聚氯代对二甲苯表面原位引发接枝聚合提升膜表面能的研究

通过钠-萘络合物的处理,在聚氯代对二甲苯膜表面形成自由基,通过表面自由基原位引发甲基丙烯酸甲酯聚合,在薄膜表面引入极性基团以提高膜表面黏结性能。利用红外光谱、X射线衍射和显微镜对接枝改性后薄膜的化学组成和表面形貌进行了表征,运用聚合物膜表面接触角的变化表征了其改性效果。结果表明,甲基丙烯酸甲酯单体由聚氯代对二甲苯膜表面自由基引发,从Cl位置接入,接枝链以共价键的形式与聚氯代对二甲苯膜连接;接枝改性后聚氯代对二甲苯膜表面出现-C=O的特征吸收峰,-CH2的吸收峰随接枝时间的延长而逐渐增大;接枝后薄膜的表面能由28.6 mJ/m2提高到54.1 mJ/m2,拉伸强度由150.5 kPa提高到222.5 kPa。     

一种黑色环氧聚氨酯阴极电泳漆

有机硅氧烷树脂乳液组合物及由其涂覆的物件；在大面积复杂形状底材上形成有机硅树脂涂层的方法；通过涂覆聚硅氯烷溶液在贵重金表面形成持久保护层的制备方法；光学设备保护层形成材料用热固性树脂组合物；[编者按]     

聚一氯对二甲苯涂层材料防护性能的研究

聚对二甲基苯类(Parylene)涂层是一种具有优异防护性的高分子材料。本文以一氯对二甲基苯二聚体为原料,利用真空气相沉积法制备了聚一氯对二甲苯涂层(Parylene C)。利用接触角测定仪测得Parylene C涂层与H_2O的接触角为114.04°,表明Parylene C涂层有着较优异的防水特性。以涂覆Parylene C涂层的铜片为工作电极,通过对电极的电化学交流阻抗谱(EIS)、开路电位(OCP)和塔菲尔(Tafel)曲线对涂层的电化学性能进行分析,结果表明Cl元素的存在有效地的阻止氧气和其它腐蚀性气体的通过,使得Parylene C涂层对铜片具有优异的防腐蚀性能,腐蚀电流密度降低到了10~(-7.5)A/cm~(-2)。     

多孔聚氯代对二甲苯膜的表面润湿性和阻隔性能研究

聚氯代对二甲苯膜(PPXC膜)表面疏水性较低,同时其水蒸气阻隔性能还有待进一步提高。通过在其表面引入不同质量分数的热固性聚二甲基硅氧烷(PDMS)涂层,调控PDMS热固化环境的相对湿度,从而调控涂层表面物理形貌,提高PPXC膜疏水性能和水蒸气阻隔性能。采用水滴接触角测试仪(WCA)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和水蒸气透过率测试仪(WVTR)对PPXC膜表面的润湿性、化学组成、物理结构和水蒸气阻隔性能进行表征。结果表明,PPXC膜表面能够形成大面积的均匀多孔结构,其疏水性得到明显提高,表面接触角可以从86°提高到142°,同时其水蒸气阻隔性能也得到进一步提高,水蒸气透过率从5.26 g/(m2·d)下降为1.58 g/(m2·d)。     

阴极电泳涂料的研究进展

阴极电泳涂装具有涂料利用率高、容易实现涂装自动化、环境污染小、涂膜厚度均匀、耐腐蚀性强、泳透率高、适于涂装形状复杂的工件等优点,在汽车工业底漆中获得了广泛应用.本文对阴极电泳涂装的发展历史及发展动向作了详细的介绍.     

电绝缘涂料

D104210 TSK-96绝缘漆的性能及应用[刊」l汤成荣等11环氧树脂应用技术一2000,17(2)一17-25,280104211半导体元件表面耐热绝缘涂膜的形成:」P200于281969旧本专利公开1旧本:Sumitomo BakelitC Co.,Ltd.(Yamamoto,Kagehisa等)一000.10.10一17页一199919053840电绝缘涂料2001年(1999.3.31):IPC C09D179/08 题述涂膜包括含硅氧烷的聚酸亚胺涂层和聚酞胺涂层,其制备方法如下:在半导体元件表面涂覆第一层聚酞胺酸涂层,预烘烤,再涂覆第二层聚酸胺酸涂层,加热。例如,将3,3’,4,4’一氧代一二邻苯二甲酸二醉1,2,3一二(3一氨基苯氧基)苯0.gmol…     

PC膜表面漆膜紫外光固化漆的工艺优化研究

具有"5E"特点的紫外光固化技术在纸张、木材、塑料、金属等基材的涂装防护领域均有广泛应用。将其涂覆于聚氯代对二甲苯膜(PC膜)表面,提高PC膜耐冲击强度的同时,与其他材料的粘结强度也有了明显改善。针对PC膜表面紫外光固化漆(UVCC-IM-1)工艺参数,探究了不同含量溶剂乙酸乙酯对涂层固化程度的影响;并对不同烘烤温度下漆膜稀释剂的失重情况进行分析,结果表明,最佳烘烤温度为80℃,50μm厚度漆膜烘烤6~8 min时,溶剂完全挥发,膜层得以完全固化;除此之外,同时还研究了漆膜厚度、光密度与辐照时间的关系。结果光密度为8.2 m W/cm~2、厚度为30~50μm漆膜的固化时间为3.1~5.4 s。     

施工工艺

形成多层涂膜的方法,粉末涂料及形成纹理涂层的方法,下层部件中具有复杂形状工件的电沉积涂装,形成多层亮涂膜的方法     

聚对二甲苯的制备及其应用研究进展

聚对二甲苯是一种性能优异的涂层材料。文中主要对聚对二甲苯的制备方法、成膜机理、聚对二甲苯薄膜的性能及其应用领域进行了综述,指出其发展中存在的问题,并对其发展前景进行了展望。     

施工工艺

通过在聚集材料中加入荧光标记物监测热喷涂涂装过程的方法；以聚液晶功能涂料涂装的底材及涂装的玻璃底材；制造过程中的家具及地板表面密封方法；具有着色涂层和含大量填料的清漆层的涂覆金属板及其制品；金属涂料组合物、涂膜的形成方法及涂覆的产品；[编者按]     

The influence of thermal history on structure and water transport in Parylene C coatings

Poly(monochloro-p-xylylene) (Parylene C) coatings are commonly used in a number of applications due to their robust properties and unique ability to be deposited directly from the vapor phase. Recently, Parylene C has been used in new medical devices, where an accurate assessment and understanding of liquid transport and its relationship to the polymer structure is critical in design and evaluation. In this study, the diffusion of liquid water in Parylene C coatings was examined as a function of the thermal history with in situ time-resolved Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy, while the polymer structure was investigated with in situ X-ray scattering. Anomalous transport behavior was observed, where dynamic infrared spectra provide evidence of water diffusion and water-induced polymer relaxation occurring on similar time scales. Both of these phenomena were quantified and regressed to a diffusion-relaxation model to determine the diffusion coefficient and polymer relaxation time constant. After thermal treatment of the Parylene C coating, the water diffusivity reduced by 2-fold, which can be attributed to the increase in crystallinity and the evolution of a new crystalline phase in Parylene C.     

Engineering the surface and interface of Parylene C coatings by low-temperature plasmas

There is a need for the development of environmentally benign processes by which to protect aluminum alloys from corrosion. Vacuum-deposited Parylene C conformal coating is a very good candidate to provide such protection due to its excellent bulk properties: its moisture barrier, high mechanical strength and thermal stability. However, its poor adhesion to most smooth or non-porous substrates has restricted its application. In this study, low-temperature plasma deposition and treatment has proved to be a powerful approach to engineer the surface and interface of Parylene C coatings. After applying a special plasma polymer coating, which acts as an inter-layer to provide good adhesion to the substrate as well as to the subsequent primer, an excellent adhesion of Parylene C coating to a smooth 7075-T6 aluminum alloy has been achieved. After the surface has been functionalized by plasma treatment, the naturally hydrophobic Parylene polymer became paintable with both solventborne and waterborne spray primers.     

Interfacial factors in corrosion protection: an EIS study of model systems

The effects of the liquid–coating interface and coating–metal interfaces on corrosion protection of a coated aluminum sheet (Alclad 7075-T6) were investigated using electrochemical impedance spectroscopy (EIS) of selected model systems. Parylene C was deposited on a solvent-cleaned aluminum sheet to prepare the coated aluminum sheet. Parylene C does not adhere well to most smooth surfaces: a freestanding film can easily be peeled off the substrate, although it does not peel off by itself during EIS measurements. When an ultra-thin layer of plasma polymer (ca. 50 nm) is deposited on the substrate, however, Parylene C adheres very strongly to the sheet. The top surface of Parylene C coating was modified via deposition of an ultra-thin layer of either a very hydrophobic or a very hydrophilic plasma polymer. The EIS Bode plot for the first run showed a typical good barrier coating regardless of the nature of the two interfaces under consideration. However, it was found that the impedance value in the lower frequency region decreases with increased immersion time, and the time-dependent change is greatly influenced by the nature of the two interfaces. A hydrophilic top surface increased the rate of time-dependent change, while good adhesion of Parylene C to the metal decreased the extent of time-dependent change. With a hydrophobic top surface and good adhesion to the substrate, EIS characteristics of a Parylene C coated sheet remained unaffected for 18 days (the longest time employed in this study). The decrease in impedance in the low frequency region converges to the Bode plot for a freestanding Parylene C film. The early decline of EIS characteristics can be correlated to the (pre-corrosion) micro-delamination of the coating.     

Effects of substrate composition and roughness on mechanical properties and conformality of parylene C coatings

Nanoindentation was used to determine reduced elastic modulus E_r and hardness H of 16 μm thick Parylene C coatings vapor‐deposited on mill‐finished samples of aluminum, copper, nickel steel, and stainless steel. Profilometry was used to compare average surface roughnesses of the polymeric coatings to the roughnesses of the underlying metals, thereby providing a quantitative index for determining conformality. Roughness, elasticity, and hardness of coatings were found to be affected by both chemical composition and surface roughness of four different metallic substrates. Standard nanoindentation evaluations of E_r and H distributions for the various metals were found to be positively skewed, which precluded use of simple averages for purposes of comparison. However, analysis of the nanoindentation and profilometry data by use of alternative techniques indicated that coatings were consistently smoother and flatter than their underlying substrates, i.e., they were not truly conformal, and nanomechanical properties of Parylene C were affected by the chemical composition of the substrates independently of the effects of substrate roughness. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Outstanding performance of parylene polymers as electrets for energy harvesting and high-temperature applications

Parylene C is used in many applications due to its high properties but it remains a material with moderate performance as long as it is intended for use as an electret. Hence, the generally accepted idea, rightly so, in the scientific and industrial community not to necessarily select parylene (i.e., parylene C) for applications where the endurance of the electret is a strong criterion. Our study provided a new perspective on the performance of parylenes as electret. In this case, we will talk about fluorinated Parylenes of the VT-4 type and especially AF-4 variant. Their thermal stability is outstanding and a charge stability is almost total up to 100 °C. A 50% reduction in the charge is recorded at a temperature as high as of 220 °C (9 μm thick Parylene AF-4), making it one of the most efficient polymer electrets to date. Negatively and positively charged Parylene AF-4 electrets presented similar performance over long durations, which is out of ordinary for the commonly employed polymeric electrets. Finally, these fluorinated polymers are therefore particularly promising new candidates for applications in electret-based converters for energy harvesting. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48790.     

Parylene薄膜紫外光老化的研究进展

简要介绍了Parylene薄膜的优异性能以及主要应用范围。综述了国内外对Parylene薄膜在紫外光照射条件下老化行为的最新研究进展。讨论了紫外光老化的机理、主要现象、产物,以及老化对Parylene薄膜光学性能、透湿透气性能、力学性能、电磁学性能的影响。     

新型四合一除油除锈剂的研制

以磷酸、氧化锌、成膜剂、加速剂、配合剂等为主要原料,研究了一种室温多功能综合处理液,可在少量工序内完成除油、除锈、磷化、钝化4个过程,在钢铁表面形成一层致密均匀的灰色磷化膜。讨论了综合处理液的作用机理、主要成分的影响和作用,并测试了研制的处理液的技术性能指标。结果表明,所得涂膜附着力强,防锈性能好,处理液磷化方式可采用涂抹型,工艺简单,施工方便,适合于热轧薄板等无法入槽浸泡磷化的大型工件。生产的磷化膜具有优良的耐蚀性能、无污染。     

Convergent Pad Polishing of Amorphous Silica

A new method of optical polishing termed “Convergent Polishing” is demonstrated where a workpiece, regardless of its initial surface figure, will converge to the lap shape in a single iteration. This method of polishing is accomplished by identifying the phenomena that contribute to non-uniform spatial material removal, and mitigating the non-uniformity for each phenomenon (except for the workpiece-lap mismatch due to the workpiece surface shape). The surface mismatch at the interface between the workpiece and lap causes a spatial and time varying pressure differential which decreases with removal, thus allowing the workpiece to converge to the shape of the lap. In this study, fused (amorphous) silica workpieces are polished using ceria slurry on various polyurethane pads. Polishing parameters were systematically controlled to prevent various sources of non-uniform material removal which include: (i) moment force, (ii) viscoelastic lap relaxation, (iii) kinematics, (iv) pad wear, and (v) workpiece bending. The last two are described herein. With these mitigations, removal uniformity has been demonstrated to within 1.0 μm over the surface after 83 μm of material removal corresponding to a within workpiece non-uniformity (WIWNU) of <1.2%. Also, convergence has been demonstrated down to 0.18 ± 0.04 μm peak-to-valley flatness on 100 mm-sized workpieces.     

PVD-CrAlN and TiAlN coated Si3N4 ceramic cutting tools —1. Microstructure,turning performance and wear mechanism

In this work, CrAlN and TiAlN coatings were produced on silicon nitride cutting inserts via physical vapor deposition. The microstructure and hardness of the coatings, as well as the adhesive strength between the coating and the substrate were studied using a scanning electronic microscope, a micro hardness tester and a scratch tester, respectively. Continuous turning tests of the obtained CrAlN and TiAlN-coated silicon nitride cutting inserts were performed on gray cast iron to evaluate the cutting performances and the machining quality. The results show that the surface hardness of the Si₃N₄ cutting inserts could be improved by 87% and 50%, respectively, when applying the CrAlN and TiAlN coatings, thereby enhancing the abrasion resistance of the cutting inserts. At different tested cutting speeds, abrasive wear under compressional deformation and adhesive wear were identified as the main failure mechanisms for the two cutting inserts during continuous turning of gray cast iron. The machining quality of the gray cast iron workpieces machined using the uncoated, the CrAlN- or the TiAlN-coated inserts increased with the increment of the cutting speed.     

Effects of size, shape and floatage of Cu particles on the low infrared emissivity coatings

Low infrared emissivity coating was prepared by the copper (Cu) particles and ethylene–propylene–diene monomer (EPDM) binder. The effect of size, shape and floatage of Cu particles on infrared emissivity of the coatings was systematically investigated. The results indicated that the optimized Cu particles with the minimum coating emissivity are several micron-sized, flaky and high-leafing, exhibiting 0.78, 0.72 and 0.10 emissivity value, respectively. The formation of low infrared emissivity coatings depends strongly on the floatage of Cu particles, not the size or shape, and the results obtained by leafing aluminum (Al) and bismuth oxide (Bi₂O₃) pigment are in good agreement with this standpoint. A theoretical model was proposed to account for the mechanism, which indicated that the low porosity of the coatings with leafing pigments plays an important role in the formation of low emissivity coatings.