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     

有机硅改性-丙烯酸酯共聚乳液的制备与性能研究

文章研究了有机硅单体与丙烯酸类单体的乳液聚合反应,制备出高性能的改性丙烯酸酯乳液。主要讨论了乳化剂、引发剂、有机硅加入方式及用量对乳液性能的影响。用有机硅改性丙烯酸酯乳液制成的涂料具有优越的耐水性,其耐洗刷性可达6万次。     

纳米SiO_2/聚丙烯酸酯组装杂化乳液的合成及表征

通过乳液聚合法成功合成了纳米SiO2/聚丙烯酸酯杂化乳液。首先将纳米SiO2经过表面官能团化处理,使其表面含有活性官能团,然后经过乳液聚合使丙烯酸酯单体在纳米SiO2表面引发聚合,合成了具有核壳结构的纳米杂化乳液。采用透射电子显微镜(TEM)对乳液的微观结构进行了表征,并对胶膜进行了机械力学性能测试和表面润湿性能测试。结果表明纳米SiO2的表面官能团化处理改善了纳米粒子在乳液中的稳定性,当纳米SiO2质量分数为0 2%时,杂化乳液胶膜的拉伸强度和断裂伸长率同时达到最大值。其表面润湿性与SiO2质量分数有关,SiO2质量分数为0 5%时其杂化乳胶膜的接触角最大,耐水性最好。     

松香改性丙烯酸酯乳液的合成及其在PVC地板胶的应用

采用半连续种子乳液聚合的方法制备了一种具有核壳结构的松香树脂改性PVC地板胶用丙烯酸酯聚合物乳液,讨论了松香树脂质量分数、松香树脂加入方式、核壳质量比等因素对聚合物乳液性能的影响。结果表明,当松香树脂质量分数为2%,核壳单体的质量比为1∶2时,乳液的初黏性(#33)达到1.3 cm,粘接强度达到0.32 MPa。     

水基改性环氧树脂涂料的合成研究

研究了以环氧树脂Ｅ－ ４４（ 简称为环氧树脂） 为主要原料, 对水基改性环氧树脂涂料———环氧磷酸酯 丙烯酸接枝共聚物的合成反应, 探讨了丙烯酸及其酯, 苯乙烯和引发剂的用量,接枝反应温度, 接枝反应时间等因素对该接枝共聚物水分散稳定性的影响, 确定了较佳的工艺条件。并对该接枝共聚物进行了有关的产品性能和应用性能检测。     

Synthesis and characterization of latexes based on copolymers BA\MMA\DAAM and BA\MMA\VEOVA-10\DAAM and the corresponding 1K crosslinkable binder using the adipic acid dihydrazide as crosslinking agent

In this study stable latexes of butyl acrylate (BA)/methyl methacrylate (MMA)/diacetone acrylamide (DAAM) copolymers and BA/MMA/vinyl neo-decanoate (VeoVa-10)/DAAM copolymers were synthesized by a modified semi-continuous microemulsion copolymerization. Ammonium persulfate was used as initiator and a redox system for post-polymerization to reduce the free monomers content. Methacrylic acid (MMA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylic acid (AA) and various “green” industrial anionic, non-ionic and anionic polymerizable surfactants free of alkylphenol ethoxylates (APEO free) were tested as a stabilizing system. The resulting latexes, their corresponding self-1K crosslinkable binder using the adipic acid (ADH) dihydrazide as crosslinking agent and their films were characterized with rotational viscometer, dynamic light scattering, gloss, dynamic mechanical analysis, minimum film forming temperature (MFFT), water resistance and swelling in methyl ethyl ketone measurements. The experiments showed that BA\MMA\VEOVA-10\DAAM latexes prepared with methacrylic acid and a polymerizable surfactant showed zero coagulation during polymerization. Their corresponding 1K crosslinkable binder with ADH were stable over 6 months storage time and showed good all around properties that makes them suitable for use in friendly to the environment coatings.     

Study of the properties of novel hybrid coatings under the influence of phase compatibility

In this article, a series of hybrid coatings were prepared and characterized. At first, polydimethylsiloxane modified with siliane coupling agent was copolymerized with acrylate monomers by free radical polymerization to get the hybrid resins. Due to the combination of covalent bond, the prepared hybrid resins were uniform and transparent. Then a series of hybrid resins were cured with tetraethoxysilane and dibutyltin dilaurate as the crosslinker and catalyst, respectively. The blends were loaded onto the substrate, such as tin plate, steel panels, or flat glass, and cured by heating to form hybrid coatings. To study the factors on the properties of the prepared hybrid resins and cured coatings, various measurements were carried out, such as FTIR, TGA, DSC, laser optical microscope, water contact angles, pencil scratch hardness, and the electrochemistry test. Thanks to the combination of covalent bond, the two components dispersed uniformly in the prepared hybrid resins and no cracks were observed from the cured hybrid coatings with an optical microscope. With excellent mechanical properties, thermal stability, corrosion resistance, and hydrophobic property, the prepared hybrid coatings can find application in the heavy-duty chemical industry.     

Silicone-polyacrylate composite latex particles. Particles formation and film properties

Composite latex particles with a polydimethylsiloxane PDMS core and a poly(methyl methacrylate-co-n-butyl acrylate) P(MMA-BA) copolymer shell were synthesized by seeded emulsion polymerization using the PDMS latex as the seed. The compatibility between the two polymer phases was changed by introducing vinyl groups in the latex core. Monomer conversions and particle size evolution were monitored to see the influence of the nature of the core functionality on the polymerization kinetics and on the extent of secondary nucleation. Particle morphology was characterized by cryo-transmission electron microscopy. The P(MMA-BA) copolymer formed a regular shell around the PDMS seed, whereas nonuniform coatings were formed when vinyl functionalities were introduced into the seed. Films were produced from the latexes, and their surface property was analyzed by X-ray photoelectron spectroscopy and contact angle measurements. It was shown that the PDMS component segregated to the polymer/air interface and that the extent of segregation depended on the original particles structure. Because PDMS has a very low glass transition temperature, it can easily diffuse throughout the film material. However, protected by an acrylic shell, polymer diffusion is significantly hindered and the film then displays all the characteristic properties of the acrylic copolymer. The surface composition of the films formed by the structured particles which PDMS core was not totally covered by the polyacrylate, was found to be intermediate between the composition of the films issued from the core-shell latexes and that of the films produced from blends of pure polyacrylate and PDMS latexes.     

有机硅氧烷改性丙烯酸酯微乳液的合成与表征

采用种子乳液聚合法,以阴离子乳化剂DF-2和非离子乳化剂OP-10作为复合乳化剂,以FeSO4、K2S2O8和甲醛合次亚硫酸氢钠(SFS)作为氧化-还原引发剂,在65℃合成了有机硅改性丙烯酸酯聚合物微乳液。实验采用单体滴加工艺,用COULTERLS粒度仪和傅里叶变换红外光谱仪分别测定了共聚乳液的粒径分布和产物的结构,研究了加料方式、配方组成及操作方式对聚合稳定性、乳液的粒径分布以及产物性能的影响。结果表明,采用单体滴加工艺能得到平均粒径为50～80nm的单峰窄分布微乳液,并有效地将有机硅氧烷引入到共聚物大分子中。     

涂料用有机硅改性丙烯酸树脂的合成与研究

以溶液聚合法合成了有机硅改性丙烯酸树脂，选择不同种类的硅单体进行实验，研究了硅单体用量对涂膜吸水率的影响以及不同软硬丙烯酸类单体比例对涂膜柔韧性及吸水率的影响，并对涂膜进行了红外分析和扫描电镜分析。结果表明：由接枝反应改性的有机硅丙烯酸酯涂料具有优良的性能。     

聚硅氧烷/聚丙烯酸酯共聚乳液的合成与表征

合成了含氢聚甲基硅氧烷／聚丙烯酸酯共聚乳液。研究了聚合工艺，配组成及操作方式对聚合稳定性，动力学，乳液的粒径分布和产物性能的影响。采用部分预乳化单体滴加法（工艺A）的部分纯单体滴加法（工艺B）两种工艺，聚硅氧烷采用高速预乳化滴加进料方式。用COULTER LS粒径仪和Nicolet傅立叶变换红外光谱仪分别测定共取乳液的粒径分布和产物的结构。研究结果表明，采用A，B两种工艺均能得到平均粒径为0.101-0.103μm的单峰窄分布共聚乳液，并能有效地将含氢聚硅氧烷引入了到共取物大分子中。含氢聚硅氧烷的引入量为3％（质量）时，共聚物涂膜具有柔软，滑爽和强度高等优点。     

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.     

Modification research on the peel strength of the acrylate emulsion pressure‐sensitive adhesives

Pressure‐sensitive adhesives (PSAs) were produced with latexes synthesized via starved semibatch emulsion polymerization processes with butyl acrylate, three different kinds of hard monomers [styrene (St), methyl methacrylate, and 2‐phenoxy ethyl methacrylate (SR340)], acrylic acid, and 2‐hydroxy ethyl acrylate. The management of both the copolymer composition and the polymerization process allowed us to control the behavior of the PSAs. For the acrylate latexes, the types of hard monomers and their contents, the concentration of buffer [bicarbonate (NaHCO₃)], and three kinds of semibatch processes were manipulated to modify the polymer properties. The performance of the PSA films cast from these latexes was evaluated by the peel strength. The results show that the PSA prepared with St exhibited the highest peel strength among the three hard monomers, and the latex synthesized by SR340 showed the largest gel content compared with the other two hard monomers. With increasing buffer, the latex particle size increased, and the peel strength initially increased to a maximum and then decreased. Nevertheless, the stability of the latexes decreased with increasing buffer concentration. In addition, the effects of the three kinds of semibatch processes on the peel strength of the PSA were also evaluated. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40095.     

Effect of functional monomer on the stability and film properties of thermosetting core-shell latexes

Functionalized core-shell latexes were prepared by copolymerization of butyl acrylate and methyl methacrylate with 2-hydroxyethyl methacrylate (HEMA) or methacrylic acid (MAA), which were added during the first or second stages of polymerization, respectively. The HEMA and MAA concentrations were increased while the equivalent ratio of functional groups remained constant. Colloidal stability, particle size, particle size distribution, film properties and morphology were studied as functions of functional monomer content. The upper limit functionality content was limited by the stability of the system during synthesis. A bimodal particle size distribution was observed for high concentrations of functional monomers. Increase in carboxyl and hydroxyl functionalities improved tensile strength and modulus for un-crosslinked films, and generally higher tensile strength, tensile modulus and storage modulus at high temperature were obtained after the functional latexes were crosslinked with a cycloaliphatic diepoxide.     

丙烯酸酯预反应体系制备常温无溶剂反应性涂料

利用丙烯酸酯树脂预聚物与交联单体在引发剂和促进剂的作用下进行自由基聚合反应交联成膜,制备了一种低黏度、高固含量、表干时间短、低污染、硬度高、柔韧性好、附着力强、耐候性好的涂料。着重探讨了丙烯酸酯树脂预聚物的合成,并对涂膜性能进行了测试,找到了控制预聚物黏度的方法及涂料的适宜配方,可为丙烯酸类路标涂料的生产应用提供一定的借鉴。     

环氧树脂改性含氟丙烯酸酯/有机蒙脱土复合乳液的研究

以丙烯酸六氟丁酯(HFBM)为功能性单体,有机蒙脱土为改性剂,甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和丙烯酸(AA)为主要单体,采用乳液聚合法合成了含氟丙烯酸酯/有机蒙脱土(PFA/OMMT)复合乳液,并用环氧树脂乳液对其进行共混改性,探讨了环氧树脂的环氧值和用量对共混乳液所成漆膜性能的影响.结果表明:环氧值越小...     

环氧丙烯酸酯乳液的研制

采用复合乳化剂聚合工艺，制得丙烯酸酯类改性环氧树脂乳液。研究了乳化剂、反应温度、引发剂的用量、环氧树脂的种类及用量、软硬单体的比例、三乙烯四胺用量等对丙烯酸酯类改性环氧树脂乳液综合性能的影响，确定了适宜的反应条件和配方。     

纸塑复合用醋丙乳液的研制

以丙烯酸丁酯、丙烯酸异辛酯、乙酸乙烯酯为主要单体,以丙烯酸为功能单体,采用预乳化种子乳液聚合法成功合成了性能优良的醋丙乳液纸塑复合胶粘剂。着重讨论了单体的选择、软硬单体配比、乳化剂以及功能单体的用量等因素对乳液性能的影响。研究结果表明,软硬单体质量比为45：50～50：45,乳化剂用量为单体总量的3％,功能单体用量为6％时,制备的乳液具有较好的纸塑粘接性能。     

Preparation and characterization of the complex latex formed through complexation of two polymer latexes with chemically complementary structure

In this study, the intermacromolecular complexation of two polymers with chemically complementary structures in the latex state and the interparticle interactions were probed. Two latexes—a polydimethylsiloxane (PDMS)/poly(vinyl acetate‐co‐butyl acrylate) system, named PA latex, and a PDMS/poly(methacrylic acid) system, named PB latex—were prepared by seeded emulsion polymerization and the complex latexes were obtained through complexation of the PA latex with the PB latex. The properties of the obtained complex latexes were investigated using surface tension and viscosity measurements. The surface structure and composition of coatings obtained from the latexes were analyzed by X‐ray photoelectron spectroscopy and scanning probe microscopy. The results confirmed that there are interactions between the (or groups in PA and the groups in PB. The interactions result in unique properties of the polymer latex and lead to a formation of a new structure of the coatings. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1405–1411, 2003     

Hybrid acrylic–polyurethane latexes: Emulsion versus miniemulsion polymerization

Two kinds of hybrid acrylic–polyurethane (PUA) latexes are compared according to their synthesis and properties. The acrylic part is a copolymer of styrene, methyl methacrylate, and butyl acrylate. The PUAs are based on the polycondensation of isophorone diisocyanate and poly(propylene glycol) using butanediol and ethylene diamine as chain extenders. The first class result from the polymerization of miniemulsions of solutions of PU in the mixture of monomers using benzoyl peroxide as an initiator at 80°C. In the second class PUs modified by neutralized dimethylolpropionic acid are used as seeds and emulsifiers for emulsion polymerization of the monomer mixtures initiated with azobisisobutyronitrile at 75°C. The polymerization kinetics are compared, as well as the morphology of the latex particles. Films are obtained upon coalescence of these latexes, and the surface composition of these films and their tensile properties are studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3927–3941, 2006