Preparation and properties of acrylic melamine hard coating

Melamine resin polymers exhibit high transmittance, high pencil hardness, and high refractive index. However, high temperatures and long reaction times are required to obtain the desired condensation products. In this study, acrylic‐modified melamine resins were synthesized that were cured by irradiation with ultraviolet (UV) light. The synthesized acrylic‐modified melamine resins could be cured rapidly due to the radical reaction of the acrylic groups and retained high transparency and high refractive index as features of the melamine resin polymers. The polymerized film by UV curing had low shrinkage and high refractive index. Compared with general multifunctional moiety‐type acrylic monomers such as pentaerythritol triacrylate and dipentaerythritol hexaacrylate, the acrylic‐modified melamine resins had the same degree of hardness. In addition, flexibility, a feature of the urethane moiety, was imparted to the polymer by the reaction of residual hydroxyl groups with isocyanate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 000: 000–000, 2010     

Viscoelastic properties and coating performance of acrylic copolymers crosslinked with melamine resin

For 8 carboxy and hydroxy functional acrylic copolymers crosslinked with melamine resin, glass transition temperature (T_g), molecular weight of chain segments between crosslinked point (M_c), and polymer-solvent interaction parameters (χ_g ) were determined by dynamic mechanical measurements and swelling measurements. T_g increases and M_c decreases with the increase of hydroxyl value and the molecular weight of acrylic copolymers. T_g decreases and M_c increases with the increase of alkyl chain length of acrylate in acrylic copolymers. The film hardness, T_g and polarity of methyl methacrylate (MMA) containing acrylic-melamine-cured films are higher than those of styrene-containing acrylic-melamine-cured films, but both films are almost the same in the degree of crosslinking (maximum loss tangent, tan δ_max, and M_c). T_g increases and M_c decreases with the increase of melamine resin content for acrylic-melamine coatings. The cured film consists of the acrylic-melamine segments and the melamine-melamine segments at crosslinking points. The carboxy group enhances the crosslinking reactions at low temperatures. All films crosslinked have single glass transition temperatures and broad damping peaks, which show good compatibility. The values of χ_g of acrylic copolymer-melamine films in polar and nonpolar solvents depend on the polarity of acrylic composition and the degree of crosslinking. χ_g values of carboxy functional acrylic-melamine film in any solvents are smaller than that of carboxy and hydroxy functional acrylic-melamine film. χ_g values of MMA-containing acrylic-melamine film in polar solvents are smaller than those of styrene-containing acrylic-melamine film, but χ_g values of MMA-containing acrylic-melamine film in nonpolar solvents are larger than those of styrene-containing acrylic-melamine film. χ_g values of acrylic-melamine film in polar and nonpolar solvents increase with the increase of alkyl chain length of acrylate. The χ_g values of acrylic-melamine coatings in toluene are less than 0.3 and smaller than those of alkyd coatings.     

Viscoelastic properties and coating performance of water-soluble acrylic copolymers crosslinked with melamine resin

Acrylic copolymers with different amounts of carboxyl and hydroxyl groups for obtaining practical performance of melamine-cured acrylic coatings was investigated. Property testing results indicated that glass transition temperature (T_g) and shear modulus increased, and molecular weight between crosslinks (M_c) decreased with the increase of hydroxyl and carboxyl number in the acrylic copolymers. The degree of crosslinks influenced the resistance to solvent and chemicals at a lower baking temperature. Compared with acrylic acid, itaconic acid as a carboxyl monomer was more effective in inducing a lower baking schedule. The water-soluble acrylic copolymer, which is neutralized with triethylamine, consists of 20 wt % methylmethacrylate, 55 wt % buthylacrylate, 15 wt % hydroxyethyl methacrylate, and 10 wt % itaconic acid. The copolymer showed higher crosslinks when cured with methoxymethyl melamine formaldehyde resin under a relatively lower baking schedule at 135°C for 30 min. It also has excellent solvent and chemical resistance. This coating film has a T_g value of 39°C, modulus of 2 × 10⁸ dyne/cm² in the rubbery state, and M_c value of 464. Also the acrylic copolymer films with M_c < 900 have good properties for solvent, acid, and alkali resistance. © 1995 John Wiley & Sons, Inc.     

高固体分涂料用含羟基星形丙烯酸酯树脂的制备及性能

以占单体物质的量0.01%的低铜盐用量催化剂体系进行电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP), 制备了丙烯酸丁酯、甲基丙烯酸甲酯和丙烯酸羟丙酯为单体的线形和六臂星形共聚物。采用折光指数-激光-黏度三检测联用GPC, ¹H NMR和DSC对聚合物的分子结构、共聚组成和玻璃化转变行为进行了研究。将聚合物配制成涂料用树脂溶液, 流变行为研究表明星形聚合物溶液黏度最低。在高固含量时, 星形聚合物降低黏度的优势更明显。在适合喷涂施工的黏度下, 六臂星形共聚物比普通自由基聚合得到的商品化丙烯酸酯树脂的固含量可提高10%。采用异氰酸酯固化剂固化得到的漆膜性能测试表明, 星形聚合物对应清漆的表干时间很短, 同时力学性能达到良好水平。     

Preparation and characterization of weather resistant silicone/acrylic resin coatings

Preparation and characterization of weather resistant silicone/acrylic resin coatings were conducted. In order to prepare these coatings, a silicone/acrylic resin (KLD) was first prepared by an addition polymerization reaction of monomers, including n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and 3-methacryloxypropyltrimethoxysilane (MPTS). In the preparation of the silicone/acrylic resin, T_g of the acrylic copolymer was fixed at 40°C and the contents of MPTS were varied to be 10, 20, and 30 wt%. The weather resistant silicone/acrylic resin coatings were then prepared by blending the synthesized silicone/acrylic resin and TiO₂. The viscosity of the synthesized resin decreased with the content of MPTS, whereas the thermal stability at high temperature increased. The prepared coatings exhibited excellent adhesion to various substrates, and various physical properties of the coatings were satisfactory. The weatherability of the coatings was tested three ways: outdoor exposure test, Weather-Ometer (WOM), and QUV accelerated weatherability tester (QUV). The gloss retention, yellowness index difference, color difference, and lightness index difference were improved at high MPTS concentration. The coatings containing 30 wt% MPTS have especially good weather properties. Dept. of Chem. Eng., Yongin 449-728, Korea. Ansan 425-110, Korea.     

带环氧基丙烯酸树脂改性环氧树脂防腐涂料的性能

利用自由基聚合法合成了带环氧基丙烯酸树脂,并对其结构进行了表征,研究了引发剂和链转移剂用量对带环氧基丙烯酸树脂黏度的影响。将带环氧基丙烯酸树脂与环氧树脂按1∶9的质量比混合,复配防腐颜料及填料制备改性环氧树脂防腐涂料,并测定了其层间附着力和防腐蚀性能。结果表明:单体发生完全聚合,且聚合物带环氧基;随着引发剂和链转移剂用量的增加,带环氧基丙烯酸树脂的黏度下降;与纯环氧树脂防腐涂料相比,改性环氧树脂防腐涂料的层间附着力更高,n(MMA)∶n(BA)∶n(GMA)为6.00∶3.00∶0.475和6.00∶3.00∶1.000的涂料配方耐盐雾性和电化学阻抗更优。     

Thermal stability and dynamic mechanical behavior of acrylic resin and acrylic melamine coatings

Acrylic polyols of different hydroxyl numbers consisting of hydroxy ethyl methacrylate, methyl methacrylate, butyl acrylate, and styrene were prepared by free‐radical solution as well as suspension polymerization techniques in the presence of benzoyl peroxide initiator. These polyols were crosslinked with butoxy methyl melamine at a ratio of 85 : 15 in the presence of acid catalyst. The thermal stability of polyols and their corresponding crosslinked films was studied by thermogravimetric (TG) technique. The Broido and Coats–Redfern methods were used to calculate the activation energy of thermal decomposition from standard TG curves. Dynamic mechanical thermal analysis was used to study the dynamic mechanical properties and determination of glass‐transition temperature of acrylic/melamine crosslinked films. The results indicate that the thermal stability of polyols and crosslinked films strongly depends on the hydroxyl number of the acrylic polyols. It was found that acrylic polyols synthesized by suspension polymerization methods upon crosslinking yield more thermally stable and flexible films than polyols prepared by solution polymerization methods. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 27–34, 2004     

有机硅改性丙烯酸树脂的合成工艺

采用乙烯基三乙氧基硅烷和八甲基环四硅氧烷为改性剂与丙烯酸单体乳液聚合,制得聚合工艺稳定、耐水性能和耐擦洗性能优异的树脂,该树脂能室温交联固化,适用于高档外墙涂料和防水要求较高的地方。并讨论了有机硅单体类型、用量、反应温度和调节剂等因素与树脂性能的关系。     

自交联型丙烯酸酯树脂纸塑复合胶的制备与性能

以丙烯酸丁酯(BA)、酪酸乙烯酯(VAC)为主要原料,适当引入丙烯酸(AA)、丙烯酸羟丙酯(HPA)等活性功能单体,在半连续加料方式下通过种子乳液聚合法制备乳液型纸塑复合胶。探讨了单体选择及配比和功能单体、引发剂与乳化剂用量对乳胶性能的影响。最后对松香增粘作用进行了试验研究。     

硅铝复合树脂的制备及其涂层性能

以硅溶胶和甲基三乙氧基硅烷(MTES)为前驱体,乙酸为催化剂,添加Al2O3纳米粒子,经水解-缩聚合成硅铝复合树脂,再加热固化成膜得到硅铝复合涂层,研究了所得涂层的结构与性能。硅铝复合涂层为Si—O交替形成的四元环体型结构。m(Al2O3)/m(MTES)为0.010时制备的硅铝复合涂层的力学性能最佳,铅笔硬度为8 H,附着力为0级,透光率达92.5%,硅铝复合涂层中Si—CH3的起始分解温度为500℃,耐热性能明显提高。     

新型改性醇酸树脂涂料的制备及性能研究

采用脂肪酸一步法合成了端羟基醇酸树脂,并给出了甲苯二异氰酸酯(TDI)改性醇酸树脂的制备工艺。从树脂涂料的固含量、表面干燥时间、硬度等方面考察了n(—NCO)∶n(—OH)、二羟甲基丙酸(DMPA)和三乙胺的用量、初期及中期聚合温度的影响,并对其进行了红外表征。实验结果表明:n(—NCO)∶n(—OH)=1.8,w(DMPA)≈5%,三乙胺在改性反应前加入,用量为1.7g(每20g样品),初期聚合温度30℃、中期聚合温度80~85℃时,制得的涂料综合性能优异。     

阴极电泳涂料用高硬度丙烯酸酯树脂的研制

以甲基丙烯酸丁酯(BMA)和甲基丙烯酸甲酯(MMA)为主要硬单体、N-羟甲基丙烯酰胺(NMA)和甲基丙烯酸羟乙酯(HEMA)为自交联单体,加入封闭型异氰酸酯固化剂,合成了一种阴极电泳涂料用丙烯酸酯树脂。研究了不同质量比的单体、自交联单体以及固化剂与树脂的不同配比对涂料涂膜性能的影响。结果发现,BMA和MMA的用量分别为单体总量的30%和16%,NMA和HEMA以质量比为3:15进行自交联,加入与基料树脂质量比为1:3的固化剂,所得的涂膜外观平整光亮,性能优良:硬度达到5H,附着力1级,抗冲击强度35kg·cm,耐碱性实验(在0.1mol/LNaOH溶液中)240h,耐酸性实验(在0.1mol/LH2SO4溶液中)72h。     

聚丙烯酸酯无皂乳液的构建及对水性油墨性能的影响

以丙烯酸（AA）、丙烯酸丁酯（BA）、甲基丙烯酸甲酯（MMA）、丙烯酸羟丙酯（HPA）、2-甲基丙烯酸羟乙酯（HEMA）、乙烯基三异丙氧基硅烷（A-173）为单体,过氧化苯甲酰（BPO）、过氧化苯甲酸叔丁酯（TBPB）为引发剂,合成了丙烯酸酯大分子乳化剂,再通过无皂乳液聚合法合成了聚丙烯酸酯无皂乳液,将其与颜料等混合制备了水性油墨。采用FTIR、DSC、TEM、SEM对聚合物的结构及性能进行了表征,考察了不同BPO用量对丙烯酸酯大分子乳化剂的影响,不同AA添加量对乳液及水性油墨的影响。结果表明：当BPO用量为单体总质量的4.18%时,丙烯酸酯大分子乳化剂具有最低表面张力40.43 mN/m;当AA添加量为单体总质量的1.00%时,聚丙烯酸酯无皂乳液具有合格的储存稳定性,乳胶膜拉伸强度可达5.00MPa,断裂伸长率为200%,玻璃化转变温度为18.5℃,所制备的水性油墨黏度为23.79 mPa·s,附着牢度90.75%,耐摩擦性4.5级。     

有机硅改性丙烯酸酯聚合物的制备方法

从物理共混和化学改性两个方面综述了有机硅改性丙烯酸酯聚合物的方法,主要对缩聚法、自由基聚合法、硅氢加成法、互穿网络法进行了介绍,并对有机硅改性丙烯酸酯乳液的发展前景作了展望。     

氟硅烷改性水性丙烯酸二级分散体的制备与涂层性能

将1,1,3,3-四甲基-1,3-二乙烯硅氮烷(DVDZ)和甲基丙烯酸六氟丁酯(EINECS)进行Micheal加成反应,合成2,2,3,4,4,4-六氟丁基-3-(二(二甲基(乙烯基)硅基)氨基)-2-甲基丙酸酯(DVE)功能有机氟硅单体,与甲基丙烯酸甲酯(MMA)、甲基丙烯酸羟乙酯(HEMA)等单体混合,以偶氮二异丁腈(AIBN)为引发剂,异丙醇(IPA)为溶剂,合成氟硅烷改性水性丙烯酸二级分散体。然后,将其与异氰酸酯固化剂混合,制备了双组分水性聚氨酯(2K-WPU)涂膜。通过FTIR、1HNMR、TG、SEM、XPS对DVE和2K-WPU进行表征和检测,结果表明:随着DVE质量分数的增加,丙烯酸二级分散体的粒径增大,黏度降低,涂膜的耐水性增强,铅笔硬度和附着力减弱。当DVE质量分数为6%时,吸水率为8.2%,接触角为91.5?,热失重10%和50%时的温度分别为220.9和438.5℃,涂膜耐热、耐水和耐酸碱等性能均有提升。     

透明氧化锌/有机硅纳米复合材料的制备与性能

采用乙烯基三乙氧基硅烷（A 151）对自制的不同粒径的纳米Zn O颗粒进行改性,然后与含氢硅油化学接枝制得Zn O接枝含氢硅油（Zn O-PMHS）,最后采用氢化硅烷化法,以接枝物为交联剂,在铂催化剂作用下制备了一种发光二极管封装用透明Zn O/有机硅复合材料,考察了纳米Zn O颗粒种类及用量对复合材料物理机械性能及光学性能的影响,并表征了复合材料的微观相态。结果表明,自制的纳米Zn O颗粒平均粒径为295,350,415 nm,经A 151改性后,粒径分布变窄,粒径减小;纳米Zn O颗粒的加入提高了纳米复合材料的拉伸强度,但随着纳米Zn O颗粒粒径的增大,复合材料的拉伸强度呈下降趋势;改性纳米Zn O颗粒对复合材料拉伸性能和透光率的改善幅度优于未改性纳米Zn O颗粒,当改性纳米Zn O颗粒质量分数为0.06%时,复合材料的物理机械性能较佳,对于300 nm以下紫外线的屏蔽效率超过90%,耐紫外老化性较纯有机硅材料有明显提高;A 151改性Zn O均匀接枝到有机硅聚合物链中,复合材料固化后表面平整性较好,但出现应力集中现象。     

有机硅硬质涂料的制备

以甲基三乙氧基硅烷和正硅酸乙酯为主要原料，经水解缩合，制得低n(R)／n(Si)值的硅树脂；添加适当的溶剂、固化剂和改性剂等助剂，制得有机硅硬质涂料。讨论了原料配比、溶剂及各种助剂对有机硅硬质涂料性能的影响。结果表明，硅树脂的n(R)／n(Si)值选择0、85，以甲醇／乙醇／异丙醇／乙二醇甲醚为复合溶剂、氨基树脂为耐碱改性剂、三乙酰丙酮铝为固化剂时，制成的有机硅硬质涂料贮存期超过6个月，固化速度快，涂膜硬度高达6H，对有机玻璃的附着力为1级，透光度93．6％，耐碱性良好。     

Preparation and characterization of silicone resin nanocomposite containing CdSe/ZnS quantum dots

We report the preparation of the core/shell cadmium selenide/Zinc sulfide quantum dots (CdSe/ZnS QDs)‐silicone resin nanocomposite through the solution‐mixing method, followed by thermal hydrosilylation. After dispersing QDs into Dow Corning two‐component silicone resins (OE6630A and OE6630B at 1:4 mixing ratio by weight), the resins were cured at 150°C for 1.5 h to produce QD‐silicone resin nanocomposites. The curing behavior of the silicone resins resulting from the thermal hydrosilylation was studied using differential scanning calorimetry (DSC). The properties of the QD‐silicone resin nanocomposites were investigated by ultraviolet–visible (UV–vis), fluorescence, confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA) measurements. The QDs that contain trioctylamine (TOA) as the original ligand can poison the Pt catalyst in the resins and inhibit the curing process by increasing the exothermic peak temperature, at which a lower heat of hydrosilylation is observed. Incorporating a small amount of CdSe/ZnS QDs (0.1 wt%) can greatly improve the thermal stability of the silicone resins. Moreover, CdSe/ZnS QDs tend to form clusters that are relatively homogeneously distributed in a cured silicone resin, offering good optical properties of 11.2 lm W⁻¹ luminous efficiency and 14.6% photoluminescence conversion efficiency (PCE) in light emitting device (LED) test. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Coemulsion and electrodeposition properties of mixtures of cationic epoxy resin and cationic acrylic resin containing blocked-isocyanate groups

2-Ethylhexanol–half-blocked-toluene diisocyanate (2EH-half-blocked TDI) was first reacted with 2-hydroxyethyl methacrylate (HEMA) to prepare HEMA–TDI–2EH monomer containing blocked-isocyanate groups. This monomer was reacted with butyl acrylate, styrene, and N,N-dimethylaminoethyl methacrylate to prepare an acrylic copolymer III ′ containing blocked-isocyanate groups and tertiary amine groups. The acrylic copolymer III ′ can be mixed with an epoxy–amine adduct IV ′, acetic acid, and deionized (D.I.) water to from an electrodepositable coemulsion. The electrophoretic codeposition of the coemulsion and physical and chemical properties of the codeposited film were investigated. The resin composition of film deposited from coemulsion was determined by Fourier transform infrared (FTIR) quantitative analysis to study the coemulsion and electrophoretic codeposition behavior. The applicability of this two-component coemulsion in primer–surface (pricer) electrodepositable paint was also discussed. The results indicate that the deposition yield of cationic acrylic copolymer III is greater than that of cationic epoxy resin IV , i.e., the deposition velocity of III is faster than that of IV . However, resins III and IV can be well codispersed in D.I. water to form stable coemulsion; thus, the resin composition of deposited is almost equal to the resin composition. Moreover, the throwing power of coemulsion is almost equal to that of IV emulsion but greater than that of III emulsion. The optimum resin compositions of coemulsions for obtaining better gel content of deposited films are between 0.65 and 0.8 ( III/III + IV , by weight). © 1994 John Wiley & Sons, Inc.     

肠溶型药物包衣用丙烯酸树脂的制备工艺

采用乳液聚合法制备肠溶型药物包衣用丙烯酸树脂,采用甲基丙烯酸与甲基丙烯酸甲酯作为共聚单体、过硫酸钾作为引发剂、十二烷基硫酸钠及OP-10复配作为乳化剂、苯乙烯的二聚体作为分子量调节剂、碳酸氢钠作为pH值调节剂,考察了乳化剂配比及用量、引发剂及分子量调节剂的用量、反应温度、加料方式、相比等因素的影响,最终确定了实验制备药物包衣用丙烯酸树脂的最佳条件。利用乌氏粘度计测定其相对分子量,并作了红外光谱测试,结果表明,乳液符合国家药典要求。该制备过程避免了有机溶剂的使用,有明显的经济和环保效益。