Durability prediction of p-urethane clearcoats using infrared p(hoto) a(coustic) s(pectroscopy)

The durability of topcoats is dependent on a large number of factors as polymer composition, stabilization package and the conditions during the weathering process. For obvious reasons prediction of the long-term (5-10 year) durability of coatings is very important. The rate-determining factor for the degradation of PUR coatings is photo-oxidation. The photo-oxidation rate is controlled by the polymer structure but also stabilizers as HALS has a large influence. The prediction of the durability of clearcoats is based on tracing of the photo-oxidation rate and of the HALS longevity during exposure. The photo-oxidation rate is measured using FTIR-PAS. The results show that degradation can be detected much earlier compared with classical methods as gloss loss. Moreover detection of differences between systems after short exposure times as well as prediction of the long-term durability are possible.     

Scratch behavior and material property relationship in polymers

The scratch behaviors of a broad range of polymers are investigated to understand how the material characteristics of a polymer affect the scratch resistance. A constant load scratch test and a progressive load scratch test are chosen for the present study. A scratch model proposed by Hamilton and Goodman is applied to correlate the mechanics and material parameters during the scratch process. An attempt is made to correlate the scratch behavior and basic material properties, such as the Young's modulus, yield stress, and tensile strength. A correlation between the scratch behavior and material surface characteristics, such as the friction coefficient, scratch hardness, and elastic recovery, under the current scratch tests are also made. Scratch subsurface damage in polymers is studied using optical microscopy. It is shown that shear yielding is the main cause of the plastic flow scratch pattern, while tensile tear on the surface and shear‐induced fracture on the subsurface are the main damage mechanisms found in the fracture scratch pattern. The main causes for the susceptibility of thermoplastic polyolefins to scratch damage are discussed. Approaches for making scratch‐resistant polymers are also addressed. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 47–59, 2001     

车用塑料耐刮擦测试方法概述

耐刮擦测试是汽车内外饰塑料零件质量控制的一项重要指标。介绍了耐刮擦测试原理,刮擦头、负载、样品与刮擦头相对运动状态等是决定测试方法的关键技术要素,评价塑料耐刮擦性的方法分为目视法及仪器测量法。综述了五指刮擦法、硬度试验笔刮擦法、网格刮擦法、摩擦色牢度刮擦法及其他刮擦法测试方法,分析和总结了不同测试方法的特点和应用范围。     

Scratch Resistant and Transparent UV-Protective Coating on Polycarbonate

UV-protective coating material has been developed to improve the scratch resistance and transparency of polycarbonate substrates. Acetyl acetone (AcAc) chelated silanes and 3-glycidoxypropyl-trimethoxysilane (GPTMS) modified nano-titania sols were used for the UV-protective hard coating materials by the sol-gel technique. The hybrid network is formed as a result of the controlled hydrolysis and condensation of the MTMS (Methyl Tri Methoxy Silane) and DMDMS (Di Methyl Di Methoxy Silane). Surface modified TiO₂ nano particles were dispersed in sterically stabilized in the hybrid network by the chelating agent. The coatings dried at 130°C after spray coating were shown to have excellent scratch resistance and adhesion and in addition, it roles as efficient UV-protector under UV irradiation. The long time UV test resulted in no crack formation, without loss of adhesion within the test period of 20 weeks.     

High scratch and etch resistance by optimized cross-linking chemistry and density

Target of development in the field of modern automotive clear coats is the combination of high etch and high scratch resistance. For high etch resistance the cross-linking chemistry is the key factor. The property scratch resistance is mainly influenced by the cross-linking density and the flexibility of chains between netpoints. By combining these parameters high etch and scratch resistant clear coats can be formulated. As a representative example an optimized clear coat based on epoxy/acid cross-linking chemistry is discussed. The ways to achieve high cross-linking density are shown.     

Optimization of scratch resistance and mechanical properties in wollastonite‐reinforced polypropylene copolymers

The aim of this research was to establish a balance between scratch resistance and scratch damage visibility in the wollastonite‐filled heterophasic polypropylene copolymers.The influences of various factors including the surface hardness, elasticity, friction coefficient, and combinations thereof on the scratch behavior (scratch resistance and scratch visibility) were elucidated. Using micro‐scale and nano‐scale scratch tests and image analysis techniques, the scratch hardness, scratch depth, and scratch visibility of the composites were characterized.It was found that the introduction of wollastonite in the polypropylene copolymer matrix contributes to ductile fracture behavior because of an induced crystallization alteration. Accordingly, the scratch resistance of reinforced composites revealed an increase as a result of higher stiffness of the wollastonite as well as contribution of new crystalline structure. The addition of siloxane to the composites improved the resistance to surface damage by lowering the surface friction coefficient originated from enhanced chain mobility. Simultaneous addition of high density polyethylene and siloxane induced a significant influence on the resistance to the scratch damage. Copyright © 2015 John Wiley & Sons, Ltd.     

改性紫外光固化聚硅氧烷的合成及其感光性能

改性紫外光固化聚硅氧烷的合成及其感光性能;紫外光固化;聚硅氧烷;光敏性能     

Synthesis of a Novel UV Curable Aqueous Dispersion Polyurethane PDHA-PEDA-PU and the Properties of Cured Film

Because of the merits in environmental protection and lower energy consumption, ultraviolet (UV) curable coatings have been gained more and more attention and speedy development in the past decades. UV curable waterborne polyurethane has been employed pop…     

光/潮气双重固化聚氨酯涂层的制备及性能研究

以甲苯-2,4-二异氰酸酯(TDI)和二乙醇胺(DEOA)为原料一步法合成了超支化聚氨酯,对其改性制备了光固化超支化聚氨酯丙烯酸酯(HPUA)和一系列双重固化(UV/潮气)超支化聚氨酯丙烯酸酯(DHPUA),使用傅立叶红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)以及凝胶色谱(GPC)对其分子结构进行了表征.并以其为预聚物制备光固化涂层,通过对双重固化涂层的表面形貌、热性能和物理性能的研究,结果表明,超支化双重固化涂层经过潮气固化后,涂层表面的粗糙度随着树脂中硅氧烷端基的含量的增加先下降后上升;超支化双重固化涂层的物理性能和热稳定性都随着树脂中硅氧烷端基的含量的增加而提升.     

聚甲氧基硅氧烷及其功能化产物研究Ⅰ.制备

通过正硅酸甲酯(TMOS)在酸性条件下的部分水解缩合反应制备了不同分子量的聚甲氧基硅氧烷(PMOS)，详细讨论了水与TMOS的摩尔比(r)对PMOS结构和性能的影响。用丙烯酸-2-羟乙酯(HEA)通过酯交换反应使PMOS的部分甲氧基变为丙烯酰氧乙氧基，从而得到可进行热聚合或光聚合反应的功能化聚甲氧基硅氧烷PAMOS，讨论了影响酯交换反应的各种因素。     

聚甲氧基硅氧烷及其功能化产物研究Ⅱ.分子结构表征

通过正硅酸甲酯(TMOS)的水解缩合反应制备了聚甲氧基硅氧烷(PMOS)，其分子式可表示为：[SiOa(OH)b(OCH3)c]n。用丙烯酸-2-羟乙酯(HEA)进行酯交换后，制的功能化产物聚丙烯酰氧基甲基硅氧：烷(PAMOS)，其分子式可表示为：[SiOd(OH)c(OCH3)f(OCH2CH2OCOCH=CH2)g]k。通过二氧化硅分析、红外光谱(FTIR)、凝胶渗透色谱(GPC)等方法确定了分子式中a、b、c、n及d、e、f、g、k的值，是一种比较方便、快捷且准确的方法。     

超支化树脂改性UV固化粉末涂料

本文将超支化树脂(HBP)与UV固化粉末涂料相结合,研究了超支化树脂对该涂料的树脂体系玻璃化温度、流变性能及涂膜各项物理性能的影响.结果表明:添加改性与未改性超支化树脂都能降低树脂体系的玻璃化温度,改性超支化树脂不影响体系的流变性能及涂膜性能,未改性超支化树脂可以降低体系粘度但使涂膜性能变差.     

UV光固化热敏记录层机理的研究

以光固化丙烯酸酯树脂作为基体,硬脂酸、聚乙二醇硬脂酸酯等为添加物,制备了一种可逆热透明成像材料的UV光固化热敏记录层.利用DSC仪、偏光显微镜以及X射线衍射仪研究了添加的硬脂酸和聚乙二醇硬脂酸酯对UV光固化热敏层的作用机理.研究结果表明,硬脂酸和聚乙二醇硬脂酸酯结晶态与无定形态之间的转变是UV光固化热敏层发生白色浑浊态与透明态转变的直接原因,且两者的共同作用扩大了UV光固化热敏层的显透温度范围.另外,利用热分析仪对热塑性热敏层和光固化热敏层的耐热性作了比较.结果表明,UV光固化热敏层在升温过程中的热损失较热塑性的热敏层有明显降低.     

Preparation and thermal properties of a novel UV‐cured star polyurethane acrylate coating

A novel star polyurethane acrylate (SPUA) used for UV‐curable coating was prepared from 2,4‐toluene diisocyanate, 2‐hydroxyethyl arcylate, and hexakis(2‐hydroxyethyl)melamine, and characterized using FTIR, ¹H‐NMR, and elemental analysis. Its UV curing behaviors investigated via FTIR clearly indicated that this monomer could be cured rapidly at air atmosphere. The conversion of the unsaturated bond of the cured monomer sample is near to 72% after exposed under UV light for 40 sec. The hardness, flexibility, and mechanical properties of the cured film were also investigated. The thermal stability of the cured film was studied using thermogravimetric analysis (TGA) and real time Fourier transform infrared (RTFTIR). Results showed that this oligomer has some superior properties and can be used for UV curing coating. Copyright © 2007 John Wiley & Sons, Ltd.     

紫外光固化耐磨涂料的进展

综述了紫外光固化耐磨涂料的进展情况 ,着重介绍了溶胶 -凝胶法制备紫外光固化耐磨杂化涂料的研究进展。     

光固化环氧丙烯酸酯/SiO2杂化材料的研究

用FTIR、SEM、DSC和TGA表征了光固化环氧丙烯酸酯／SiO2杂化材料[(EA-TMSPM)／SiO2]，研究了盐酸、γ-甲基丙烯酰氧丙基三甲氧基硅烷(TMSPM)和无机物浓度对(EA-TMSPM)／SiO2结构与性能的影响。结果表明，无机物浓度高的(EA-TMSPM)／SiO2杂化体系中SiO2粒子尺寸略大于无机物浓度低的体系；盐酸和无机物浓度的增加，都可以增强杂化材料的耐磨性。     

光固化粉末涂料中两种复合光引发剂表观量子效率的测定

采用动力学分析方法,测定了几种不同配比光固化粉末涂料引发剂的紫外吸收光谱,并由此进行了量子效率的测定.据此可比较不同引发体系的引发效率.文中详细介绍了计算量子效率的过程.结果表明,不同的引发剂体系不同的配比,其引发效率可相差2—3倍.     

UV固化丙烯酸酯化有机硅及杂化材料的研究与应用

丙烯酸酯化有机硅及杂化材料因兼具有机硅材料的优异性能和光固化的高效、节能及环保等特点而得到广泛的应用。文章综述了光敏性丙烯酸酯化有机硅单体的种类、结构特点及其制备方法,分析了紫外光（UV）固化后聚合物及其杂化材料的性能,介绍了它们的研究与应用现状及其发展前景。     

UV Curable Hard Transparent Hybrid Coating Materials on Polycarbonate Prepared by the Sol-Gel Method

UV curable, hard, transparent inorganic/organic composites with covalent links between the inorganic and the organic networks were prepared by the sol-gel method. These hybrid coating materials were synthesized using a commercially available, acrylate end-capped polyester or polyurethane oligomeric resin (EBC80, EBC284), hexanedioldiacrylate (HDDA) as a reactive solvent, 3-(trimethoxysilyl)propoxymethacrylate (TMSPM) as a coupling agent between the organic and inorganic phase, and a metal alkoxide, tetraethylorthosilicate (TEOS). The materials were applied on primer or oxygen plasma pretreated polycarbonate sheets and UV cured, followed by a thermal treatment to give a transparent coating with a good adhesion and abrasion resistance. The high transmission and the thermogravimetric behavior indicate the presence of a nanoscale hybrid composite, as is confirmed by SAXS and TEM measurements. In a Taber Abrasion Test, uncoated polycarbonate sheets exhibit a 48% decrease in light transmittance at 600 nm after 300 wear cycles, whereas the EBC80 hybrid coating system containing 9 wt% SiO₂ (EBC80/25Si) shows only 28% decrease in light transmittance. A maximal improvement of the abrasion resistance is achieved when 23 wt% SiO₂ is incorporated (EBC80/60Si, EBC284/60Si) with only 20% decrease in light transmittance. The abrasion resistance of glass is not yet encountered. For optimal results, it is essential that the rate of condensation of the silanol groups is sufficiently high to form a dense three-dimensional network.     

Evaluation of the scratch resistance with nano- and multiple scratching methods

The scratch resistance of automotive clear coats was investigated by a single and multi scratch test procedure. New data characteristic for the reflow capability, the scratch hardness and the lateral scratch resistance were generated and evaluated. A correlation between single and multi scratch data was established.