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     

Grafting mechanisms in hybrid miniemulsion polymerization

The ultimate objective of hybrid miniemulsion polymerization is to produce a water‐based crosslinkable coating through in situ grafting of a free radical growing acrylic polymer with an unsaturated resin. Certain authors have reported low grafting while others have reported higher. This article explores the factors that influence the grafting tendencies of these systems. Methacrylates such as methyl methacrylate (MMA) have a sterically hindered radical center that lowers its reactivity toward unsaturated resin. This steric hindrance from the methyl group forces grafting of this type of monomer to occur by abstraction of a hydrogen allylic to a resinous double bond. This chain transfer produces a relatively inactive radical on the resin that reduces the grafting efficiency. The transfer process also inherently produces some degree of terminated PMMA polymer within the particle. Grafting occurs in this type of system through termination of living PMMA chains with that radical produced on the resin. For relatively water‐soluble monomers such as MMA, grafting efficiency is further lessened by homogeneous nucleation resulting from the monomer hydrophilicity. These newly created particles cannot contain alkyd due to its hydrophobicity and thus inability to transport across the aqueous phase, and hence cannot produce grafted polymer. Nonetheless, degree of grafting of nearly 50% was observed in these systems. For hybrid systems involving an acrylate monomer such as butyl acrylate (BA), virtually complete grafting with alkyd was observed. This is due to the uninhibited BA radical center allowing the molecule to add directly through a resin double bond. This process offers the possibility for complete grafting. Homogeneous nucleation is not involved in this system due to the insolubility of BA in the aqueous phase. Resin double bond content and degree of conjugation also play an integral role in the grafting process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1825–1836, 2003     

Preparation of epoxy resin/acrylic composite latexes by miniemulsion polymerization method

Epoxy resin/acrylic composite latexes were prepared by miniemulsion polymerization. Epoxy resins have a functional epoxy group in them and excellent characteristics, such as heat resistance and good adhesion. Acrylic latexes have weather and water resistance. Combining the epoxy resin and the acrylic latex was an attempt to actualize these advantages. The miniemulsion polymerization method was effective in obtaining the composite latex. A less than 500‐nm droplet size for the monomer preemulsion was necessary to obtain the latex in a stable manner. Dimethylaminoethylmethacrylate and methacrylic acid as the reactive functional monomer with an epoxy group were introduced to the latexes. The effect of the polymerization method of these functional groups on the properties of latexes and their films was investigated. The latex prepared by the two‐stage polymerization method had good polymerization stability, storage stability, and solvent resistance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 128–133, 2001     

细乳液聚合制备有机硅/丙烯酸酯乳液及其性能

利用细乳液聚合技术设计并制备了不同有机硅含量的有机硅改性丙烯酸酯共聚物稳定乳液.通过细乳液共聚合反应在丙烯酸酯类聚合物主链上引入硅氧烷侧基,该基团水解后与羟基硅油缩合,引入聚硅氧烷接枝链.研究表明：（1）γ-甲基丙烯酰氧丙基三甲氧基硅烷(MPMS)比乙烯基三乙氧基硅烷(VTES)更适合在本体系中用作共聚有机硅单体;（2）聚合过程中,乳液稳定,凝聚物很少;（3）羟基硅油能较好地接枝到丙烯酸酯聚合物主链上,接枝率在50%左右;（4）有机硅的引入减少聚合物涂层的吸水率,表面的水接触角也明显增大,显示出较强的疏水特性.有机硅含量在10%（质量）时,聚合物涂层即可显示很好的憎水特性,随着有机硅含量进一步提高,憎水特性可进一步提高,聚合物涂膜吸水率可低至5%,水接触角可高达105°.     

影响涂料用DCPD型不饱和聚酯涂料凝胶时间的因素

主要从不饱和聚酯树脂酸值,苯乙烯、促进剂、引发剂的用量,颜填料的选择与用量等方面进行了研究,考察这些因素对气干性DCPD型不饱和聚酯涂料凝胶时间的影响,为不饱和聚酯涂料的实际生产和应用提供参考。     

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.     

微小乳液聚合制备丙烯酸酯杂化聚氨酯分散液

微小乳液聚合工艺技术在25~30年前即已问世,但用于丙烯酸酯杂化聚氨酯分散液的制备仅有10年历史。用该工艺技术可有效制得稳定的纳米级丙烯酸酯杂化聚氨酯分散液,其性能独特。本文阐述了微小乳液聚合工艺的原理、影响因素、存在问题和解决措施,并以实例说明之。     

Emulsion and miniemulsion copolymerization of acrylic monomers in the presence of alkyd resin

Emulsion and miniemulsion copolymerizations were carried out with acrylic monomers (methyl methacrylate, butyl acrylate, and acrylic acid) in the presence of an alkyd resin. Poly(methyl methacrylate) was used as a hydrophobe or cosurfactant in the miniemulsion reactions. The results demonstrate that miniemulsion polymerization is the preferred process, probably because of mass transport limitations of the alkyd in the conventional emulsion polymerization reactions. The monomer emulsions prepared for the miniemulsion reactions were much more stable and the polymerizations were free of coagulum. Reaction rates, particle size characteristics, grafting efficiencies, and some film properties were measured. © 1996 John Wiley & Sons, Inc.     

环保半无机丙烯酸树脂型电工钢绝缘涂料的研究

系统研究了添加磷酸锌亚微米超细粉末的半无机丙烯酸树脂涂料的固化及其电工性能,综合扫描电镜、热失重、盐雾实验、硬度和附着性能的试验结果,采用添加亚微米磷酸锌无机颗粒的丙烯酸树脂涂料,这是一种优良的电工铜绝缘涂料,优于目前广泛采用的铬酸盐绝缘涂料。     

合成不饱和聚酯树脂的新型催化剂

介绍用自制催化剂合成通用型不饱和聚酯树脂的新工艺，克服了传统工艺的缺点，使反应速度加快，树脂质量提高，讨论了该催化剂存在下，工艺条件对反应的影响，给出了适宜的催化剂用量。     

Preparation of poly(styrene‐co‐hexylacrylate)/cellulose whiskers nanocomposites via miniemulsion polymerization

A stable aqueous nanocomposite dispersion containing cellulose whiskers and a poly(styrene‐co‐hexylacrylate) matrix was prepared via miniemulsion polymerization. We were able to prepare a stable dispersion with a 20 wt % solid content and a cellulose whiskers content ranging from 1 up to 5 wt % based on polymer content. To avoid particle agglomeration leading to coagulum formation, the addition of a low amount of reactive silane, i.e., methacryloxypropyl triethoxysilane revealed to efficiently stabilize the dispersion. The nanocomposite dispersion was characterized using dynamic light scattering, transmission electron microscopy, and atomic force microscopy. Films obtained by casting followed by water evaporation and particle coalescence were analyzed by differential scanning calorimetry, dynamic mechanical analysis, and tensile testing. At 5 wt % whiskers loading, an enhancement by 500% of the storage modulus above the glass transition was determined. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

涂料用丙烯酸树脂配方设计及其影响因素

叙述了涂料用丙烯酸树脂配方设计中应遵循的原则、影响因素及应注意的问题。     

粉末涂料用GMA型丙烯酸树脂的合成及其固化分析

利用甲基丙烯酸甲酯、甲基丙烯酸缩水甘油酯(GMA)、丙烯酸丁酯进行自由基聚合合成GMA型丙烯酸树脂。研究固化剂十二烷基二元酸用量、固化时间、固化温度、升温速率对涂层性能及固化过程的影响。结果表明树脂与固化剂用量比为10:2,固化条件为160℃固化30min,制备的丙烯酸粉末涂料具有良好的性能。     

High‐performance waterborne coatings based on epoxy‐acrylic‐graft‐copolymer‐modified polyurethane dispersions

Polyurethane dispersions (PUDs) have been an active area of research since the early 1940s because of legislative restrictions on the use of organic solvents in conventional solvent‐based products and also because PUDs exhibit almost the same high performance levels as solvent‐borne polyurethanes. In the present study, properties of conventional waterborne PUDs are modified with epoxy‐acrylic graft copolymer blocks. The epoxy‐acrylic graft copolymers were first modified with ethylene diamine to give amine‐terminated blocks which in turn reacted with isocyanate‐terminated prepolymer (prepolymer mixing process) to give modified PUDs. Several experimental sets were prepared with varying compositions. The experimental sets were also prepared using conventional poly(ethylene glycol) blocks and ethylene diamine chain‐extenders. The physico‐chemical properties and film characteristics of the experimental sets show the dramatic improvement in important mechanical properties of PUDs due to grafting with epoxy‐acrylic copolymer blocks. Copyright © 2004 Society of Chemical Industry     

聚氨酯型不饱和聚酯涂料的研究

通过对反应过程中和涂膜酸值和粘度测定以及涂膜性能测定和红外光谱分析研究了聚氨酯型不饱和聚酯树脂的反应温度、反应时间、醇酸比、TDI用量、饱和酸与不饱和酸配比、交联剂聚苯乙烯用量等对涂料性能的影响。研究表明:反应温度170℃,反应时间3 h,乙二醇、邻苯二甲酸酐与顺丁烯二酸酐物质的量比为1.4:3:7,—NCO与—OH物质的量比为1:1,每15 g树脂中加入交联剂苯乙烯5 g,固化体系0.3 g,填料10 g,可制得物理力学性能较好的聚氨酯型不饱和聚酯涂料,涂膜硬度为5 H,附着力1级,柔韧性0.5 mm,抗冲击性50 cm。     

不饱和聚酯树脂改性研究进展

综述了不饱和聚酯树脂(UPR)改性的研究进展。介绍了收缩率控制机理,低收缩研究发展的4个阶段,低收缩剂LSA的典型代表——聚苯乙烯(PS),聚甲基丙烯酸甲酯(PMMA),聚醋酸乙烯(PVAc),PVAc-PS共聚物。讨论了UPR增韧改性方法,提高分子主链对称性,在分子结构中引入长链醇与长链酸,长链醇包括一缩二乙二醇、二缩三乙二醇及聚乙二醇;长链二元酸如己二酸等。此外还可加入热塑性弹性体,如液体橡胶、液体聚氨酯等以形成互穿网络结构增韧UPR。论述了提高UPR阻燃性的2种途径,即选用本质阻燃性树脂和向UPR中添加阻燃剂。介绍了含卤有机阻燃剂、无机阻燃剂、主链或主链与侧链均含磷的阻燃剂和赋予阻燃性的影响因素。介绍了部分采用可降解的植物纤维——竹纤维制备的UP复合材料和木粉改善UPR的性能。这些方法使不饱和聚酯树脂在低收缩性能、力学性能、阻燃性能等方面得到了改善,扩展了其应用范围。     

油改性涂料用双环戊二烯型不饱和聚酯树脂的合成及应用研究

介绍了油改性双环戊二烯(DCPD)型涂料用不饱和聚酯树脂的合成工艺以及调漆性能测试。试验结果表明,油与多元醇在210～220℃下先醇解,然后与顺酐反应形成半酯,剩余顺酐水解成顺丁烯二酸,然后与DCPD加成,合成的树脂具有优良的空干性;同时油的使用极大地提高了涂膜的柔韧性和抗绿化性,得到的树脂性能上可满足涂料用不饱和聚酯树脂的要求。     

阴极电泳涂料用阳离子丙烯酸树脂的合成与应用研究

通过溶液自由基聚合合成了用于阴极电泳涂料的阳离子丙烯酸树脂,研究了影响树脂水溶性、电沉积效果和涂膜性能的因素,并详细阐述了在应用方面的研究。     

Graft reaction of acrylic acid onto metallocene‐based polyethylene‐octene elastomer

In this study, grafting of acrylic acid (AA) onto metallocene‐based polyethylene‐octene elastomer (POE) was investigated by using benzoyl peroxide as an initiator. Grafted product was characterized by using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X‐ray diffraction spectroscopy, and differential scanning calorimetry (DSC). Both the grafting percentage and the gel yield, at equilibrium, were higher for POE containing lower degree of comonomer content. In all cases, the crosslinking reaction was accompanied by the predominant graft reaction due to the competition of POE macroradical and excited AA. From the result of DSC and X‐ray characterizations, it was found that the change of crystallinity is slight when the gel is removed from POE‐g‐AA copolymers. It was also proven that the effect of gel formation on the properties of the copolymer could be neglected because of the low gel yield. So, the graft method proposed in this article can produce low gel yield copolymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2905–2912, 2002     

不饱和聚酯型人造大理石的力学性能

简述了不饱和聚酯(UPR)型人造大理石的制备工艺。研究了质量比为4∶1的Al(OH)3/Ca(OH)2复合填料用量对不饱和聚酯型人造大理石力学性能的影响,对制得的人造大理石的耐腐蚀性进行了测试,采用光学显微镜观察了试样腐蚀前后的表面形貌。结果表明,在复合填料与UPR质量比为1.86∶1时,弯曲强度、压缩强度达到最大,分别为55.88 MPa和96.04 MPa。甲苯对人造石的腐蚀作用最大,氢氧化钠次之,硫酸腐蚀作用较小,腐蚀介质主要对不饱和树脂聚合物产生腐蚀,从而导致人造石力学性能降低。