聚合配方．然后用红外光谱、扫描电镜和透射电镜对乳液涂层进行表征．结果表明氟聚合物与丙烯酸酯之间有较好的相容性．乳液稳定且乳液涂层性能优异。     

Polymeric particles prepared with fluorinated surfmer

Fluoro-containing particles have been obtained by miniemulsion polymerization of styrene and n-butyl methacrylate in presence of fluorinated monomer mono-fluoroalkyl maleate (MFM) which acts as a surfmer providing efficient stability to obtained dispersion and functionalization of particle surface with fluoro-groups. Increase of the MFM concentration in reaction mixture reduces the particle size and dispersions with narrower particle size distribution can be obtained. Blends of fluorinated latexes with styrene-butadiene copolymer latex were examined with regard to formation of low free energy surfaces. It has been shown that blends containing MFM-functionalized polymeric particles possess more hydrophobic surfaces then similar latex films, where particles prepared by polymerization of expensive fluorinated monomer have been applied.     

水基型路面标线涂料的研制及其应用

采用合成的具有核壳结构的环丙乳液配制的水性路面标线涂料 ;讨论了乳化剂、环氧树脂、丙烯酸酯功能单体的用量对乳液性能的影响和对涂料的干结时间、耐水性能及施工泛黄的影响因素 ,并提出了相应的解决措施。     

Adhesion enhancement in waterborne acrylic latex binders synthesized with phosphate methacrylate monomers

The effect of the addition of a phosphoric acid group containing monomer on polymerization kinetics, copolymer microstructure and end-use properties of a latex prepared by seeded emulsion polymerization of MMA/BA/MAA/AAEMA/SIPOMER PAM100 was studied. It was found that despite of the surface activity of the phosphated monomer, the polymerization kinetics was not affected. Gel content increased with the concentration of phosphate monomer due mainly to the presence of divinyl ester phospate impurities. Gel improved the chemical resistance of the latex films. However, the most affected property was adhesion. Increasing amounts of the phosphated monomer led to a strong enhancement of the adhesion due to chemical interactions established with the metal surface. It was also found that the feeding strategy of the phosphated monomer played an important role in the adhesion enhancement. Latexes synthesized using a delayed addition of the phosphate monomer showed better performance than latexes prepared following a conventional addition strategy. The latexes synthesized during the investigation were evaluated as binders in a primer formulation. A primer with good adhesive and corrosion resistance properties was achieved using a 5 wt.% of the phosphated monomer.