Adhesion of ABS resin to metals treated with triazine trithiol monosodium aqueous solution

An examination was made of the adhesion of ABS resin to treated metals such as phosphor bronze, brass plates, and electronickel platings during injection molding. No adhesion to any of these metals was noted to occur under ordinary injection molding conditions, and an aqueous solution of 1,3,5-triazine-2,4,6-trithiol monosodium (TTN) was thus used to induce adhesion. Following treatment with TTN aqueous solution under optimum conditions, ABS adhered tightly to all the above metals under ordinary injection molding conditions. TTN treatment led to the formation of surface films containing metal salts of 1,3,5-triazine-2,4,6-trithiol (TT). Conditions were made optimal with regard to time, temperature, and TTN concentration. Adherent films were generally formed when bronze and brass were treated for short periods, at low temperature, and at low TTN concentration, though not so in the case of nickel plating. There was adhesion to nickel plating in the case of prolonged treatment time, high temperature, and high TTN concentration. Adherent and non-adherent films did not differ in the chemical structures of the metal salts of TT but they differed in morphology. Good adhesion was noted in the case of TT-metal salts present at low density on the metal surface. Some films reacted readily with double-bond compounds under conditions similar to those generally used for the injection molding of ABS. It was concluded that the adhesion was due to the formation of interfacial bonds during injection molding.     

Direct adhesion of fluorinated rubbers to nickel-plated steel and nitrile rubber during curing using the tetrabutylammonium salt of 1,3,5-triazine-2,4,6-trithiol

A new curing agent, the tetrabutylammonium salt of 1,3,5-triazine-2,4,6-trithiol (TATT) for fluorinated rubber (FR) has been developed, from the point of view of making composite materials with metals and other rubbers. TATT was inferior in curing rate compared with a conventional polyol curing system, but imparted good properties to FR vulcanizates to the same extent as the polyol curing system. TATT-containing FR compounds easily adhered to electro- and electroless nickel-plated metals during vulcanization without an adhesive. The optimum concentration of TATT was around 1 phr for the peel strength of joints and the mechanical properties of vulcanizates. At a thickness exceeding 0.3 μm, nickel platings were very effective for making FR-Ni joints. In the direct adhesion between FR and nickel platings, interfacial bonds and a reinforcing layer at the interface between vulcanizates and nickel platings during vulcanization were important for obtaining FR-Ni joints of high peel strength. The newly prepared FR-Ni joints had very good heat, oil, and water resistance, compared with conventional FR-Fe joints prepared by using phenol-type adhesives. TATT was also a very effective agent for the direct adhesion between FR and NBR (nitrile butadiene rubber) during vulcanization because it acted as a common curing agent to various rubbers such as FR and NBR. Thus, TATT is a very effective curing agent for making composites of FR with various metals and elastomers.     

Crosslinking of PVC and NBR blends

The purpose of our work is to control the interfacial bonds between PVC and NBR using the ammonium salts of triazine thiols and dithiodimorpholine (DTDM) and thereby reveal the relation between the interfacial bonds and the final mechanical properties of products. In the experimental work a two-stage process was used. At first, an NBR/PVC blend was mixed with a mono-tetra-n-butylammonium salt of triazine trithiol at a temperature of 100°C on a two-roll mill to give the branching structure of triazine thiols into PVC. In the second stage branched NBR/PVC reacted with DTDM to afford the branched PVC containing trithiomorphonyl groups. In the presence of ZnO at 160°C trithiomorphonyl groups react with NBR to form a crosslinking structure between NBR and PVC. The mechanical properties of cured NBR/PVC blends were markedly improved by the treatment process and after addition of tetramethylthiuram monosulphide also. The mechanical properties were not improved by increasing the concentration of TT-TBA (tetrabutylammonium salt of 1,3,5-triazine-2,4,6-trithiol) over 4.2 phr.     

杂环硅烷自组装膜改性的聚丙烯表面镀铜研究

通过在电晕放电处理的聚丙烯(PP)表面自组装6-(3-三乙氧基硅基丙基氨)-1,3,5-三嗪-2,4-二硫醇单钠盐(TES)纳米膜后,进行了化学镀铜研究。考察了施镀温度、镀液pH值对镀速的影响,施镀时间对镀层厚度的影响,确定了最优工艺参数。在优化的工艺条件下制备镀层,用扫描电镜对镀层的形貌进行分析,并做了粘接性能测试。结果表明:最佳工艺为施镀温度为50℃,pH为13,施镀时间为50 min。采用此优化工艺条件制备的镀层,表观光亮,均匀致密,与基体结合力良好。     

Electroplating on crystalline polypropylene. II. Injection molding and adhesion

This paper describes the effect of injection molding conditions (melt temperature, mold temperature, and fill time) and etch conditions on metal adhesion in electroplated isotactic polypropylene (PP). It is found that injection molding PP homopolymer produces a lamellar surface morphology which can consistently develop after-plated peel strengths of 30 lb/in or better as measured by the Jacquet peel test. Surface etching of PP homopolymer prior to plating develops crack patterns characteristic of injection molding; a directional crack pattern is always evident in specimen surfaces crystallized under shear. The surface pattern is developed in the oxidative process by swelling of amorphous material, followed by oxidative dissolution and oxidative stress cracking. Additionally, the depth and number of the surface cracks is a function of the solvent swell and acid etch times. Crack depth increases in lamellar surfaces as the sample immersion times are increased; however, as crack depth increases, crack density decreases. Metal-to-polymer adhesion, as measured by the peel test, represents a balance between crack depth and diminished surface strength incurred in the oxidative cracking process. Although peel adhesion usually increases with crack depth, overetching may actually reduce adhesion even though the crack depth has been increased. Any advantage from deeper cracks may, therefore, be offset by a loss in the surface strength of the polymer. Comparison of the surface and cross-sectional crack patterns in TiO₂-filled PP indicates that the surface morphology is similar to that of unfilled polymer. Molding conditions that produce the desired morphology is similar to that of unfilled polymer. Molding conditions that produce the desired morphology are important for high peel adhesion values but appear to be less critical than in unfilled PP. A propylene–ethylene copolymer (90/10) developed 12–15 lb/in. peel adhesion—50% lower than for the filled and unfilled homopolymer when molded under similar conditions; peel adhesion in this composite system is, however, relatively insensitive to changes in molding conditions. Aging of 2–3 weeks after plating is required for maximum peel adhesion in all samples studied.     

铍青铜零件电镀金工艺

在铍青铜基体上采用镍作为中间层然后镀金是传统的镀覆方法.有些应用场合不允许采用镀镍而直接镀金,必须解决镀层与基体结合力的问题.分析铍青铜的特性和镀金层结合力不良的原因,提出了一种铍青铜直接电镀金的工艺流程和工艺参数,包括热处理疏松氧化层、微腐蚀、除钝化膜、镀金及封闭处理等工序,解决了铍青铜氧化层的去除及镀金层与基体结合...     

Rubber-to-metal bonding by silanes

This paper deals with the bonding of sulfur-vulcanized rubber compounds to metals. It had previously been reported that bis-(triethoxysilyl)ethane and vinyltriethoxysilane were found to work for bonding peroxide-cured rubber compounds to metals. These silanes were found not to work with sulfur-cured rubber compounds. In this case, a mixture of bis-(trimethoxysilylpropyl)amine and bis-(triethoxysilylpropyl) tetrasulfide was found to work and results are presented of experiments in which brass, steel, and electrogalvanized steel were bonded to a typical tire cord skim compound with and without a cobalt additive. This new silane treatment was found to be as effective as or better than brass adhesion to cobalt-containing rubber compounds. The superior corrosion protection offered by the silanes was also demonstrated using DC corrosion and polarization resistance measurements. The silane process reported in this paper behaves almost similarly with all metal substrates. In this paper, the structure of the silane film on a metal substrate is studied and a model is proposed for a possible mechanism of the adhesion of rubber compounds with silane-coated metals.     

Supercritical fluid dyeing of cotton modified with 2,4,6-trichloro-1,3,5-triazine

Supercritical carbon dioxide dyeing of cotton modified with the fibre reactive group 2,4,6-trichloro-1,3,5-triazine has been examined and the results are discussed. The modification of cotton was carried out in acetone, as well as by a new method using water as the solvent. For level dyeing results a degree of fixation of the fibre reactive group on cotton of 3% owf was required without changing the hydrophilicity of the fibre. The results show that dyeing of modified cotton is possible with dyes containing hydroxy or amino groups which react via a substitution reaction with the chlorine atoms of 4,6-dichloro-1,3,5-triazine-2-yl on the fibre surface. The K/S values at 383 nm of modified cotton dyed with CI Disperse Yellow 23 were found to be between 1.44 and 4.79 depending on the dyeing conditions used. The washing, rubbing and light fastness data that were obtained were between 3 and 5.     

镀锡青铜回火胎圈钢丝生产线

详细介绍了镀锡青铜回火胎圈钢丝生产线，包括镀前钢丝工艺和化镀锡青铜生产线的工艺流程、加工技术参数、设备组成及主要工序。采用此生产线生产的镀锡青铜回火胎圈钢丝性能优良，不仅具备在硫化过程中与轮胎橡胶整体达到良好的粘合的优势，并且具有在轮胎使用中、后期钢丝与橡胶粘合力稳定的特点。     

聚合物表面性能对强化冷凝传热的影响

对离子束动态混合注入(DIMI)技术制备的黄铜、紫铜、不锈钢和碳钢管基聚四氟乙烯(PTFE)表面的冷凝传热实验发现,用不同加工条件制备的表面具有不同的化学组成、不均匀的表面状态以及不同的物理化学性质,从而导致不同的冷凝成滴面积和传热性能,而且表面加工条件对滴状冷凝传热的寿命有至关重要的作用,不同基体材料应有不同的最佳制备工艺条件.不同工艺条件下制备黄铜基PTFE表面水蒸气竖直管外冷凝传热通量比相应的膜状冷凝提高0.3-4.6倍,冷凝传热系数提高1.6-28.6倍.实验结果也表明冷凝表面基体材料对冷凝传热性能有一定的影响.     

Mechanism and evaluation in electroinitiated copolymerization coatings of acrylonitrile and acrylic acid

Adherent films of copolymers on different metal surfaces were formed by an electrolytically initiated polymerization of acrylonitrile (AN) and acrylic acid (AA) in 0.05N H₂SO₄ aqueous solution. The electrolysis was carried out under a constant current. Hydrogen overvoltages for five different metals used as the cathode were measured in order to interpret the nature and quality of the coating. Solutions containing varying volume fractions of AN and containing different electrolytes gave rise to coatings of varying film thickness. Based on the analyses of copolymer compositions, it is believed that the polymer was formed at the cathode by a free-radical propagation mechanism. The film hardness and the adhesion between the polymer and the metal surface were measured with an Arco microknife. Furthermore, the scanning electron microscope (SEM) was used to examine the structure of the film surface and cross section. The corrosion rates of the coated and uncoated metals in substitute ocean water were also measured for purposes of evaluation of the coatings.     

Improvement of dimensional stability of nylon-6 block copolymer using phenolic resin by reaction injection molding

In order to decrease moisture uptake and hence provide rigidity and dimensional stability in a nylon-6 block copolymer (NBC), powdered phenolic resin was incorporated into the formulation as a filler and processed by reaction injection molding. A novolac resin was cured with hexamethylenetetramine to produce the phenolic resin, which was modified with diethylamine in order to remplaced the  OH groups by diethylamine groups. 5% by weight of modified and unmodified powdered phenolic resin was used as a filler in the nylon-6 block copolymers, and reinforced-nylon-6 block copolymer plaques were produced by reaction injection molding at 145°C. The materials were characterized by dynamic mechanical thermal analysis (DMTA), and their flexural modulus, impact test, and dimensional stability were evaluated. In unmodified phenolic-resin-reinforced nylon-6 block copolymer, water absorption was decreased by 90% compared with the NBC without filler. Two mechanisms of interaction between the NBC and the phenolic resin have been proposed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1811–1816, 1998     

Dimple-type failures in a polymer/roughened metal system

Roughening of metal surfaces frequently enhances the adhesion strength of polymers to metals by mechanical interlocking. When a failure occurs in a polymer/roughened metal system, the failure is prone to be cohesive within the polymer. In a previous work, an adhesion study on a polymer (epoxy molding compound, EMC)/roughened metal (brown-oxide-coated copper-based leadframe) system was carried out, and the correlation between the failure path and adhesion strength was investigated. In the present work, an attempt to explain why such failure paths occurred was made under the assumption that microvoids were formed in the EMC, as well as near the roots of the CuO needles during the compression-molding process. A simple adhesion model developed from the theory of fiber reinforcement of composite materials was introduced to explain the adhesion behavior and thereby explain the formation of failure paths. It is believed that the adhesion model developed in the present work can be used to explain the adhesion behavior of other similar polymer/roughened metal systems.     

氮化钛仿金镀层的耐磨性研究

采用多孤离子镀的方法,在1Cr13不锈钢及黄铜镀铬基体的表面上制备了氮化钛仿金装饰膜层。通过试验,得到了不同工艺参数情况下各种氮化钛膜层,采用盘销式摩擦磨损试验机测定了膜层的比磨损率。分析了膜层的耐磨性与各工艺参数间的关系,发现轰击电压的变化对膜层的耐磨性影响最大。     

Evaluation of catalytic efficiency of a triple-site phase transfer catalyst and the kinetics of dichlorocarbene addition to 5-vinyl-2-norbornene

A new triple-site phase transfer catalyst viz., 1,3,5-tris(ethylmethyleneammonium bromide)-2,4,6-trimethyl benzene (TEMABTB) was prepared by the quaternization of 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene using triethylamine and its catalytic efficiency was ascertained by following the kinetics of dichlorocarbene addition of 5-vinyl-2-norbornene. Comparative catalytic activity of various onium salts (single-, di- and tri-site) have been investigated in detail. Based on the kinetic results obtained, a plausible mechanism has been proposed.     

利用注射成型制造金属板／塑料宏观复合制件的方法

介绍了一种利用注射成型机将金属板成型、塑料注射成型和塑料与金属板的粘接融合为一体的制造金属板／塑料宏观复合制件的新工艺方法。论述了复合成型中塑料与金属板的粘接原理以及金属板表面处理的目的和塑料接枝极性单体的改性处理的作用，并以铝板为例进行了复合成型试验。     

The use of experimental design for the study of the corrosion of bronze pretreated with AMT in artificial rainwater

Copper and copper alloys (bronze and brass) are usually employed in the manufacturing of cultural objects. When these alloys are exposed to the atmosphere, damaging corrosion products may form on their surfaces. Corrosion inhibitors are used to minimize the corrosion processes. However, the conditions that obtain the best anticorrosive performance of these inhibitors require the control of several chemical and operational parameters, which are, in practice, often chosen empirically. An experimental design was employed to determine the best values with respect to the concentration of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT), the ethanol content and the immersion time of bronze in the AMT solution to achieve the most protective films on the bronze surface. Electrochemical impedance spectroscopy assays of bronze samples with and without previous immersion in the inhibitor solution and exposed to artificial rainwater were performed at the open circuit potential. The parameters and the influence of their interactions on the inhibitory effect of the film formed on the bronze surface were shown to be statistically significant. The conditions for achieving the most protective films were 0.060 M AMT, 90% v/v EtOH, and 90 min of immersion.     

Surface modification of synthetic vulcanized rubber

Surface modifications produced by treatments (mainly halogenation) of synthetic vulcanized styrene-butadiene rubber (SBR) leading to increased adhesion properties with polyurethane adhesives have been studied. T-peel tests, scanning electron microscopy (SEM), advancing contact angle measurements, infra-red (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and differential scanning calorimetry (DSC) were used to analyze the nature of surface modifications produced in the rubber. Although some surface heterogeneities were created, physical treatments (ultrasonic cleaning, solvent wiping, abrasion) did not noticeably increase the adhesion strength because certain abhesive substances (e.g. zinc stearate, paraffin wax) cannot be removed from the rubber surface by such treatments. Chemical treatment (chlorination) was carried out using ethyl acetate solutions of trichloroisocyanuric acid (TCI) (1,3,5-trichloro-1,3,5-triazine-2,4,6-trione). Chlorination of SBR with trichloroisocyanuric acid produced a significant improvement in T-peel strength, due to the contribution of mechanical (surface roughness, microcracks), thermodynamical (increase of polar contribution to the surface energy) and chemical (removal of abhesive substances, creation of polar groups) rubber surface modifications. The strong adhesion between the chlorinated SBR surface and the polyurethane adhesive was due to the presence of oxidized species of >C=O, -C-OH and -COR type. Chlorination of SBR is a fast reaction which needs only a small concentration of chlorination agent (< 1 wt% TCI/ethyl acetate) to produce high adhesion levels. An increased amount of TCI facilitated the chlorination reaction progressing from the exterior to the internal rubber bulk; however, although a thicker layer of chlorinated rubber created no further increase in adhesion strength was obtained.     

Conditions for ignition of copper and copper alloys in oxygen

Conditions for ignition of compact copper, brass, and bronze specimens in oxygen at pressures of 0.2–70.0 MPa in natural convection are studied by a thermographic method. For all the materials examined, the values of the ignition temperature are found not to depend on the pressure, and they are determined by the phase composition of the oxide films formed on the metals in the preignition period. Translated fromFizika Goreniya i Vzryva, Vol. 34, No. 2, pp. 47–50, March–April, 1998.     

化学镀的研究进展及在注塑机零部件中的应用

指出了近年来注塑机关键零件—螺杆使用过程存在的问题,详细论述了目前研究较多的几种化学复合镀的研究现状及其主要性能,指出化学复合镀中存在的不足并结合注塑机零部件目前存在的问题,论述了化学复合镀应用于注塑机行业的可行性。