Study of an environment-friendly surface pretreatment of ABS-polycarbonate surface for adhesion improvement

In this paper, an environmentally friendly etching system containing MnO₂–H₃PO₄–H₂SO₄ colloid was used to investigate surface etching for ABS- polycarbonate (PC/ABS) as a replacement for conventional chromic acid etching solutions. In order to obtain a good etching performance, a swelling system, containing tetramethylammonium hydroxide (TMAH), and 1-Methyl-2-pyrrolidinone (NMP), was used to investigate the surface swelling for PC/ABS resin. Then the effects of H₂SO₄ concentration, and etching time on the surface topographies and surface contact angle were investigated. After the optimal swelling and etching treatment, the surface contact angle of PC/ABS resin decreased from 95.7° to 28.3°, and the adhesion strength between electroless copper film and PC/ABS resin reached to 1.04 KN m⁻¹. The FT-IR spectra and XPS analyses indicated that hydroxyl and carboxyl groups formed on the PC/ABS surface as a result of the swelling and etching treatment, which improved the adhesion strength between PC/ABS substrate and elctroless copper film.     

Adhesion Improvement of ABS Resin to Electroless Copper by H2SO4–MnO2 Colloid with Ultrasound-Assisted Treatment

The adhesion strength between electroless copper and acrylonitrile-butadiene-styrene (ABS) resin can be improved significantly by an environmentally friendly etching system containing H₂SO₄–MnO₂ colloid as a replacement for conventional chromic acid etching solutions. In this paper, the effects of the H₂SO₄ concentration and ultrasound-assisted treatment (UAT) on the surface roughness and adhesion strength were investigated. When the H₂SO₄ concentration was 11.8～12.7 M, good etching was obtained. With UAT, many uniform cavities formed on the ABS surface with the average surface roughness (R _a) and maximum roughness (R _max) of ABS substrates decreasing from 386 and 397 nm to 278 and 285 nm, respectively, which were much lower than that etched by CrO₃–H₂SO₄ colloid (420 and 510 nm, respectively). The average adhesion strength increased from 1.29 to 1.39 kN/m, which was close to that obtained with chromic acid etching treatment (1.42 kN/m). The surface contact angle measurement indicated that the density of the polar groups on the ABS surface increased with increasing time of UAT. The results indicated that surface etching with UAT not only improved the uniformity of cavities, but also enhanced the oxidation rate of ABS resin, which in turn resulted in greater adhesion strength and a lower surface roughness.     

Electroless copper plating on acrylonitrile butadiene styrene material surfaces without chromic acid etching and a palladium catalyst

Hydrolysis modification of nitrile groups on acrylonitrile butadiene styrene (ABS) plate surfaces into carboxylic acid groups was investigated to find a new recipe for electroless copper plating of ABS plate surfaces without etching reactions using chromic acid and also without a palladium catalyst. Hydrolysis modification of nitrile groups was successfully conducted in an aqueous sodium hydroxide (NaOH) solution (70 wt %) at 80°C for more than 72 h, and nitrile groups were modified into carboxylic acid groups. The hydrolysis modification was accelerated by the addition of dioxane as a supplement to the aqueous NaOH solution. The modification, when an aqueous mixture solution of NaOH (35 wt %) and dioxane (10 wt %) was used as a reagent, was accomplished at 65°C in 30 min. The hydrolyzed ABS plate surfaces were successfully metalized by electroless copper plating. A silver catalyst, instead of a palladium catalyst, was usable in the electroless copper‐plating process. Adhesion between the deposited copper metal and ABS plate surface was perfect for the Scotch tape test. Consequently, we propose a new recipe for an electroless copper‐plating process without an etching process using chromic acid and without a palladium catalyst. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Surface modification of ABS by photocatalytic treatment for electroless copper plating

Surface roughness of acrylonitrile–butadiene–styrene (ABS) resin prior to metallization is treated generally with sulphuric/chromic acid system. However, the presence of chrominum (VI) ion imposes serious environmental problems. In this work, TiO₂ photocatalytic treatment was used to enhance the adhesion strength between the ABS surface and the electroless copper film. Effects of the TiO₂ content, irradiation time and UV power upon the surface topography, surface characterization and the adhesion strength were investigated. The results indicated that the surface hydrophilicity of ABS resin and the adhesion strength between the electroless copper film and ABS surface increased with an increase in the UV power and a prolongation in irradiation time, and did not increase linearly with an increase of TiO₂ content. Though the surface topography of ABS changed little, the adhesion strength reached 1.25?kN/m, which was higher than that in the optimal H₂SO₄–MnO₂ colloid. The surface chemistry results indicated that –COOH and –OH groups formed with the photocatalytic treatment and the absorption strengths increased with the UV power. XPS analysis results further demonstrated that the contents of C=O and –COOH reached 6.4 and 4.9% with the photocatalytic treatment, which was much higher than that of the H₂SO₄–MnO₂ colloid (3.9 and 3.1%). The high contents of C=O and –COOH groups enhanced the surface hydrophilicity of the ABS resin and improved the adhesion strength between the electroless copper film and ABS resin. The results indicated that the photocatalytic treatment was an environment-friendly and effective method to replace the commercial wet chemical process for ABS surface modification.     

Adhesion improvement of electroless copper to PC substrate by a low environmental pollution MnO2–H3PO4–H2SO4–H2O system

A low environmental pollution etching system, MnO₂–H₂SO₄–H₃PO₄–H₂O colloid, was used to investigate surface etching performance of polycarbonate (PC) as a replacement for the chromic acid etching solution. The effects of H₂SO₄ concentrations, H₃PO₄ concentrations and etching times upon the surface topography, surface chemistry and surface roughness were studied. With the appropriate etching treatment, the surface average roughness (R_a) of PC substrates increased from 3 to 177 nm, and the adhesion strength between the electroless copper and PC substrate also reached 1.10 KN m⁻¹. After the etching treatment, the PC surface became hydrophilic and the surface contact angle decreased from 95.2° to 24.8°. The intensity of C–O groups increased and the new functional groups (–COOH) formed on the PC surface with the etching treatment, which improved the adhesion strength between PC substrate and elctroless copper film.     

Evaluation of the etching and chrome plating on the ABS,PVC, and PVC/ABS blends surface

As replacement for acrylonitrile‐butadiene‐styrene (ABS), which is commonly used in the manufacture of chrome parts, polyvinyl chloride (PVC) and PVC/ABS blend parts were produced by injection process, etched in sulfochromic solution in different concentrations, immersion time, and temperature, and they were subsequently chrome‐plated by conventional method. After etching, the sample surfaces were analyzed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), roughness, and contact angle, and compared with the ABS surface. The metal deposition was assessed by visual inspection and adhesion test. The roughness influenced the adhesion of the metal layer directly. The chemical etching increased the surface wettability. To achieve a good metal layer adhesion, higher temperatures, immersion time, and etching solution concentration were necessary. A concentration of 350 g/L chromic acid and 400 g/L sulfuric acid, a 70 °C temperature and a 15 min immersion time resulted in good adhesion in PVC and PVC/ABS blends. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44571.     

高锰酸钾溶液粗化环氧树脂板的研究

在不同的微蚀温度、时间条件下,研究了高锰酸钾微蚀溶液对环氧树脂层压板和3240型环氧树脂板(基板)微蚀作用的影响。通过基板表面形貌的观察和对化学镀铜层与基板间粘结强度的测定,研究和比较了高锰酸钾体系和传统的铬酐-浓硫酸体系对两种基板的微蚀效果。结果表明,经过高锰酸钾溶液处理后,环氧树脂层压板和3240型环氧板粘结强度分别可达到5.88 N/cm和2.35N/cm,远远高于传统的铬酐-浓硫酸处理后镀铜层与基板的粘结强度;同时,使用高锰酸钾溶液可以减小环境污染,且操作简单易行,它作为新型的微蚀体系有望取代传统的铬酐-浓硫酸微蚀体系。     

Preparation of nickel coating on ZTA particles by electroless plating

With the aim to effectively improve the interface between ZrO₂ toughened Al₂O₃ (ZTA) particles and metal matrix, nickel was deposited on the surface of ZTA particles by electroless plating method. Formation mechanism of nickel coating and effects of the solution pH, loading capacity of ZTA particles and temperature on the nickel deposition were investigated. Microstructures, thickness and element distributions of nickel coating were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results showed that the nickel was successfully deposited on the surface of ZTA particles by electroless plating without noticeable defects. The process of electroless nickel plating could be explained by combination of atomic hydrogen and electrochemistry theories. The interfacial nucleation of nickel is easier to form than spontaneous nucleation in the solution. Deposited Nickel has priority on the surface of ZTA particles comparing to that in solution. The optimal conditions to coat nickel on the surface of ZTA particles are: solution pH 4.7–4.8, loading capacity 15–20?g/L, and electroless plating temperature 85?°C. The ZTA particle reinforced iron matrix composites prepared by powder metallurgy could have better interfacial bonding between ZTA particle and iron matrix because of the nickel coating on the surface of ZTA particle. Nickel diffuses into the iron matrix during the sintering preparation of composite materials. The interface between ZTA particle and iron matrix presents the evidence of non-chemical bonding.     

A study of the environmentally friendly polycarbonate surface etching system containing H2SO4–MnO2 colloid

In this paper, an environmentally friendly etching system containing H₂SO₄–MnO₂ colloid was used to investigate surface etching for polycarbonate (PC). The effects of swelling condition, H₂SO₄ concentrations and etching times on surface topography and surface roughness were studied. With the etching treatment, the surface average roughness (R _a) of PC substrates increased from 3 to 76?nm and the adhesion strength between the electroless copper and PC substrate reached 1.08 KN/m. Surface chemistry of PC substrates was investigated by the contact angle measurement and X-ray photoelectron spectroscopy spectra (XPS). After the etching treatment, PC surface became hydrophilic and the contact angle decreased from 95.2 to 39.6^o. XPS analyses indicate that hydroxyl and carboxyl groups are formed on the PC surface as a result of the etching treatment, which improve the adhesion strength between PC substrate and electroless copper film.     

Electroless plating of moisture‐curable polyurethane undercoating films

The compatibility of using moisture‐curable polyurethane (MCPU) system as a thin undercoating layer with electroless plating process was evaluated. The characteristics of the MCPU before and after chemical etching treatment were analyzed using atomic force microscope (AFM), scanning electrode microscope (SEM), contact‐angle measurements, and (Fourier‐Transform Infrared) FTIR spectroscopy. We found that surface morphology and roughness of the MCPU is affected by curing period and etching times. A proper combination of curing period and etching times are critical for obtaining a fully metallized surface. All MCPU samples that were etched for 15 min show poor plating performance due to surface damage caused by mild etching treatment. A standard pull‐off testing method (ASTM 4541) was used to evaluate the adhesion strength of nickel–MCPU. Only samples that were postcured for 4 days show influence of surface roughness on adhesion strength. On average, samples that were postcured for 7 days before electroless plating showed better adhesion of nickel–MCPU compared with samples that were postcured for 2 or 4 days. The results show that MCPU system can be used as a thin undercoating layer for electroless plating. It also offers smooth metal–polymer interface and therefore has the potential to be exploited for use in many electroless plating applications including in the decorative such as ornaments and display items and also in electronic industries. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1554–1565, 2007     

Effect of surface preparation on electroless Ni‐P plating on carbon fiber‐Reinforced Cyanate Ester Resin Laminate

The effect of surface preparation on electroless Ni‐P plating on carbon fiber reinforced cyanate ester resin laminate has been investigated. Three different surface chemical etching ways were performed, namely: (i) hexanediamine etching, (ii) hexanediamine followed by aniline etching, and (iii) aniline etching. The results indicated that Ni‐P coating on hexanediamine etching or hexanediamine followed by aniline etching pretreated carbon fiber reinforced cyanate ester resin laminates usually tended to be cracked, veined, and low adhesion, while aniline etched laminates showed a homogenous roughing surface which is suitable for subsequently uniform, cellular, and good adhesion Ni‐P plating. POLYM. COMPOS., 37:1161–1166, 2016. © 2014 Society of Plastics Engineers     

Effects of mold cavity temperature on surface quality and mechanical properties of nanoparticle‐filled polymer in rapid heat cycle molding

Acrylonitrile‐butadiene‐styrene (ABS)/poly methyl methacrylate (PMMA) and ABS/PMMA/nano‐CaCO₃ composites were prepared in a corotating twin screw extruder. Single‐gate and double‐gate samples were molded based on a rapid heat cycle molding (RHCM) system. Effects of mold cavity temperature on surface quality and mechanical properties of single‐gate and double‐gate samples in RHCM process were conducted. The results showed that surface quality of plastic parts can be improved significantly by increasing mold cavity temperature. Nano‐CaCO₃ particles on the surface of plastic parts can be eliminated by using high mold cavity temperature. The roughness and gloss of two kinds of plastic parts (ABS/PMMA and ABS/PMMA/nano‐CaCO₃) stabilized at the same level when the mold cavity temperature is above glass transition temperature of resin material. Weld line can be eliminated in RHCM process during high mold cavity temperature. The tensile strength of both ABS/PMMA and ABS/PMMA/nano‐CaCO₃ exhibited decreasing trend with the increase of mold cavity temperature. Reduction of internal stress gave rise to the increase of Izod impact strength of ABS/PMMA for both sing‐gate and double‐gate samples. However, influence regularity of mold cavity temperature on Izod impact strength of ABS/PMMA/nano‐CaCO₃ is depended on the number of gates. For all the samples in this study, too high of mold cavity temperature (higher than 125°C) deprave Izod impact strength of plastic parts. Both ABS/PMMA and ABS/PMMA/nano‐CaCO₃ are not susceptible to weld line. When the mold surface temperature is approximately equal to glass transition temperature of resin material, all the samples are found to give the best combination of properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41420.     

Chemical modification of LDPE film

Low‐density polyethylene (LDPE) film was chemically modified by chromic acid treatment to generate polar groups on the surface. The film samples were etched by chromic acid with variation of temperature at a constant time (30 min) and variation of time at a constant temperature (room temperature = 26°C). The variation of weight and thickness of the film samples before and after etching was measured. The surface morphology of the etched films was studied by Scanning Electron Microscopy (SEM). IR and XPS analysis revealed the introduction of polar groups like  COOH, 〉CO,  SO₃H on the etched LDPE film surface, which exhibited improved printability. Etching also enhanced adhesion with epoxy resin. The mechanical properties of the laminates of the two specimens of the same film sample with epoxy resin were also measured. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1041–1048, 1999     

预处理的优化与计算机结果分析

化学镀方法较电镀方法更适合于在微米级颗粒表面镀覆突起的刺状金属镀层。通过调整镀液组成和施镀工艺参数,得出亲水性和化学镀工艺参数是影响人造金刚石表面化学镀镍磷合金形貌的主要因素。结果表明为了确保人造金刚石表面呈现良好的亲水性,实现中应该采用镀液能够很好的润湿与接触;在电镀化学过程中采用铬酸洗液可以实现金刚石表面的活性提高,这一结果对于微纳量级的金刚石顺利电镀非常关键。     

A New Surface Etching Method Using MnO2/H2SO4 Colloid for Adhesion Improvement of Epoxy Polymer

Abstract

A new surface etching method using MnO₂/H₂SO₄ as the etchant to improve the adhesion between an epoxy polymer surface and a metallic layer, was studied. The effects of bath temperature, etching time and H₂SO₄ concentration on the surface topography and chemical properties were investigated. After the etching treatment of the MnO₂–H₂SO₄ colloid, not only did the surface roughness increase remarkably, but also the surface of epoxy became hydrophilic and the contact angle of the epoxy surface was also decreased from 93.5° to about 8.0°. The X-ray photoelectron spectroscopy analysis indicated that as a result of the etching treatment, hydroxyl, carbonyl and carboxylic acid groups formed on the epoxy surface. The adhesion strength was markedly enhanced with the appropriate etching treatment, which was attributed to the improvement of the surface roughness and the increased hydrophilicity.     

Micro-nano hybrid structures with manipulated wettability using a two-step silicon etching on a large area

Nanoscale surface manipulation technique to control the surface roughness and the wettability is a challenging field for performance enhancement in boiling heat transfer. In this study, micro-nano hybrid structures (MNHS) with hierarchical geometries that lead to maximizing of surface area, roughness, and wettability are developed for the boiling applications. MNHS structures consist of micropillars or microcavities along with nanowires having the length to diameter ratio of about 100:1. MNHS is fabricated by a two-step silicon etching process, which are dry etching for micropattern and electroless silicon wet etching for nanowire synthesis. The fabrication process is readily capable of producing MNHS covering a wafer-scale area. By controlling the removal of polymeric passivation layers deposited during silicon dry etching (Bosch process), we can control the geometries for the hierarchical structure with or without the thin hydrophobic barriers that affect surface wettability. MNHS without sidewalls exhibit superhydrophilic behavior with a contact angle under 10°, whereas those with sidewalls preserved by the passivation layer display more hydrophobic characteristics with a contact angle near 60°.     

Surface modification of polyimide by combining swelling and TiO2 photocatalytic treatments for adhesion improvement of electroless Cu

In order to enhance the adhesion strength between the PI film and the electroless copper film, a combination of swelling and TiO₂ photocatalytic treatments was used to modify polyimide (PI) film. The effects of the swelling solution composition and TiO₂ photocatalytic condition on the surface performance were investigated. After the optimal swelling and photocatalytic treatment, the surface contact angle of the PI film decreased from 85 to 28.7°, and the surface average roughness of the PI film only increased from 1.3 to 13.6?nm, indicating no obvious change for the surface topography of PI film after the photocatalytic treatment. However, the adhesion strength between electroless copper film and the PI film reached to 0.6?KN·m^?1. The FT-IR spectra and XPS analyses indicated that –COOH group was formed on the PI surface after the treatment, and the surface hydrophilicity was improved, which improved the adhesion strength between the PI film and the electroless copper film.     

Utilizing the autocatalysis of Co to prepare low-cost WC-Co powder for high-performance atmospheric plasma spraying

A novel method of incorporating fluidized bed chemical vapor deposition (FBCVD) with electroless plating was developed to effectively prepare the core-shell structured WC-Co composite powders. The Co nanoparticles decorated on the surface of WC particles by FBCVD acted as active catalysts for the subsequent electroless plating process. The particle size and quantity of the decorated Co particles determined the electroless plating rate but the particle size played more important role. For the conditions tested, the maximum electroless plating rate of 2.34 mg/g/min was obtained by using an optimal FBCVD pretreatment at 750°C for 3 minutes. WC-12Co composite powders with a commercial composition widely used for atmospheric plasma spraying (APS) were efficiently prepared. The composite powders exhibited excellent suitability for APS by forming a homogenous Co-W-C ternary liquid stream. The APS coating is not only well-bonded with the substrate but also consisted of hard nonequilibrium Co₃W₃C and W₂C phases with a uniform distribution. Both remarkably improved the hardness and tribological properties of the APS coating.     

金刚石化学镀镍预处理工艺的改进

为了改进金刚石切割片中的树脂结合剂与磨粒之间相互的粘结程度,以希望达到覆着刺状金属层效果,文中对金刚石化学镀的预处理工艺进行了优化改进。采用了将金刚石粉末加入铬酸洗液中进行浸泡11 h的亲水处理,选择了离子钯活化液实现活化处理。实验结果表明:未经亲水化处理的镍-磷镀层,部分晶面出现漏层现象,而亲水处理过的镀层无此现象;改进工艺能够实现凹凸不平的较厚的镀层的形成;酸性镀液的沉积速率相对较快,但采用该镀液获得的镀层的形貌大都平整光滑,很少出现刺状镀层,碱性镀液沉积速率虽然较低,但施镀温度低,镀液络合稳定常数较高,镀液更稳定,且在碱性镀液中更容易实现人造金刚石表面的刺状镀层的获得。     

The effect of TiO2 morphology on the surface modification of poly (ethylene terephthalate) for electroless plating

In this study, a surface modification of the poly (ethylene terephthalate) (PET) film using TiO₂ photocatalytic treatment was investigated. In order to enhance the adhesion strength between the PET film and the electroless copper film, the effects of TiO₂ crystal forms, TiO₂ particle sizes, and TiO₂ content, as well as treatment condition, upon the surface contact angle, surface characterization, and adhesion strength were investigated. Anatase TiO₂ with a particle size of 5 nm had a high catalytic activity and dispersibility in aqueous solution. After the optimal photocatalytic treatment, the surface contact angle of the PET film decreased from 84.4° to 19.8°, and the surface roughness of the PET film increased from 36 to 117 nm. The adhesion strength between the PET film and the electroless copper film reached 0.89?KN?m^?1. X-ray photoelectron spectroscopy analyses indicated the carbonyl group was formed on the PET surface after photocatalytic treatment, and the surface hydrophilicity was improved. Consequently, TiO₂ photocatalytic treatment is an environmentally friendly and effective method for the surface modification of the PET film.