Aqueous pretreatments of polyetherimide to facilitate the bonding of electrolessly deposited copper

A chemical method for pretreating polyetherimide substrates to promote adhesion to copper is described. The process consists of cleaning the polymer surface followed by surface normalization, debris solubilization, and adhesion promotion via chemical modification of the polymer surface. Classes of candidates for each of the major steps are described and the optimal agents assembled into a recommended procedure. Peel strengths between 150-210 g mm^-1 for copper to polyetherimide were achieved utilizing the suggested scheme. Scanning electron microscopic and X-ray photoelectron spectroscopic analyses were employed to investigate changes in the polymer surface and chemistry during processing. Metallized specimens were examined after 90° peel testing and the failure locus found to be within the polymer layer.     

Development and thermal durability of an interfacial bond between electrolessly deposited metals and a fluorinated polyimide

The oxygen content of a fluorinated polyimide surface can be increased by exposure to an oxidant such as an alkaline permanganate solution. Deposition of an electroless metal layer on this oxidized surface results in the formation of an interfacial bond which is predominantly chemical in nature. The level of adhesion achieved depends both on the surface oxidation conditions and post-plating heating. Adhesion maxima are obtained by heating to 200°C for an electroless Cu deposit and to 300°C, the cure temperature for the polyimide film, for deposited electroless Ni. The fluorinated polyimide used in this study was derived from the reaction of 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane with pyromellitic dianhydride and was obtained from Ethyl Corporation as Eymyd® L30N resin.     

清洗预处理对手表外观件表面镀类金刚石薄膜性能的影响

为解决手表外观件镀层的附着力和硬度不高而产生的膜层脱落和磨损露底等问题,采用阳极层流型气体离子源结合非平衡磁控溅射技术制备了类金刚石膜层,研究了镀前清洗工艺对膜层附着力和耐磨性能的影响.结果表明,所制备的类金刚石膜均匀亮黑,显微硬度为2 232 HV,摩擦系数为0.15.在同一镀膜工艺条件下,手表外观件经彻底清洗后,其...     

The effect of pretreatment of the metal surface on the bonding strength of a composite of strip steel,primer and PVC

Some parameters which influence the adhesion interactions in the interface layers of a multilayer system comprising strip steel, primer and polyvinyl chloride have been investigated. A distinct relationship was found between the pretreatment of the metal surface and the bonding strength, both of which were remarkably affected by the functional groups of the modified acrylate primer.     

Surface modification of tetrafluoroethylene–hexafluoropropylene (FEP) copolymer by remote H2, N2, O2, and Ar plasmas

Tetrafluoroethylene–hexafluoropropylene (FEP) copolymer sheets were modified by remote H₂, N₂, O₂, and Ar plasmas, and the effects of the modification on adhesion between FEP sheets and copper metal were investigated. The four plasmas were able to modify the FEP surfaces' hydrophilicity. Defluorination and oxidation reactions on the FEP surfaces occurred with exposure to the plasma. The hydrophilic modification by H₂ plasma was best, followed by modification by O₂, Ar, and N₂ plasmas. The surface modification of FEP by all four remote plasmas was effective in improving adhesion with copper metal. The peel strength order of the FEP/Cu adhesive joints was H₂ plasma > Ar plasma > N₂ plasma > O₂ plasma. Mild surface modification is important for the adhesion improvement of FEP with Cu metal. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1258–1267, 2002     

Analysis of the Molecular Structure at the PPS/Copper Interphase and its Role in Adhesion

X-ray photoelectron spectroscopy (XPS) was used to examine the interfacial chemistry in polyphenylene sulfide (PPS)/copper bonded laminates. Several surface pretreatments were studied including a simple methanol wash, two acid etches, thermal oxidation and chemical oxidation. Peel test analysis showed poor adhesion to the methanol-washed and acid-etched foils, giving a peel strength of only 3-5 g/mm. XPS analysis of the failure surfaces revealed a large amount of inorganic sulfide at the interface with reduction of the copper oxide. Chemical oxidation using an alkaline potassium persulfate solution gave a matt-black surface consisting of primarily cupric oxide. These samples showed improved adhesion and XPS analysis of the failure surfaces revealed fracture through a mixed PPS/cuprous oxide layer. A simple thermal oxidation yielded a cuprous oxide surface layer and laminates bonded to these surfaces showed a more than ten-fold increase in peel strength. XPS analysis of the failure surfaces showed much lower amounts of interfacial copper sulfide and it was postulated that excess sulfide at the interface was responsible for the poor adhesion observed for other pretreatments.     

Removal of toxic metals from aqueous mixtures. Part 1: Biosorption

The biosorption of toxic metals from an aqueous mixture containing zinc, copper and nickel, in the presence of calcium and sodium ions (usual co‐existing cations in related systems) has been investigated. Industrial biomass samples of different origin have been examined batchwise as effective sorbents, including bacteria (Streptomyces rimosus), fungi (Penicillium chrysogenum) and yeasts (Saccharomyces carlsbergensis and Saccharomyces cerevisiae). The effect of solution pH was evaluated in the range of 3–11.5. Selectivity was observed, particularly for the removal of copper. The observed removal of metals by the application of biosorption was also compared in laboratory experiments with other more conventional separation techniques (filtration, centrifugation and flotation). © 1999 Society of Chemical Industry     

KDF过滤介质在反渗透预处理中的应用

介绍了一种反渗透预处理的新方法，阐述了应用KDF过波介质控制结垢形成，减少悬浮固体，减少氧化剂，控制细菌和藻类，减少重金属和减少硫化氢的机理，并给出了应用实例。     

Nickel interlayer on the microstructure and property of TC6 to copper alloy diffusion bonding

In the present study, diffusion bonding of two dissimilar materials TC6 and copper alloy was investigated in vacuum chamber by directly bonding and using Ni foil as interlayer. Interface quality of the joints was evaluated by mechanical property and microstructure. The maximum shear strength of directly bonding was found to be 64 MPa for the speciemen bonded at 850 °C, 5 MPa for 30 min; and the maximum shear strength with Ni foil interlayer was 113 MPa under the same bonding parameters. The bonding interfaces and fracture surfaces were analyzed by energy disperse spectrometer, scanning electron microscopy and X-ray diffraction. The results show that the diffusion region of directly bonding specimen generated several IMCs (Ti₂Cu and Ti₅CuSn₃, etc.). Fracture morphology showed that brittle fracture present at the Ti₅CuSn₃ IMCs, which was the weak point of the joint. While the diffusion zone of the specimen with Ni foil interlayer consists of various phase including Ti₂Ni, TiNi, TiNi₃ at TC6 side, and Cu-Ni solid solution at ZQSn11-4-3 side, and fracture surface of joint present a mixture of brittle and ductile characteristics, and fracture initiated at the TiNi₃/Ni interface.     

Ceramic membrane pretreatment of monosodium glutamate isoelectric supernatant to facilitate (NH4)2SO4 recovery by electrodialysis

BACKGROUND: The large output of monosodium glutamate in China has produced huge amounts of isoelectric supernatant containing 40–60 g L⁻¹ (NH₄)₂SO₄. With the increasing national emphasis on environmental protection and recycling, it is necessary to find a cost‐effective and environment‐friendly alternative to recover the (NH₄)₂SO₄. This paper reports on investigations of the electrodialysis process for (NH₄)₂SO₄ recovery from isoelectric supernatant pretreated by ceramic membrane. RESULTS: For ceramic membrane pretreatment, the optimal pore size chosen was 0.2 µm. After a 250 min run, permeate flux was still maintained at 90 L m⁻² h⁻¹ (v = 2.8 m s⁻¹, ΔTMP = 0.12 MPa, concentration factor = 7). Meanwhile, the total solids and proteins content in condensed supernatant were high, up to 78 g L⁻¹ and 24 g L⁻¹, respectively, which greatly favors future cell protein harvest. With the chosen current density of 17 mA cm⁻², the energy consumption and time for six consecutive batches for electrodialysis were 2.6–2.7 kW h kg⁻¹ sulfate and ∼100 min, based on ∼80% ammonium sulfate recovery from pretreated isoelectric supernatant. CONCLUSION: Ceramic membrane pretreatment was shown to be a promising pretreatment strategy, applicable to the electrodialysis process to recover ammonium sulfate from isoelectric supernatant produced during monosodium glutamate production. Copyright © 2008 Society of Chemical Industry     

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.     

Effect of bio-alkyd resin oil content and viscosity on the adhesion of EPDM to polyester fabric

Three types of bio-alkyd resins varies in their oil content and viscosity were added to EPDM rubber mix loaded by three bonding system consisting of Hexamethylenetetramine, Resorcinol and Hydrated silica (HRH). The mixes were charged by certain amount of thermal carbon black. Rubber dough was spread on polyester sheet fabric. The peel strength was used to measure the adhesion strength. The rubber-proofed fabric subjected to UV irradiation at different period of times. The dielectric constant, volume resistivity, thermal stability, water and air permeability of the various rubber coated fabric were examined. The addition of the bio-alkyd resin improved the various mechanical and physical properties of the rubber coated fabric materials. The suggested mechanism of bio-alkyd resin between EPDM and polyester fabric was also studied.     

Improvement in the adhesion between copper metal and polyimide substrate by plasma polymer deposition of cyano compounds onto polyimide

The surface modification of Kapton film by means of plasma polymer deposition is discussed from the viewpoint of improving the adhesion between copper metal and Kapton film substrate. Plasma polymers of AN (acrylonitrile) and FN (fumaronitrile) were used for the surface modification, and the adhesion between the copper metal and the plasma polymer-coated Kapton film was evaluated by the T-peel strength measurement. The surfaces of peeled layers were analyzed by X-ray photoelectron spectroscopy (XPS) and the failure mode is discussed. The plasma polymer deposition of AN and FN shows an effective improvement in the adhesion between the copper metal and Kapton film; in particular, the AN plasma polymer deposition increased the peel strength 4.3 times. Failure occurred mainly in the Kapton film, and the adhesion between the AN plasma polymer and the Kapton film and that between the copper metal and the AN plasma polymer were found to be quite strong.     

Effect of bonding systems on the adhesion of butyl rubber to polyester fabric

An adhesion promoter system composed of hexamethylene tetramine, resorcinol, and hydrated silica was compounded with butyl rubber mix. This mix was spread over untreated polyester fabric. The resorcinol was also replaced by o-aminophenol, m-aminophenol, or m-phenylene diamine. The rubber-fabric materials were subjected to aging or exposed to ionizing radiation. The peel strength, permeability, dielectric constant, and electrical resistivity were examined.     

Adhesion of polyvinyl alcohol cord,and fabric to special purpose rubbers in the presence of HRH dry-bonding agents

The adhesion of polyvinyl alcohol (PVOH) cord and fabric to different special purpose rubbers has been studied with a view to making use of the textile in various applications such as in gaskets, diaphragms, and other industrial molded goods. Adhesion was measured with both raw and chemically treated cords and fabrics, and in the presence of hydrated silica-resorcinol-hexamethylenetetramine (HRH) dry-bonding agents. The pull adhesion strength of the PVOH cable cord (untreated) to EPDM rubber and polyurethane rubber improved significantly on incorporating HRH dry-bonding agents. However, for chemically treated cords the bond strength improved for EPDM rubber but decreased marginally for polyurethane rubber. The peel adhesion strength of the PVOH fabric (both raw and chemically treated) improved slightly with the introduction of dry-bonding agents for all the rubbers studied except nitrile rubber. The physicomechanical properties and aging characteristics of the rubber vulcanizates in the presence of the dry-bonding agents are reported.     

Tantalum and chromium adhesion to polyimide. Part 2. Peel and locus of failure analyses

Ta and Cr adhesion to 3,3'-4,4'-biphenyl tetracarboxylic acid dianhydride-p-phenylenediamine derived (BPDA-PDA) polyimide (PI) surfaces has been studied before treatment, and after CF₄ reactive ion etching (RIE), and Ar sputtering. The initial peel adhesion results for both metals on the BPDA-PDA surfaces are comparable and show increased peel adhesion as a function of the surface treatment in the following order: virgin (no treatment) < Ar sputter < CF₄ RIE ~ CF₄ RIE followed by Ar sputter. The surface roughness effect on metal/PI adhesion has also been investigated. The data suggest that the surface roughness does not primarily affect peel adhesion. In this case, it is the removal of the weak boundary layer and the cracking of the residual PI on the metal peel interface surface during the peeling process which cause the increase in the peel strength. It is also proposed that the changes observed in the peel strength as a function of the surface treatment are due to differences in the fracture toughness of the modified PI layers rather than differences in the surface roughness.     

Use of the Blister Test to Study the Adhesion of Brittle Materials. Part II. Application

Using a modified form of the blister test, where the adhesive layer was between the substrate and a massive base, instead of as a continuous sheet on top of the substrate, we determined the interfacial fracture energy F for a series of interfaces where a brittle material (ice) was adhering to various substrates. Fracture energies obtained were compared with work of adhesion values measured for water on the same substrates. Fracture energy, which contains within it both a reversible contribution due to intermolecular interactions across the interface (work of adhesion) and an irreversible contribution due to collective dissipative processes, was found to rise rapidly with modest increases in work of adhesion. The observed relation suggests that the irreversible contribution to fracture energy is influenced strongly by the intermolecular interactions at the interface.     

Use of the Blister Test to Study the Adhesion of Brittle Materials. Part II. Application

Using a modified form of the blister test, where the adhesive layer was between the substrate and a massive base, instead of as a continuous sheet on top of the substrate, we determined the interfacial fracture energy F for a series of interfaces where a brittle material (ice) was adhering to various substrates. Fracture energies obtained were compared with work of adhesion values measured for water on the same substrates. Fracture energy, which contains within it both a reversible contribution due to intermolecular interactions across the interface (work of adhesion) and an irreversible contribution due to collective dissipative processes, was found to rise rapidly with modest increases in work of adhesion. The observed relation suggests that the irreversible contribution to fracture energy is influenced strongly by the intermolecular interactions at the interface.     

Evaluation of a new test method to determine the failure mode and macro-shear bond strength of dental materials to metals

Objective: To compare the macro mean shear bond strength (SBS) and failure mode of three cements to two types of metal using mould-enclosed and non-enclosed cement specimens. Methods: Titanium and base metal cobalt-based substrates were finished with 50 μm aluminium oxide. Two resin-modified glass-ionomers (Riva Luting Plus, Fuji Plus) and one resin cement (RelyX Unicem) were prepared as per manufacturers’ instructions. Metal mould-enclosed and non-enclosed cement specimens with a bonding area diameter of 3.5?mm were prepared and stressed to failure using a 2 mm blunt edge shear knife at a cross-head speed of 1?mm/min to determine mean SBS. The shear knife was placed against the surface of the substrate. Failure analysis of the failed interface was performed with a stereo microscope at 40× magnification. Results: Two-way Analysis of Variance demonstrated a significant difference in mean SBS between materials (p?=?0.004) and cement (p?=?0.001). There was also a significant interaction between method and cement on SBS, F(2,?170)?=?7.209, p?=?0.003. Post hoc Tukey tests demonstrated no significant difference for either resinmodified glass-ionomer cements (RMGIC) (p?=?0.864, p?=?0.620) when comparing non-enclosed and mould-enclosed test methods bonded to titanium. There was however a significant difference (p?<?0.001) between the mean SBS obtained for the resin cement when comparing the non-enclosed and mould-enclosed test methods. For base metal, the RMGIC’s SBS was higher than resin cement but no difference was observed between one of RMGIC’s and the resin cement non-enclosed mean SBS. Although not the case for RMGIC’s bonded to titanium or one RMGIC bonded to non-precious cobalt-based metal, when comparing the test method on each cement, RMGIC and the resin cement showed significant differences between non- and mould-enclosed specimens mean SBS. In the non-enclosed specimen tests, 71% of all specimens tested exhibited adhesive failure, which was statistically different (p?<?0.001) to 91% for the mould-enclosed specimens. Failure mode was not always statistically different within groups, however non-enclosed specimens showed higher frequencies of mixed failures. Conclusion: Within the limits of this study, significant differences were found in comparing the mean SBS between mould-enclosed and non-enclosed specimens. A significant difference was found in failure mode between mould-enclosed and non-mould enclosed specimens. Mould-enclosed specimens bonded to metal exhibited a higher frequency of adhesive failure than non-mould enclosed specimens. Relevance: Mould-enclosed specimens used in place of non-enclosed specimens can be used in SBS testing to give a more valid result when bonding to metal.     

A molecular mechanics approach to the adhesion of urea-formaldehyde resins to cellulose. Part 2. Amorphous vs. crystalline Cellulose I

The average adhesion of urea-formaldehyde (UF) resins to amorphous cellulose appears to be lower than that to crystalline Cellulose I. Water appears to be able to displace UF resins on many sites of amorphous cellulose. Selected high attraction sites appear to still be able to give adequate adhesion. There are indications that UF resins' wetting of amorphous cellulose is independent of the resin water content. The energies of interaction of UF oligomers with amorphous cellulose and Cellulose I help in distinguishing between adhesion of UF resins of different stages of condensation. It is also shown that the molecular mechanics method outlined in this article can be used to scan UF adhesive formulations as regards resin adhesion to lignocellulosic substrates.