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The article discusses the directions of development of adhesion promoters and compatibilizers for polymer–metal, polymer–fiber filler, polymer–disperse filler, and polymer–polymer systems, as well as modification of adhesives for gluing polymer materials. Among researchers, particular interest is directed towards the development of environmentally friendly promoters and compatibilizers. [ABSTRACT FROM AUTHOR]

Currently used organic coatings for the protection of bronze sculptures have a relatively short lifespan as a consequence of strict requirements of conservation ethics, which limit the selection of coatings. For that reason, enhancement of the corrosion protection level and durability of appropriate coatings is needed. The aim of this work was to examine if corrosion protection of bronze by selected acrylic and polyurethane coatings could be improved by using two phosphonic acids, 16-phosphonohexadecanoic acid (COOH-PA) and 12-aminododecylphosphonic acid (NH2-PA). Electrochemical measurements (linear polarization and electrochemical impedance spectroscopy, EIS) were performed to gain an insight into the influence of these phosphonic acids on the performance of the coatings during a two-week exposure to artificial acid rain and a three-month outdoor exposure. Besides the influence on the corrosion protection level, the influence on the coating adhesion was examined as well. A pull-off test clearly confirmed that the studied phosphonic acids act as adhesion promoters of both polyurethane and acrylic coatings, while electrochemical studies revealed improvements in corrosion protection levels, especially in the case of the acrylic coating Paraloid B72. [ABSTRACT FROM AUTHOR]

The test polypropylene substrates obtained from the original plastic car parts for Škoda Superb were subjected to 10 pre-treatment techniques: solvent cleaning (isopropanol, xylene), mechanical abrasion, immersion in a chromic acid mixture, flame activation, atmospheric and low-pressure plasma treatment, corona discharges and the application of two different primers (also called adhesion promoters). One of the primers, based on chlorinated polypropylene, was commercially available, while the other was prepared in our laboratory using polypropylene grafted with maleic anhydride. The test substrates were characterized using contact angle measurement for designation of surface free energy, Atomic Force Microscope (AFM) for roughness analysis, Scanning Electron Microscopy (SEM) for surface topography, and Energy Dispersive X-ray Spectrometry (EDX) for surface oxygen and contamination analysis. The suitability of the surface preparation methods in the industry was evaluated through peel strength tests (adhesive bonding process) and cross-cut tests (painting process). Not all tested methods were effective in increasing adhesion, especially in the adhesive bonding process, and even fewer in the painting process. However, some of them were suitable for both applications. The use of primers was found to be crucial. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of organic-inorganic (O-I) hybrid adhesion promoters, which were synthesized by an in situ sol-gel process, using alkoxysilane functionalized polymer precursor (AFAP) and other alkoxysilanes such as (3-aminopropyl)triethoxysilane (APTES) and (3-glycidyloxypropyl)trimethoxysilane (GPTMS). These adhesion promoters were then applied between polyurethane (PU) and metal substrate for improving adhesive strength between them. In particular, by modifying the input parameters including molecular structure of AFAP, weight ratios between AFAP and alkoxysilane, and r value (molar ratio of H2O/Si), the adhesive strength can be significantly improved by more than twice as high as compared to that of pristine samples without application of O-I hybrid adhesion promoters. It was reported that the combination of (3-aminopropyl)triethoxysilane (APTES) and AFAP synthesized from glycerol propoxylate (Mw = 266 g/mol) and polyethylene glycol (Mw = 300 g/mol) with high r value showed the highest adhesive strength compared to other O-I hybrid adhesion promoters. Additionally, the properties of various hybrid materials such as particle size distribution, touch drying speed, degree of condensation, molecular weight, and adhesive strength were characterized by dynamic light scattering test, 29Si-NMR, MALDI-TOF, and shear strength test. [ABSTRACT FROM AUTHOR]

A surface treatment process, named ReTreat, is presented, and is shown to enhance the adhesion of electroplated metals on Sn‐containing transparent conducting oxides (TCOs). The ReTreat process uses Zn powders, FeSO4 and glycine‐buffered aqueous solutions (pH 3 to 5) in order to regulate a controlled and uniform conversion of SnO2 surfaces to SnO, Sn metal, and FexSny alloys. These surface metallic and intermetallic layers selectively enrich the electroplating of metallic films (including Ni, Au, and Ag). Subsequently, the process has been used to fabricate thermally stable metal films on rigid FTO‐coated glass and flexible ITO‐coated PET substrates. Standardized testing confirms that the metallic coatings exhibit sufficient adhesion to the underlying TCO with high thermal stability and tolerance to flexural strain. A reaction mechanism for the heterogenous surface treatment is deduced from X‐ray diffraction, X‐ray photoelectron spectroscopy, and in situ transmittance measurements. These investigations show how the process parameters (e.g., Zn powders, FeSO4 concentration, pH, and TCO type) impact the reaction rate, morphology, and composition of the treated TCO surface. This report provides detailed insights necessary for the future implementation of this innovative surface treatment, which has the prospect to be a customary process for electroplating onto Sn‐containing TCOs. [ABSTRACT FROM AUTHOR]

Currently, in order to obtain high-tech hybrid products, modern adhesives have high requirements for creating strong joints between dissimilar materials. It is known that adhesion depends on the compatibility of the adhesives with the surfaces of the materials. Amine compounds are the main hardeners for epoxy compositions. That is why, in this article, we synthesized silicon-containing amines based on polyfunctional aminoalkoxysiloxanes for epoxy compositions. Aminoalkoxysiloxanes were prepared by the interaction of 3-aminopropyltriethoxysilane with monoethanolamine in nitrogen at atmospheric pressure in the presence of a binary antioxidant and catalytic amounts of an alkali metal alcoholate. During the reaction in a homogeneous phase, the reaction mixture was heated to a temperature of 100-110 °C and distilled off to 90% of ethanol from the theoretically calculated amount. Further, the reaction was carried out at a reduced temperature of 10-20 mmHg pressure until the release of alcohol stops. At the same time, gravimetric control was carried out and the refractive index of the reaction mixture was measured. As a result, aminoalkoxysilanes were obtained in the form of light-yellow oily liquids. The structure of the obtained compounds was investigated by IR spectroscopy on an FSM-1202 Fourier spectrophotometer and 1H NMR spectroscopy on a high-resolution BrukerWM-250 NMR spectrometer. It was found that under the selected synthesis conditions, aminopropyltri-(2-aminoethoxy)silane is obtained with the highest yield of 97.6% at a molar ratio of 3-aminopropyltriethoxysilane AGM-9 with monoethanolamine 1:3.

The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. Adhesion promoters or adhesive agents are important and proven promoters in practice. They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt’s binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt’s binder weight. Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skuteč - Litická and Bystřec quarries.

Highlights • The gauge factor of differently fabricated Pt thin films is investigated up to 500 °C. • The influence of the adhesion promoter on the electro-mechanical properties is estimated. • The microstructure and chemical composition are studied using TEM and EDX measurements. • The results are in accordance with the Tellier-Tosser-Pichard model. Abstract In this study the influence of film thickness, adhesion promoters such as chromium (Cr) and rutile titanium dioxide (TiO 2), sputtering power and substrate temperature on the electro-mechanical properties of platinum (Pt) thin films is investigated. The bilayered samples consisting of an adhesion promoter and a Pt thin film are deposited using direct current magnetron sputtering on sapphire substrates und characterized by Van-der-Pauw as well as gauge factor measurements up to 500 °C in air. Additionally, transmission electron microscopy and energy dispersive X-ray spectroscopy analysis are performed to investigate the microstructure and the chemical composition of the thin films before and after temperature loading. No substantial impact of the Pt film thickness on the electro-mechanical properties is determined. The diffusion of Cr into the Pt thin film at elevated temperatures leads to a lower gauge factor with a higher scatter range. Furthermore, higher sputtering power and substrate heating during deposition lead to a higher crystallinity of the Pt thin film and thus promote higher gauge factors. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate the effects of different adhesion promoters, namely, Enhance LC, Ortho Solo, Assure Universal Bonding Resin and deproteinizing agents such as 5.25% NaOCl, 10% papain gel on the shear bond strength of orthodontic brackets. MATERIALS AND METHOD: The present study was approved by the Ethics Committee of Teerthanker Mahaveer Dental College and Research Centre, affiliated to Teerthanker Mahaveer University, Moradabad, India. Around 150 extracted sound human upper bicuspids were taken and divided into six groups. Group 1 control (37% H3PO4), Group 2 (37% H3PO4+ Ortho Solo), Group 3 (37% H3PO4+ Assure Universal Bonding Resin), Group 4 (37% H3PO4+ Enhance LC), Group 5 (5.25% NaOCl + 37% H3PO4), and Group 6 (10% papain gel + 37% H3PO4). In all the groups (n = 150) orthodontic metal brackets were bonded with TransbondTM XT and all the samples were subjected for evaluation of shear bond strength using Instron universal testing machine at a cross speed of 0.5 mm/min. The bracket failure mode was examined using Adhesive Remnant Index (ARI). The Kruskal-Wallis test and the Mann-Whitney test were used to compare the shear bond strength. The Chi-square test was used to determine significant differences in the ARI scores among the groups. The significance for all statistical tests was P < 0.05. RESULTS: Mean values of shear bond strength showed statistically significant differences between the evaluated groups (P < 0.005). The lowest and highest shear bond strength was attributed to Group 1 (control) and Group 2 (Ortho Solo), respectively. No statistically significant difference was noted for the mean ARI scores between control, adhesion promoters, and deproteinized group (P < 0.05). CONCLUSION: It was concluded that adhesion promoters and deproteinizing agents can be used to enhance the shear bond strength of orthodontic brackets. Among all the groups Ortho Solo showed the highest bond strength when used with TransbondTM XT.

Studies have been carried out to increase the adhesion and heat resistance of insulating tape coatings based on chlorobutyl rubber applied on pipelines. It is shown that the synergistic effect of the growth of adhesion of chlorobutyl rubber to steel by the co-administration of the oligomer of 2,2,4-trimethyl-1,2-dihydroquinoline and polymeric petroleum resin is due to the increased interaction of the oligomer with chlorobutyl rubber under the action of a polymeric petroleum resin and the high adhesion of the oligomer to steel. [ABSTRACT FROM AUTHOR]

This review focuses on certain classes of organic compounds known variously in the specific literature of asphalt as adhesion promoters, antistripping agents, wetting agents, antistrips, or adhesion agents. These kinds of organic additives are currently formulated to enhance the bitumen coating of mineral aggregates and improve the workability of asphalt mixtures. In this review, the term "adhesion promoters" includes both synthetic organic compounds as well as those extracted from natural resources, mixed in trace amounts to bitumen. Their main role is to alter the interfacial energy, so that the presence of water, even in trace, does not weaken the bitumen-aggregate bond and tends to favor adhesion. The report also considers the chemical functionalities that play a predominant role in bonding, as well as the effects of surface modification of the aggregate due to the presence of adhesion promoters in pre-blended bituminous mixtures. Although bitumen is widely used in road pavement construction and the discussion is mainly addressed to the improvement of adhesion in road materials, adhesion and wetting properties can also represent a general issue in various bitumen-based industrial products. [ABSTRACT FROM AUTHOR]

This article presents results of a study on coating of a polymeric substrate ca-talyst on metallic surface. Stability of coating on metallic surfaces is a proper specification. Sol-gel technology was used to synthesize adhesion promoters of polysilane compounds that act as a mediator. The intermediate layer was coated by synthesized sulfonated polystyrene-divinylbenzene as a catalyst for production of MTBE in catalytic distillation process. Swelling of catalyst and its separation from the metal surface was improved by i) increasing the quantity of divinylbenzene in the resin’s production process and ii) applying adhesion pro¬moters based on the sol-gel process. The rate of ethyl silicate hydrolysis was intensified by increasing the concentration of utilized acid while the conden¬sation polymerization was enhanced in the presence of OH–. Sol was formed at pH 2, while the pH should be 8 for the formation of gel. By setting the ratio of the initial concentrations of water to ethyl silicate to 8, the gel formation time was minimized.

Foram avaliadas diferentes formas de glazeamento da superfície de porcelana quanto à resistência ao cisalhamento de bráquetes metálicos colados com diferentes cimentos. Quarenta e dois corpos de prova de metalocerâmica foram confeccionados (2 controles) e divididos em quatro grupos de acordo com o tipo de glazeamento, com camada extra de glaze (G) ou auto-glazeados (AG), e o cimento utilizado, resina fotopolimerizável (r) ou ionômero de vidro resinosos (i), formando os seguintes grupos: Gr, Gi, AGr e AGi com 10 corpos de prova cada grupo. Todas as superfícies dos corpos de prova receberam tratamento com ácido fosfórico 35% por 30 s seguidos de uma camada de silano. Quarenta bráquetes metálicos foram colados. Os corpos de prova foram submetidos a termociclagem e ao teste de resistência ao cisalhamento com uma máquina universal de ensaios mecânicos. Uma amostra de cada grupo após descolagem, remoção da resina e polimento, foi avaliado em microscópio eletrônico de varredura. O índice de fratura coesiva da porcelana foi também avaliado. Os resultados mostram valores acima da média aceitável na literatura para todos os grupos, sendo que o grupo AGr apresentou valor menor (10,38 MPa) e estatisticamente significativo em relação aos demais. A análise no microscópio eletrônico de varredura mostrou que as superfícies, após polimento, não readquirem as características de antes da colagem, apesar de se apresentarem aceitáveis clinicamente. Houve fratura da porcelana em todos os grupos. Conclui-se que é possível se conseguir colagem adequada de bráquetes metálicos em superfícies metalocerâmicas auto-glazeadas e com camada extra de glaze, preservando-o, não necessitando reconhecer previamente a forma de glazeamento.Different glazing techniques for porcelain surface were evaluated in terms of shear bond strength of metallic brackets bonded with different cements. Forty-two metal-ceramic samples were made (2 controls) and then divided into four groups according to type of glazing technique, either using extra glaze layer (G) or self-glazing material (SG), and type of adhesive material, that is, self-curing resin (r) or resin glass-ionomer cement (i), thus forming the following groups: Gr, Gi, SGr, and SGi with 10 samples each. The whole surface of all samples was treated with 35% phosphoric acid for 30 s, followed by application of silane layer. Forty metallic brackets were bonded. The samples were submitted to thermocycling process and shear bond strength test with a universal testing machine. After bracket debonding, removal of resin, and polishing, one sample from each group was evaluated with a scanning electron microscope (SEM). The index of cohesive porcelain fracture was also assessed. The results show that all the groups had, on average, values higher than those found in the literature, with AGr presenting the lowest value (10.38 MPa) compared to other groups. SEM analysis showed that the porcelain surfaces did not recover their original characteristics before the bracket debonding procedure, although they were considered acceptable for clinical use. Porcelain fracture was observed in all groups. One can conclude that it is possible to bond metallic brackets adequately to metal-ceramic porcelain surfaces previously treated with either self-glazing material or extra glaze layer without having to recognise the glazing technique originally employed.

The mixtures of elastomer compounds based on natural and 1,4-cispolybutadiene rubber of 80:20 ratio, were used for the investigation of adhesion promoters influence on adhesion of vulcanisate to steel cord. Ni-stearate and resorsynol-formaldehyde resin combined with hexamethylenetetramine in various mass ratios were included as adhesion promoters. Elastomer mixtures were prepared using a laboratory double mill, and the rheological and vulcanization characteristics were examined on a vulcameter provided with an oscillating disc, a higher temperature of 145 °C. The crosslinking of the mixture was carried out by press, at a temperature of 145 °C and specific pressure of 40 bar, in period of 45 minutes. A wide number of standardized methods for physical mechanical characterization of vulcanization prior and after accelerated aging were used. The adhesion of vulcanizate bond with zinc coated steel cord was determined according to the so called H-test, by measuring the pulling-out force of the cord from the vulcanized block, and the degree of coverage of cord with vulcanizate after separation. The results of examinations show significant dependence of physico-mechanical characteristics and adhesion forces on the type and amount of used adhesion promoters in experimental elastomer mixtures.

This review focuses on certain classes of organic compounds known variously in the specific literature of asphalt as adhesion promoters, antistripping agents, wetting agents, antistrips, or adhesion agents. These kinds of organic additives are currently formulated to enhance the bitumen coating of mineral aggregates and improve the workability of asphalt mixtures. In this review, the term “adhesion promoters” includes both synthetic organic compounds as well as those extracted from natural resources, mixed in trace amounts to bitumen. Their main role is to alter the interfacial energy, so that the presence of water, even in trace, does not weaken the bitumen-aggregate bond and tends to favor adhesion. The report also considers the chemical functionalities that play a predominant role in bonding, as well as the effects of surface modification of the aggregate due to the presence of adhesion promoters in pre-blended bituminous mixtures. Although bitumen is widely used in road pavement construction and the discussion is mainly addressed to the improvement of adhesion in road materials, adhesion and wetting properties can also represent a general issue in various bitumen-based industrial products.

[Display omitted] • Self-adhesive smart films that can adhere to existing glazing are prepared. • PET film, thermotropic hydrogel, and acrylic adhesive are covalently assembled. • Smart film can be easily installed and removed without leaving any residue. • Optical switching for active solar control is fully reversible and repeatable. • Switching temperature can be finely tuned for various climate conditions. Energy conservation has become a crucial concern for reducing carbon dioxide emissions; thus, smart windows that selectively control incident solar radiation are attracting considerable attention. While extensive research has worked towards rendering the adaptive modulation of optical transparency, the wide application of traditional glass-type smart windows is limited by their high-cost installation that requires the removal of existing glazing. In this work, we report the preparation of a smart film that can be easily attached to any surface shape. A multilayer smart film comprising a transparent polyethylene terephthalate substrate, a thermotropic poly(N -isopropylacrylamide) (PNIPAm) hydrogel, an acrylic adhesive, and a release film was prepared based on robust interface chemistry to ensure its stability. Field tests for optical switching between transparent and opaque states were demonstrated in response to the outdoor temperature. Furthermore, the developed smart film could be cut into specific shapes, namely letters, and attached to glass windows, indicating its potential to display various forms of information. The switching temperature could be finely tuned for various climatic conditions by copolymerizing the PNIPAm hydrogel with hydrophilic or hydrophobic comonomers. In addition, the attached film can be easily removed on demand without leaving any residue. [ABSTRACT FROM AUTHOR]

Brief Introduction: This study was done to determine the effect of 2 adhesion promoters: Enhance L.C. (Reliance) and Ortho Solo™ (Ormco) on the shear bond strength of new and recycled orthodontic brackets and the amount of remnant adhesive on the teeth after debonding. Materials and Methods: Sixty new and sixty recycled brackets were bonded to 120 extracted human premolars with composite resin and divided equally into 6 groups based on the 2 adhesion promoters used: (1) New brackets/no adhesion promoter, (2) Recycled brackets/no adhesion promoter (3) New brackets/Enhance L.C. (4) Recycled brackets/Enhance LC (5) New brackets/Ortho Solo™ (6) Recycled brackets/Ortho Solo™. Statistical analysis used: Comparision of shear bond strength was done by Kruskal-Wallis and for inter group multiple comparison Mann-Whitney was performed. The chi-square (x2) test was used to determine significant differences in the ARI scores between the different groups. Significance for all statistical tests was predetermined at P < .05. Results: New brackets/OrthoSolo™ (Group V, 13.151 ± 0.932) had the highest shear bond strength followed by New brackets/Transbond XT (Group I, 11.491 ± 1.72) > New brackets / Enhance L.C. (Group III, 11.069 ± 1.538) > Recycled brackets/OrthoSolo™ (Group VI, 8.255 ± 0.725) > Recycled brackets/Enhance L.C. (Group IV, 7.103 ± 0.898) > Recycled brackets/Transbond XT (Group II, 6.777 ± 0.539). Conclusions: Recycling brackets with Ashpol electropolishing liquid can serve them as new brackets in terms of the clinically acceptable bond strength. [ABSTRACT FROM AUTHOR]

The products of interactions between glycidyl ester of methacrylic acid and aniline were used as modifiers for chlorosulfonated polyethylene adhesives providing an enhanced strength of adhesive joints between vulcanized rubbers. [ABSTRACT FROM AUTHOR]

The dependence of the strength of rubber-metal bonds on different methods of their preparation is considered. Methods of hot and cold bonding of rubbers are described. The effect of different technological factors on the strength of rubber-metal bonds is analyzed. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: This study was done to determine the effect of 3 adhesion promoters: Ortho Solo™ (Ormco), ALL-BOND 2® (Bisco), and Enhance L.C. (Reliance) on the shear bond strength of new and recycled orthodontic brackets and the amount of remnant adhesive on the teeth after debonding and to verify whether Enhance L.C. is material specific as stated by the manufacturer. Materials and Method: This in vitro study was carried out on 120 premolar teeth which were bonded to 0.018 Roth premolar brackets. These teeth were divided into 6 groups of 20 with 2 subgroups—new group and recycled group. Brackets were bonded according to manufacturer''s instructions: [1)] Transbond™ XT [2)] Transbond™ XT+ALL-BOND 2® [3)] Transbond™ XT + Ortho Solo™ [4)] Transbond™ XT + Enhance L.C. [5)] Light Bond™ [6)] Light Bond™ + Enhance L.C. Bond strength was tested on a universal testing machine and remnant adhesive on the tooth surface was determined. Kruskal-Wallis test and Mann-Whitney test were carried out to know the significant difference between the groups. Chi-square test was used to determine significant differences in the Adhesive Remnant Index (ARI) scores between the scores. Weibull analysis was performed to know the percentage of bracket failures among the groups tested. Results: There was no significant difference between the groups with respect to the median load (p<0.001). Higher mean load was recorded in Group Via (Light Bond™ + Enhance L.C.) and least in Group lb (recycled with Transbond™ XT). Chi-square test showed no significant association between the ARI scores and the different groups. Conclusion: Recycling brackets with Ashpol electropolishing liquid can serve them as new brackets in terms of the clinically acceptable bond strength. It is preferable to use Enhance L.C. with Light Bond™ when greater bond strength is required with new brackets. [Copyright &y& Elsevier]

Long-term durability of a structural adhesive joint is an important requirement, because it has to be able to support the required design loads, under service conditions, for the planned lifetime of the structure. Epoxy adhesives, whilst not ideal, are currently the best family of adhesives for in situ repair operations. As long as the bonded joint remains dry and unexposed to high service temperatures, epoxy adhesives produce strong bonds to timber. However, once they are exposed to severe stresses as a result of repeated water soaking and drying cycles, the bonded joint delaminates and does not fulfill the requirements for structural timber adhesives intended for exterior exposure. One way of improving bond durability is through the use of surface treatments prior to bonding. In this study, the effects of corona discharge surface treatment, hydroxymethylated resorcinol (HMR) and γ-glycidoxypropyltrimethoxysilane (GPMS) adhesion promoters on the durability enhancement of pine, iroko, and oak bonded joints were evaluated. The results proved that surface modification methods for adhesion promotion can be adapted to cellulosic substrates with significant improvements in bonded joint durability. [ABSTRACT FROM AUTHOR]

The article presents a study on the effects of the different glazed ceramic surfaces on the bond of orthondontic brackets. The study uses scanning electron microscope (SEM) to evaluate sample from each group after bracket debonding, removal of resin, and polishing. The result shows that the porcelain surfaces did not recover their original characteristics before the bracket debonding procedure, although they were considered acceptable for clinical use.

The use of primers, coupling agents, and other surface treatments to enhance adhesion is now common in the aerospace, automotive, and plastics industries, where they are used to develop highly durable bonds to metals, advanced composites, ceramics, and plastics. However, such treatments are virtually non-existent in the wood products industry although they could solve important adhesion problems. In particular, adhesion promoters can enhance the environmental durability of epoxy bonded joints, and they can enhance the reliability of bonds to timber treated with wood preservatives. A review of current findings is provided that attempts to gather the scarce and disperse information available in the literature about adhesion promotion techniques for bonded solid timber joints. A general overview of the research needs on this topic is also given. [ABSTRACT FROM AUTHOR]

The stability of epoxy/glass interfaces subjected to hygrothermal aging was assessed using a fracture-mechanics approach. An epoxy system consisting of diglycidyl ether of bisphenol F cured with 2-ethyl-4-methyl-imidazole was bonded to borosilicate glass adherends that were treated with various types of adhesion promoters to provide a variety of interfaces. Adhesive strength was measured under dry, as-processed conditions and as a function of exposure time to an 85°C/85% relative humidity (RH) environment. As expected, the strain-energy-release rate, G c , dropped significantly with aging time for the bare epoxy/glass interface. The drop in G c is assumed to be due to a loss of interfacial forces. The use of two silane-based adhesion promoters, 3-aminopropyltriethoxysilane (APS) and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (ECH) resulted in improved adhesive strength both before and after hygrothermal aging. The improvement in adhesive strength can be explained by the introduction of chemical bonds at the interface. The drop in G c is assumed to be due to a loss of interfacial forces and hydrolysis of siloxane bonds. In addition to the use of organosilane-based adhesion promoters, a series of polyhydroxyaminoethers (PHAE) thermoplastic adhesive resins was also investigated as potential adhesion promoters. It was found that 2% PHAE in Dowanol® PM, a hydroxyl-group-containing solvent, was the best system for the PHAE-based adhesion promoters. Interestingly, both the acetic acid concentration in the solvent and maleic anhydride content in the PHAE resin were shown to affect the adhesive strength. [ABSTRACT FROM AUTHOR]

On the basis of literature data the problems concerning the methods of surface preparation and use of interlayer in the preparation of tough durable and resistant elastomer/metal joints are presented. New methods of preparation and modification of superficial layer and surface of a metal were presented -- such as: phosphatizing, plasma or laser treatment of the metal surface, metal plating with interlayer of Cu,Ni, ZnCo or ZnNi alloys or plasma acetylene polymer as well as the coating with bifunctional silanes especially the mixture of bis(trimetoxysilylopropyl)amine with bis(trimetoxysilylopropyl) tetrasulfide. Preparation of metallic or nonmetallic interlayers as well as pro-adhesive substances used, showing good adhesion to both joining components, and adhesion promoters were described. Modified phenol-formaldehyde resins and chlorinated polyolefins as well as waterborn adhesive systems containing reactive polar polymers as new components of adhesive systems for metal surface coating were presented. Attention has been paid to resorcinol-formaldehyde and melamine resins as the mixtures' components and their use with new adhesion promoters from the groups of Co, Ni, Mo or Zr naphthenates or carboxylates, including higher fatty acids, Zn or Mg methacrylates, elastomers functionalized with epoxy, anhydride or carboxylic groups increasing the adhesion of crosslinked elastomers tometals. The factors influencing the characteristics of elastomer/metal joints and directions of searching of ideal technological solutions of such joints were pointed. [ABSTRACT FROM AUTHOR]

Adhesion of organic coatings to thermoplastic olefin (TPO) substrates in automotive applications has been an issue for makers of automotive parts since TPO was first used in exterior applications, primarily fascia. A widely used technique for assuring paint adhesion to TPO is the use of adhesion promoter primers based on chlorinated polypropylenes (CPO). Much research has been focused on understanding the forces involved at the interfaces of substrate, adhesion promoter, and topcoats resulting in the adhesion or the loss of adhesion in various environmental conditions. This study correlates the adhesion performance of CPO and nonchlorinated adhesion promoters (NCPO) as measured by peel strength with properties observed through microscopy techniques. Adhesion performance of CPOs, NCPOs, and blends are quantified through the use of 90° and 180° peel strength studies. Surface characteristics of adhesion promoters applied over a TPO substrate and cured at various temperatures are examined through the use of atomic force microscopy (AFM). [ABSTRACT FROM AUTHOR]

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Nanoscale analysis may be used to design new types of mucoadhesive polymers. Understanding of the surface interactions between hydrophilic polymer surfaces and mucins can lead to improved adhesive bonding by hydrogen bonding. Alternatively, decoration of a mucoadhesive polymer surface with tethers of linear and block copolymers containing neutral or ionizable structures provides increased interdigitation and interpenetration with the mucus. Finally, formation of micro- or nanopatterns on these surfaces can lead to promising new systems of oral delivery applications. [Copyright &y& Elsevier]