The effect of moisture on the strength of polycarbonate-cyanoacrylate adhesive bonds

The effect of humid ageing on the bond strength of polycarbonate-polycarbonate and steel-steel joints bonded with cyanoacrylate adhesive has been investigated. The superior moisture resistance of the bond between the polymer adherends has been demonstrated. The improved stability can be attributed to the dissolution of the polycarbonate in the monomer during curing. The bond produced has no true adherend/adhesive interface. This prevents the entry of water into the joint and consequently precludes effects such as adhesive displacement or hydrolysis of the cured polymer.     

The effect of moisture and temperature on the properties of an epoxide-polyamide adhesive in relation to its performance in single lap joints

A template cutting technique has been used to prepare dumb-bell shaped specimens of the epoxide-polyamide adhesive FM 1000, and their mechanical properties have been examined as a function of water exposure, testing speed, and temperature. The glass transition temperature of the wet adhesive has also been examined. Strengths of single lap joints bonded with the adhesive have been measured after exposure to warm moist air for up to 2500 hours. Strengths of wet and dry joints have been compared over a wide temperature range. The results show that the weakening effect which water has is due to plasticization of the adhesive, and that the rate of weakening depends on water diffusion within the adhesive layer.     

The effect of primers on adhesive properties and strength of adhesive joints made with polyurethane adhesives

The paper presents selected aspects of the effect of primers on adhesive properties and strength of aluminium sheet adhesive joints, made using polyurethane adhesives. The strength of adhesive joints was determined based on two cure time variants: 15 and 64 h. It was found that the longer cure time at a humidity of 33% is more desired, as it leads to a substantial increase in strength of the tested adhesive joints. In addition, two variants of surface preparation were applied: degreasing and degreasing followed by the application of a primer (a pro-adhesive agent). It was observed that the primer application prior to the application of an adhesive leads to a significant increase in strength compared to the variant where the adhesive application is preceded only by degreasing. Moreover, the aluminium sheet surface that was subjected to cataphoretic painting and priming exhibits better adhesive properties. It has a higher value of both surface free energy and its dispersion and polar components compared to the surface that was only subjected to degreasing.     

Effect of different adhesive protocols on bond strength between composite resins for indirect use and repair materials

Abstract

The aim of this work is to evaluate the effect of different adhesive protocols on the bond strength (SBS) of composite resin for indirect use to repairs of bulk-fill or conventional nanoparticulated composites. Forty-eight cylindrical specimens of composite resin for indirect use were prepared, aged, and randomly divided into four groups (n?=?12), a control group without any adhesion protocol, and three experimental groups: Silane?+?Scotch Bond Multipurpose adhesive (S?+?SBMP), Tetric N Bond Universal (TBU), and Single Bond Universal (SBU). The treated surfaces were restored using two different composite resins: Filtek Bulk-Fill or Filtek Z350XT. Then, the specimens were submitted to the SBS test, and the resultant data were analyzed with ANOVA on ranks test and Tukey’s test (α?=?0.05). There were no significant differences between the two types of resins used as repair material. For both resins, the groups treated with S?+?SBMP obtained the highest values (p?<?0.001). Groups TBU and SBU did not have statistically significant differences between them. Pre-treatment with a silane coupling agent and a layer of a hydrophobic adhesive can improve the bond strength of repairs performed on a composite resin for indirect use.     

The shear bond strength of repaired high-viscosity bulk-fill resin composites with different adhesive systems and resin composite types

This study compared the effect of different adhesive systems and composite resins on the shear bond strength (SBS) of repaired high-viscosity bulk-fill composites(Tetric EvoCeram Bulk Fill) and investigated failure modes. One hundred twenty cylindrical bulk-fill composite blocks (diameter 5?mm) were fabricated and thermocycled for 5000 cycles (5–55?°C). Specimens were roughened by diamond bur and divided into 8 groups (n?=?15). Bulk-fill blocks were repaired with the same material or nanohybrid composite resin(Tetric EvoCeram Nanohybrid) (diameter 3?mm) using different adhesive systems:Tetric N-Bond Universal (TSE);37% phosphoric acid etching?+?Tetric N-Bond Universal (TER); Clearfil SE Bond (CSE); 37% phosphoric acid etching?+?Adper^TMSingle Bond 2(SB). After repair procedures, all specimens were thermocycled again. The shear bond strengths were measured for all specimens using a universal test machine (crosshead speed of 1?mm/min). Cohesive strengths of bulk-fill composites were measured and described as control group. Debonded surfaces were observed with a stereomicroscope under 10x magnification to determine mode of failure. The SBS data of all groups was statistically analyzed by two-way ANOVA and Bonferroni correction test (p?<?0.05). The specimens repaired with bulk-fill composites showed significantly higher SBS values (25.86?±?5.74, 27.05?±?4.93, 24.49?±?6.95MPa) than those with nanohybrid composites (20.41?±?3.70, 22.08?±?6.37, 18.74?±?6.40?MPa) for TER,CSE,SB, respectively (p?<?0.05). There were no significant differences in SBS according to the type of adhesive systems for both repair materials (p?>?0.05). The predominant mode of failure was a mixed type in the restorative material except for the ones repaired with nanohybrid composites using Adper^TMSingle Bond 2. High-viscosity bulk-fill composites could be successfully repaired with the same materials. SBS of repaired bulk-fill composites reached cohesive strength for all tested groups.     

Incorporation of EGCG into an etch-and-rinse adhesive system: mechanical properties and bond strength to caries affected dentin

This study evaluated how a matrix metalloproteinase (MMP) inhibitor (EGCG) incorporated into an etch-and-rinse adhesive system (AS) affects the long-term microtensile bond strength (MTBS) to caries affected dentin (CAD) and flexural strength (FS) of AS. Forty CAD surfaces received acid conditioning and were randomly divided into four groups (n?=?10): EGCG-PRE – dentin treatment with 200?μg/mL EGCG solution; EGCG-INC – 200?μg/mL EGCG solution incorporated into SA; CHX-PRE – dentin treatment with 2% digluconate solution; NT – no treatment. The AS (Adper Single Bond 2, 3M ESPE) was applied and resin composite blocks were built on the dentin. Beam-shaped specimens (0.8?mm²) were obtained submitted to MTBS testing following 24?h, 6 months or 1 year of water storage (WS). Adhesive interface was analyzed by SEM. FS testing was performed by preparing specimens with the adhesive system, with or without the EGCG solution (200?μg/mL) (n?=?10). Tests were carried out in a universal machine (0.5?mm/min). MTBS data were submitted to two-way ANOVA and Tukey’s test, whereas FS data, to the Student’s t-test (α?=?0.05). MTBS values were not affected by EGCG application, either incorporated or used as a dentin treatment agent, regardless of the WS period; however, CHX negatively affected MTBS to CAD (p?<?0.001). WS significantly reduced MTBS values (p?<?0.001) from the 6-months time point. FS was not affected by EGCG incorporation into the SA (p?=?0.2527). EGCG incorporation into AS was unable to maintain bond stability to CAD over time, whereas it did not compromise adhesive’s property.     

The influence of retention hole and adhesive systems on the shear bond strengths of resin composite to amalgam

The aim of the study is to evaluate the influence of surface-treatment methods with and without the use of a retention hole on the shear bond strength of a resin composite adhered to amalgam using an adhesive system. Amalgam specimens were divided into six groups. Group 1 (Bur) specimens were roughened with a diamond bur, Group 2 (Al₂O₃) specimens were sandblasted with a 50?μm aluminum oxide powder, Group 3 (CoJet^®) specimens were sandblasted with 30?μm CoJet^® Sand, Group 4 (Bur?+?Rh) specimen surfaces were prepared with a retention hole 1?mm in diameter and 1?mm deep and roughened with a diamond bur, Group 5 (Al₂O₃?+?Rh) specimens were also prepared with a retention hole and sandblasted with 50?μm aluminum oxide powder, and Group 6 (CoJet^®?+?Rh) surfaces were prepared with a retention hole and sandblasted with 30?μm CoJet^® Sand. Resin composite cylinders were bonded onto the amalgam surfaces using Xeno^® IV, Optibond? All-In-One, Clearfil? SE Bond, Adper? Single Bond Plus, and Scotchbond? Multi-Purpose adhesive systems. In addition, silane (Monobond S) was used for Groups 5 and 6. The shear bond was determined and statistically analyzed using two-way analysis of variance and post hoc Tukey’s tests (p?≤?0.05). The surface treatment significantly affected the shear bond strengths of the adhesive systems. The shear bond strengths of Optibond? All-In-One (2.661?±?0.48?MPa) in Group 1 and Scotchbond Multi-Purpose (3.818?±?0.98) in Group 4 were significantly higher than those of the other adhesive systems. Silica coating of the amalgam surface significantly improved the shear bond strength of the resin composites. The addition of a retention hole on the amalgam affects the bonding strength of the composite adhesion.     

Effect of adhesive application on the shear bond strength of refrigerated and pre-heated of different composite resins to orthodontic molar tubes

Objective: To evaluate the effect of adhesive application on the shear bond strength (SBS) of orthodontic tubes to acid-etched human enamel using different temperatures and orthodontic composite resins. Methods: One hundred and twenty metal tubes were bonded to human third molars, which were randomly divided into three groups depending on the composite used: Transbond XT (XT); Transbond Supreme LV (LV); and Light Bond (LB). Each group was divided into four subgroups depending on the temperature (5°, 20°, 40°, and 60°) applied to the composite before cementing. For each experimental subgroup, half the specimens were bonded in combination with XT Primer. After 72?h, a SBS test was performed using a universal testing machine. Statistical analysis was performed using ANOVA, post hoc intergroup comparisons, chi-square test, and linear regression. Two representative molar surfaces from each subgroup were assessed under Scanning electron microscope. Results: The composite type only influenced XT regarding LB. The use of adhesive does not affect the SBS values of any composite. The flowable composites with adhesive containing zirconia (LV) as a filler showed lower SBS when cooled to 5?°C and when increases the temperature from 40?°C. Whether adhesive was used or not, composites with silica as filler (LB) showed lower SBS at 60?°C and increased to 5?°C. Conclusions: For all composites, from 20?°C, SBS values tend to increased and started to decline at 40°C except when adhesive is applied to the quartz-filled composite, which continues to increase, and the silica-filled composite without adhesive, which tend to decreases from 5?°C.     

The effect of recycled concrete aggregate properties on the bond strength between RCA concrete and steel reinforcement

The purpose of this study was to investigate the influence that replacing natural coarse aggregate with recycled concrete aggregate (RCA) has on concrete bond strength with reinforcing steel. Two sources of RCA were used along with one natural aggregate source. Numerous aggregate properties were measured for all aggregate sources. Two types of concrete mixture proportions were developed replacing 100% of the natural aggregate with RCA. The first type maintained the same water–cement ratios while the second type was designed to achieve the same compressive strengths. Beam-end specimens were tested to determine the relative bond strength of RCA and natural aggregate concrete. On average, natural aggregate concrete specimens had bond strengths that were 9 to 19% higher than the equivalent RCA specimens. Bond strength and the aggregate crushing value seemed to correlate well for all concrete types.     

The influence of stacking sequence on the strength of bonded CFRP single lap joints

The results of a limited experimental study are presented in which the effect of changing the stacking sequence in $\text{O}\text{±45°}$ lay-up carbon fibre-reinforced plastic adherends on the joint strength of bonded single lap joints was investigated. It is found that both lay-up and stacking sequence influence strength. Correlation between experiment and predictions from simple theory is fair for 8-ply laminates but no correlation is found for 6-ply laminates. The need for a more detailed theoretical model is indicated.     

The effect of functional monomer chain spacer length on the bond strength of an experimental dental adhesive

The study evaluated the effect of the carbon-chain spacer of monomers on the bonding effectiveness of two-step self-etching adhesive systems (SES). We investigated three acrylamidophosphonic acid monomers which vary only by the length of the carbon chain, 2-(N-methylmethacrylamido)ethylphosphonic acid, 6-(N-methylmethacrylamido)hexylphosphonic acid and 10-(N-methylmethacrylamido)decylphosphonic acid, on their effect in bonding performance while formulated in a self-etching primer with dentin and enamel. The results correlated well with those obtained from Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).It is concluded that there are no significant differences in terms of immediate Shear Bond Strength (SBS) on either enamel or dentin by using experimental self-etching primer (SEP) of different spacer chain length.     

Effect of adhesive application on the shear bond strength of flowable composite resins and APC plus to orthodontic molar tubes

Objectives: To evaluate the effect of adhesive application on the shear bond strength (SBS) of orthodontic tubes to acid-etched human enamel when using different flowable composite resins and the APC Plus system (APC). Study design: One hundred metal tubes were bonded to human third molars, which were randomly divided into five groups: Tetric EvoFlow (TF); Wave mv Flow (W); Transbond Supreme LV (S); Transbond XT (XT); and APC. For each experimental group, half of the specimens were bonded in combination with Transbond XT adhesive. After 72?h, an SBS test was performed using a universal testing machine. Two-way analysis of variance (ANOVA) was run for multiple comparison tests and for comparing the mean SBS among the 10 subgroups to evaluate the effect of both the composite and the adhesive factors. Then, a Student-Newman-Keuls test was used for pairwise comparisons using the highest mean SBS group as reference. Adhesive Remnant Index scores were determined for the teeth after failure and compared by χ ²-test. Two representative molar surfaces from the 10 subgroups were assessed under scanning electron microscope. Results: The application of adhesive did not have a significant effect, but there was a marked tendency toward the influence of the factor composite on SBS. The mean SBS of tubes bonded with XT with adhesive was significantly higher than that of those bonded with APC with adhesive, TF with and without adhesive, and S with adhesive. Conclusion: Flowable composites and the APC system without intermediate bonding resin could be conveniently applied for orthodontic tube bonding.     

Effect of fiber pretreatment condition on the interfacial strength and mechanical properties of wood fiber/PP composites

The effect of fiber surface pretreatment on the interfacial strength and mechanical properties of wood fiber/polypropylene (WF/PP) composites are investigated. The results demonstrate that fiber surface conditions significantly influence the fiber–matrix interfacial bond, which, in turn, determines the mechanical properties of the composites. The WF/PP composite containing fibers pretreated with an acid–silane aqueous solution exhibits the highest tensile properties among the materials studied. This observation is a direct result of the strong interfacial bond caused by the acid/water condition used in the fiber pretreatment. Evidence from coupling chemistry, rheological and electron microscopic studies support the above conclusion. When SEBS‐g‐MA copolymer is used, a synergistic toughening effect between the wood fiber and the copolymer is observed. The V‐notch Charpy impact strength of the WF/PP/SEBS‐g‐MA composite is substantially higher than that of the WF/PP composite. The synergistic toughening mechanisms are discussed with respect to the interfacial bond strength, fiber‐matrix debonding, and matrix plastic deformation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1000–1010, 2000     

The relationship between substrate roughness parameters and bond strength of ultra high-performance fiber concrete

The bonding that exists between the old concrete and the new concrete depends largely on the quality of substrate surface preparation. The accurate representation of substrate surface roughness can help determine very precisely the correct bonding behavior. In this work, an experimental investigation was carried out to quantify the normal concrete (NC) substrate roughness parameters and evaluate their relationship with the bonding performance of ultra high-performance fiber concrete (UHPFC), used as a repair material. The bond strength was quantified based on the results of the pull-off test, splitting cylinder tensile test, and the slant shear test. Three types of NC substrate surface preparation were used: as-cast (without surface preparation) as reference, wire-brushed, and sand-blasted (SB); the roughness of which was determined using an optical three-dimensional (3D) surface metrology device (Alicona Infinite Focus). It was observed from the result of the pull-off test that failure occurred in the substrate, even though adequate substrate surface roughness was provided. Moreover, analysis of the splitting cylinder tensile and slant shear test results showed that the substrate surface preparation method had a significant influence in bonding strength between UHPFC and the NC substrate. The composite UHPFC/NC substrate having a SB surface behaved closely as a monolithic structure under splitting and slant shear tests. An excellent correlation (R ²?>?85%) was obtained between the substrate roughness parameters and the results of the splitting cylinder tensile and slant shear tests.     

Modification of a nitrile-phenolic bonding agent by addition of an interfacial agent: effect on the practical adhesion between nitrile rubber and metal

—The mechanism of vulcanization bonding of a nitrile rubber (NBR) elastomer to metal with a single-coat nitrile-phenolic bonding agent is discussed. A nitrile-phenolic bonding agent consisting of NBR, phenol formaldehyde (PF) resin, and vulcanizing agents was modified with an interfacial agent (p-cresol formaldehyde resin) and the effect of interfacial agent addition on the practical adhesion between metal and the NBR elastomer after vulcanization was investigated. The adhesion strength was measured in terms of the metal-to-NBR elastomer peel strength using the bonding agent. The addition of p-cresol formaldehyde (PCF) resin to the bonding agent with a proportionate reduction of PF resin initially improved the peel strength; a maximum was reached at about 20% PCF content and then decreased with a further increase in the PCF content. The improvement in peel strength produced by the addition of PCF resin is attributed to the increased chemical bonding between NBR and the phenolic resin. The drop in peel strength above 20% PCF content is explained by the increased diffusion of the bonding agent into the NBR elastomer, away from the bond line, leading to a starved glue line. The mechanism for the optimum performance at about 20% PCF resin content is believed to be due to the balance of diffusion and chemical crosslinking.     

Modelling the elementary mechanisms involved in grafting polymers onto metals — relationship between structure and properties of the resulting product

With the aim of modelling the molecular-level phenomena involved in the interaction between a polymerizable organic molecule (acrylonitrile) and a controlled metallic surface (polycrystalline nickel), systematic experimental investigations and theoretical calculations have been carried out on polyacrylonitrile films grafted on nickel surfaces. Is is anticipated that the results, which indicate the relationships between structure, and properties and their evolution during ageing under various stresses, will enable the laws governing the behaviour of adhesive materials to be determined.     

纳米颗粒对环氧树脂胶粘剂／钢铁附着强度的影响

采用纳米Al2O3、纳米CaCO3、纳米SiO2三种纳米颗粒,机械混合对环氧树脂胶粘剂进行改性,并对纳米颗粒改性的环氧树脂胶粘试样进行了附着强度的检测。结果发现,通过改变纳米颗粒的种类和含量,环氧胶粘剂／钢铁基体之间的附着强度得到不同程度的提高,其中添加2％纳米Al2O3颗粒的环氧胶粘剂与钢铁基体的附着强度提高了4倍左右。通过断面形貌特征和不同基体粗糙度下对添加纳米颗粒环氧胶与钢铁基体之间附着强度的检测,对此现象产生的原因进行了分析和讨论。     

Correlation among crystalline morphology of PEEK,interface bond strength,and in‐plane mechanical properties of carbon/PEEK composites

The effect of the cooling rate on in‐plane and interlaminar properties of carbon fiber/semicrystalline PEEK matrix composites was studied. Strengths and moduli were measured in tension, flexure, and interlaminar shear, all of which were shown to correlate, to different degrees, with the fiber–matrix interface adhesion and the bulk matrix properties. The in‐plane and interlaminar properties, in general, increased with a decreasing cooling rate, which was attributed to changes in the failure mechanism from adhesive failure involving fiber–matrix interface debonding at high cooling rates to matrix‐dominant cohesive failure at low cooling rates. The present study demonstrates that the mechanical properties of semicrystalline thermoplastic composites can be tailored for desired applications by controlling the processing conditions, especially the cooling rate. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1155–1167, 2002; DOI 10.1002/app.10406     

The effects of maleic anhydride terpolymer and its ester derivatives on tensile bond strength between the acrylic resin and resilient lining material

The present study investigated the effects on the bonding between the denture base acrylic resin and the soft silicon based lining material of maleic anhydride‐styrene‐vinyl acetate (MA‐St‐VA) terpolymer and some of its ester derivatives. These ester derivatives were n‐propylmaleate‐styrene‐vinyl acetate (n‐PrMA‐St‐VA), n‐buthylmaleate‐styrene‐vinyl acetate (n‐BuMA‐St‐VA) and n‐benzylmaleate‐styrene‐vinyl acetate (n‐BzMA‐St‐VA). Fourier Transform infrared spectroscopy method was used to determine interactions between terpolymers with the acrylic resin and soft lining material. The tensile bond strength of all the groups was compared and the obtained differences were statistically significant (P < 0.05). The highest value was found for the samples lined with n‐BuMA‐St‐VA (2.11 ± 0.21 MPa) and the samples lined with n‐BzMA‐St‐VA had the lowest bond strength (0.3 ± 0.12 MPa). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1338–1341, 2007