鞋用PVC处理剂研究

ＣＲ／ＣＰＥ／ＭＭＡ／ＨＥＭＡ四元接枝共聚物经溶剂稀释而成的溶液是很好的ＰＶＣ表面处理剂，它的使用极大地提高了氯丁接枝胶对ＰＶＣ鞋材的粘结性能。可五接枝胶配套使用，广泛用于制鞋。     

Waterproofness Results for the Surface Treatment of Heavy-Duty Leather for Adhesion Enhancement

This article presents further work undertaken in respect to the use of specific primers for adhesion on leather surfaces. This research focused on the use of photoreactive reagents and silane networks as primers and investigated their roles in seam strength and resistance against water ingress. A specific waterproof test was undertaken on treated samples in accordance with EN ISO 5403:2002. Samples treated with 4-(2,2′-iminodiethanol)-3-nitrophenylazide (azide 4) when primed only on one side of the test panel showed good resistance to water ingress. Samples treated with 3,5-dihydroxyphenyl-4-azidobenzoate (azide 7) or 3-(2-aminoethylamino)propyltriethoxysilane (AEAPES) on both sides of the test panels resulted in a seam that did not fail. However, double side treatment with these reagents generated a thicker glue line than single side treatment, which might present practical problems in terms of the flexibility of the resultant assembly during its life cycle.     

Bonding of vapor deposited gold to glass using organosilane primers

Organosilane primers are known to improve adhesion of thin metal films deposited on inorganic and plastic surfaces. The present study demonstrated that the initial peel adhesion of vapor deposited gold to silane-primed glass substrate is greater than 3.5 N/cm estimated from cross-hatch test and thus is generally consistent with the earlier reports. The gold coated glass slides when examined using a more severe test (i.e. chemically bonding to a polymer, and subsequent peeling), however, exhibited poor adhesion in all cases except when the glass substrate was primed with an oligomeric organosilane primer. The successful primer (Dow Corning® 1205) was found to develop peel adhesion between vapor deposited gold and glass which was better than 17.5 N/cm.     

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.     

A SVET investigation on the modification of zinc dust reactivity

Weldable primers are thin zinc-rich organic coatings that are weldable due to the electrical conductivity provided by the zinc dust. They are used in the automotive industry to provide corrosion protection in regions of difficult access. The zinc particles are highly susceptible to corrosion attack and, due to the small thickness, the protection conferred by these systems is limited.     

Reduction of zinc and volatile organic solvents in two-pack anti- corrosive primers, a pilot study

For decades one of the directions to obtain anti-corrosive properties of coatings in the protective coating industry has been the use of zinc as an active pigment in the primer layer. However due to strengthening of environmental legislation the use of this metal has become an item of discussion. In addition due to the nature of the traditional low solid zinc containing formulations, formulated close to critical pigment volume concentration (PVC), it proved to be difficult to develop very high solids zinc containing formulations with comparable performance. At the moment the product range of our company contains both zinc containing and zinc free two-pack primers. Examples from both generic types have excellent track records. To determine the position of the zinc free primers in relation to the zinc containing ones a comparison study was initiated. A new high solids two-pack epoxy primer was included in this test program to check whether a solvent reduction in this range of products was feasible. In this paper the results of the comparison between a zinc epoxy primer, a zinc free epoxy primer and a high solids version of the zinc free epoxy primer, some formulation aspects and the consequences for the future will be discussed.     

Inorganic primers in bonded joints

An amorphous aluminium oxide coating, generated from aluminium chelate or alkoxide compounds, has been investigated as a primer for adhesively bonded phosphoric acid anodized 2024 aluminium adherends. Tensile lap shear and T-peel specimens were used to evaluate the effect of the alumina-coated surfaces on the mechanical properties of the bonded joints. Equivalent wet and dry tensile lap shear and T-peel bond strenghts were obtained when the inorganic coating was substituted for the normally used organic primer. Transmission and scanning electron microscopy of the alumina-primed surfaces showed that the oxide honeycomb/protrusion morphology resulting from phosphoric acid anodizing was infiltrated by the solution-deposited inorganic primer to produce a low profile bonding surface.     

Modification of zinc powder to improve the corrosion resistance of weldable primers

This paper reports the modification of zinc powder to improve the corrosion resistance of weldable primers. These primers are thin zinc rich organic coatings applied by roll coating at the steel manufacturer. The automotive industry uses them to protect areas in the car body that become inaccessible after joining processes. In this work, with the objective of increasing the corrosion resistance of these systems, the zinc particles were chemically treated or simply replaced by powder of 55AlZn alloy. The rest of the formulation remained intact. The performance of the commercial and modified formulations was compared by SEM, SVET and EIS. The best results were obtained when the zinc powder was replaced by powder of the aluminium zinc alloy.     

Chemical interactions in the system anodized aluminum—primer—adhesive

Chemical interactions in the primed aluminium/adhesive interphase were examined using IR reflectance spectroscopy. For the case of epoxy primers and polyurethane adhesives, a new absorption was detected and was attributed to an isocyanate group, formed by reaction between the epoxide primer and the polyurethane adhesive. When polyurethane adhesive was applied on a polyurethane primer, such a primer-adhesive interaction was not noticed.     

Evaluation of primers for adhesively-bonded aircraft repair

This paper contains the results of an investigation to determine the effectiveness of primers in promoting adhesion and improving the environmental durability of epoxy adhesive bonds on grit-blasted aluminum substrates. The control for this study consisted of phosphoric acid anodization of substrates followed by the application of EC 3924 B primer. The following primers were evaluated on grit-blasted substrates: (1) EC 3924 B; (2) Metlbond 6726; (3) Dow Corning Z-6040; and (4) EA 9203. In addition, grit blasting followed by Alodine application was compared with the other primers. Studies include shear strength evaluations of each primer/adhesive system at 23 and 105°C. In order to assess the relative durability of each system, shear strength testing at 93°C of samples exposed for 2 weeks to a 93°C/condensing humidity environment and wedge crack extension testing of samples exposed for a 2-week period to a 60°C/condensing humidity environment were performed. The peel strengths of the systems were determined by conducting floating roller peel studies at -55, 23, and 105°C. Statistical analysis of the data revealed that the level of performance provided by EC 3924 B, solvent-borne, corrosion inhibiting control primer on phosphoric acid-anodized surfaces exceeded that of all the primers on grit-blasted substrates. However, when comparing the primers applied after only a grit-blast treatment, y-glycidoxypropyltrimethoxysilane primer showed statistically better results than the other primer systems.     

新型弹性丙烯酸聚氨酯玻璃钢底漆的研制

以弹性丙烯酸树脂和HDI聚合物为成膜物制得双组分玻璃钢专用底漆,经测试其各项性能达到设计要求.研究发现:不同官能度的HDI聚合物固化剂对涂料的力学性能和施工性能有影响,但对耐化学品和耐久性影响不大;带亲颜料基团的高分子嵌段共聚物分散剂对漆料的研磨效率和贮存稳定性贡献要大于氨基聚酯型分散剂;有机改性膨润土和气相二氧化硅比聚乙烯蜡浆对涂料喷涂施工厚度提高效果要明显.     

Effects of Silanes Alone and Their Blends with HEMA on Resin–Titanium Bonding

Abstract

Two organofunctional silane coupling agents alone and two silane blend systems with HEMA were evaluated in vitro as adhesion promoters for bonding bis-GMA resin to a silica-coated titanium surface. The silanes were applied onto tribochemically silica-coated titanium surfaces. Experimental bis-GMA resin stubs were applied and photo-polymerized onto titanium. The specimens were subjected to three different conditions: (1) dry storage for 24 h, (2) storage in de-ionized water at 37°C for six months and (3) alternating storage in de-ionized water at 37°C and thermocycling (6000 cycles, 5–55°C) for 6 months. Shear bond strengths of the resin to titanium were measured using a universal testing machine. Surface examination was made with a scanning electron microscope (SEM) after the bond strength test. Highest shear bond strength was obtained with 3-acryloxypropyltrimethoxysilane stored in dry condition (20.2 ± 3.2MPa), and the lowest value was obtained with 3-methacryloxypropyltrimethoxysilane (ESPE Sil) in alternating water storage and thermocycling condition (1.4 ± 0.6 MPa). The type of storage condition affected significantly the shear bond strength (p < 0.05). The shear bond strength obtained from dry storage was the highest, while the shear bond strength obtained from alternating water storage and thermocycling condition was the lowest. Interfacial failure was the main failure mode (87.2%) followed by mixed failure (9.4%) and cohesive failure (3.4%). The addition of 0.5 vol%. HEMA into silane primers did not improve the shear bond strength between the experimental resin and silica-coated titanium.     

Adsorption of Model Adhesive Compounds onto Plasma-Polymerized Silica-Like Films

Plasma-polymerized silica-like primer films on aluminum substrates were prepared and exposed to diethanolamine (DEA), a model adhesive compound, from dilute solution. Reflection-absorption infrared (RAIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to investigate the chemical interactions between the adsorbed compound and the substrate. RAIR spectroscopy showed significant changes in the structural chemistry of the silica-like films after exposure to ethanol with and without DEA. Although no evidence of adsorption was observed in the infrared spectra, XPS indicated that a small amount of model compound did adsorb onto the surface of the silica-like film. The N(1s) photoelectron spectra of the adsorbate showed two components; one was typical of the bulk amine, and the other indicated that the amine group of the adsorbed model adhesive had chemically interacted with the substrate. The adsorbate/substrate interaction strength was also examined by heating the sample in ultra-high vacuum (UHV) and observing the temperature at which desorption occurred. The sample was heated to 250°C for several hours and no desorption was detected. It was concluded that protonation of the amine group had occurred forming a quaternary ammonium ion. It was also likely that bonding between the alcohol functionality and the silica surface added to the adsorption strength.     

Corrosion resistance of new epoxy–siloxane hybrid coatings. A laboratory study

Traditional multilayer epoxy/polyurethane type anticorrosive paint systems are widely employed in the protection of steel structures due to their high efficiency against atmospheric corrosion. However, the use of isocyanate in the curing process, and the high volatile organic compound (VOC) content of such systems, makes it necessary to search for new isocyanate-free paints.     

Adsorption of Model Adhesive Compounds onto Plasma-Polymerized Silica-Like Films

Plasma-polymerized silica-like primer films on aluminum substrates were prepared and exposed to diethanolamine (DEA), a model adhesive compound, from dilute solution. Reflection-absorption infrared (RAIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to investigate the chemical interactions between the adsorbed compound and the substrate. RAIR spectroscopy showed significant changes in the structural chemistry of the silica-like films after exposure to ethanol with and without DEA. Although no evidence of adsorption was observed in the infrared spectra, XPS indicated that a small amount of model compound did adsorb onto the surface of the silica-like film. The N(1s) photoelectron spectra of the adsorbate showed two components; one was typical of the bulk amine, and the other indicated that the amine group of the adsorbed model adhesive had chemically interacted with the substrate. The adsorbate/substrate interaction strength was also examined by heating the sample in ultra-high vacuum (UHV) and observing the temperature at which desorption occurred. The sample was heated to 250°C for several hours and no desorption was detected. It was concluded that protonation of the amine group had occurred forming a quaternary ammonium ion. It was also likely that bonding between the alcohol functionality and the silica surface added to the adsorption strength.     

Evaluation of anti-corrosive pigments by pigment extract studies, atmospheric exposure and electrochemical impedance spectroscopy

The inhibition efficiencies of zinc chromate, barium metaborate, calcium silicate, amino carboxylate, calcium barium phosphosilicate, aluminum triphosphate and a modified zinc phosphate on the corrosion of steel and zinc were determined by polarization experiments on pigment extracts. Zinc phosphate and zinc chromate were the best and were studied further to determine the effect of pH and chloride concentration on their inhibition of steel. Zinc chromate is adversely affected by high concentration of chloride ions, which effect seems to be less pronounced on zinc. A low pH, although increasing the solubility of zinc phosphate, does not increase its efficiency. The pigments were also incorporated into an epoxy-poly(amide) binder, applied to cold-rolled steel and galvanized steel, exposed at a marine exposure station and the degradation monitored by electrochemical impedance spectroscopy. There was a general correlation between the results of pigment extract studies and atmospheric exposure except in the case of phosphate pigments on cold rolled steel.     

基因芯片的PCR引物设计

基因芯片（Gene chip),将大量特定的核苷探针有序地固定在玻璃或硅等基底上，通过检测探针与荧光标记的核酸靶序列发生杂交显示的信号，获得生命信息，PCR技术可扩增核酸靶序列，极大提高了检测灵敏度，进行PCR扩增的首要条件是设计人工合成的寡核苷酸引物，本文介绍了PCR引物设计软件的一般设计原理并设计了相关软件。     

catA Gene in a Potential Corynebacterium Strain is Responsible for its Efficiency in Phenol Bioremoval

Out of 10 bacterial strains isolated out of wastewater of a pharmaceutical industry the most efficient bacterium, which could tolerate 5,000 mgl^?1 of phenol in the minimal medium, was identified to be Corynebacterium sp.DST1 through 16S rDNA analysis. This strain could remove 99.4% of phenol from the minimal medium containing 4,000 mgl^?1 of phenol. The ortho catalytic pathway using the enzyme catechol 1, 2- dioxygenase was found to be the major pathway for phenol degradation in the bacterium. The gene for catechol 1, 2-dioxygenase (catA) could also be amplified using degenerate primers. Corynebacterium sp.DST1 cells were attached to sawdust and removal of phenol from industrial effluents was evaluated. About 92.7% of phenol could be removed from the effluent of a heavy electrical industry. The results of this study not only suggest the potentiality of the strain to remove phenol efficiently from crude industrial effluents but also display a cheap method of bioremediation using sawdust.     

Infrared and X-ray photoelectron spectroscopy of aminophenyltrimethoxysilane films on metals

The molecular structures of thin films formed by aminophenyltrimethoxysilane (APTMS) deposited onto mechanically polished aluminum, iron, and copper substrates from dilute aqueous alcohol solutions were determined using reflection-absorption infrared spectroscopy (RAIR) and X-ray photoelectron spectroscopy (XPS). The as-deposited films on all three substrates were similar and consisted of hydrolyzed oligomers that condensed to form siloxane polymers during heating at elevated temperatures. APTMS films on all three substrates reacted readily with epoxy resins at 150°C. Although some loss of nitrogen was observed, the films formed on aluminum were relatively stable during heating at 250°C and inhibited oxidation of the substrate. The films formed on iron and copper depolymerized rapidly during heating at 250°C and failed to inhibit oxidation of the substrates. It was concluded that APTMS films were potentially useful primers for use at high temperatures on aluminum, but not on copper or iron.     

The application of multiscale quasi 4D CT to the study of SrCrO4 distributions and the development of porous networks in epoxy-based primer coatings

Transport paths for inhibitor release within a model strontium chromate (SrCrO₄) inhibited/epoxy primer have been studied using a combination of tomography techniques. It has been found that the SrCrO₄ particles form independent clusters within the model primer. The clusters have a range of fractal dimensions with the largest clusters (a few hundred microns in size) having a fractal dimension of 2.36. Leaching of the SrCrO₄ from the primer appears to be initially through direct dissolution of particles in contact with the electrolyte but changes to diffusion through void pathways created by dissolution of the SrCrO₄ phase. No evidence was found for the diffusion of chromate ions through the epoxy. Transport through such clusters does not follow Fickian diffusion, which has traditionally been employed to describe inhibitor release dynamics. Release kinetics typically follow a t^m behaviour where t is time and m is an index which would be 0.5 for Fickian diffusion. Thus the overall release with time will evolve, being initially the result of direct dissolution, then at intermediate times, be dominated by transport through the fractal network and at the final stage go to zero since all the strontium chromate will be dissolved from the cluster connected to the surface. Clusters not connected to the surface remain undissolved and form additional reservoirs for further release in when local damage occurs in their vicinity. This new model of inhibitor transport creates new strategies for the development of self-healing properties for coatings.