Tensile Shear Bond Strength Research Articles

Influence of surface modification on thermal, adhesive properties and impact behavior of TPU films for laminated glass

Abstract The poor adhesion of TPU films limits their extensive application in lightweight laminated glass (LLG). A simple and effective method is reported in this paper to obtain modified TPU films by silane coupling agent (SCA) treatment. The polar groups (such as urethane groups, carboxyl groups, etc.) on the surface of TPU films reacted chemically with the reactive groups of SCA. Meanwhile, hydrogen bonds were formed between the silicon hydroxyl groups generated by the hydrolysis of SCA. Therefore, the adhesivity and thermal stability of TPU films were improved. Moreover, the surface of TPU films became rough after modification, hence the interfacial bonding area between TPU film and glass increased, which furthered the bonding effect of TPU film with glass plate. Compared with unmodified TPU films, the tensile shear bond strength (TSBS) of modified TPU films increased by nearly 28%, and the initial decomposition temperature increased from 277 °C to a maximum of 295.3 °C. The impact resistance of LLG was significantly improved due to the improvement of the adhesivity of TPU film.

Study on the Effect of Bond Strength on the Failure Mode of Coarse-Grained Sandstone in Weakly Cemented Stratum

Bond strength is one of the most important parameters and can affect the macroscopic mechanical properties and the damage state of rock to some degree. Coarse-grained sandstone was studied using the controlled variable method. The influence of parallel bond strength on the peak strength and failure mode of coarse-grained sandstone was simulated, and the evolution law of peak strength and the failure mode of bond strength were comprehensively analyzed. The results show that the peak strength of the rock was positively correlated with the bond strength; the difference in quantity between the tensile and shear cracks was negatively correlated with tensile bond strength and positively correlated with shear bond strength. With a tensile-shear bond strength ratio of less than 0.5, the peak strength of the rock was usually stable at the certain extreme value under a constant tensile bond strength. The tensile cracks were negatively correlated with the tensile-shear bond strength ratio, and the shear cracks were positively correlated with the tensile-shear bond strength ratio. The main failure mode of the coarse-grained sandstone in the weakly cemented stratum of the Hongqinghe coal mine is shear failure. The research results can be used to guide the ground control of other mine stopes or roadways with weak cementation lithology.

Single‐phase photo‐cross‐linkable adhesive synthesized from methacrylic acid‐grafted 1‐decene/9‐decene‐1‐ol cooligomer

AbstractThe cooligomerization of 1‐decene with 9‐decene‐1‐ol was conducted by using a Ti amine bis‐phenolate catalyst. Light‐curable adhesive was prepared by the reaction of methacryloyl chloride with the hydroxyl groups of the synthesized cooligomer, which led to the introduction of photo‐polymerizable CC double bonds into the cooligomer chains. Comonomer insertion into 1‐decene oligomeic chains and also methacryloyl chloride reaction with cooligomer were confirmed by both FT‐IR and NMR spectroscopy. Three‐point bending analysis results of cured adhesive sample (cured with blue light) showed flexural modulus and flexural strength values of 1.41 GPa and 1.66 MPa, respectively. Maximum weight loss temperature of 444°C showed high thermal stability of cured adhesive sample. In order to explore adhesion abilities of the synthesized adhesive to different substrates including polymethylmethacrylate (PMMA), polycarbonate (PC), polystyrene (PS), nylon and aluminum (Al), tensile shear bond strength, and peeling tests were conducted. Synthesized adhesive demonstrated tensile shear strength values of 1.28, 1.95, 1.10, 2.15, and 2.42 N/mm2 for PMMA, PC, PS, nylon, and Al substrates, respectively. Furthermore, obtained adhesive indicated greater tendency to polar substrates in comparison to nonpolar ones by the factor of 16–95%. Obtained results suggested a new photo‐curable adhesive with privileged features, which has capability to be used in high temperature applications.

Synthesis and characterization of one-component, moisture curing polyurethane adhesive based on Rokopol D2002

One-part, moisture curing polyurethane (PUR) adhesives based on poly(oxypropylene)diol Rokopol® and 4,4’-diphenylmethylene diisocyanate (MDI) modified with di-isononyl phthalate and a number of inorganic fillers and additives such as carbon black, thixotropic agent, dispersants and dibutyltin dilaurate as curing catalyst were developed. Adhesive curing was followed using dynamic oscillation rheometry and effect of some components on viscoelastic properties of curing materials was discussed. The cured materials were characterized by means of differential scanning calorimetry (DSC) and water contact angle measurements. The adhesive performance of obtained materials in bonding aluminum was evaluated by tensile shear bond strength tests.

Effect of temperature during vital gluten adhesive preparation and application on shear-bond strength

If protein-based adhesives are to become a competitive bio-based alternative to synthetic adhesives, the preparation and application methods have to be considerable improved to reduce process time and thereby improve the economy of the adhesive system. The purpose of this study was to investigate the impact of the temperature during preparation and application on the shear-bond strength of an adhesive based on vital gluten for use in wood applications. Vital gluten was used in its natural form and mixed with water of different temperatures (preparation temperature 0 °C or 20 °C), and applied on beech veneer at different temperature (application temperature –10, 20, 60 and 100 °C). Tensile shear-bond strength samples were prepared and tested according to EN 205. The results showed that an increase in veneer temperature during application of the adhesive led to a decrease in the shear-bond strength, but that the preparation temperature of the adhesive had no influence on the strength.

XPS depth profile of plasma-activated surface of beech wood (Fagus sylvatica) and its impact on polyvinyl acetate tensile shear bond strength

High surface selectivity of atmospheric pressure plasma treatment was demonstrated experimentally by XPS depth profile measurement of plasma-activated beech wood. Wood surface activated by diffuse coplanar surface barrier discharge was sequentially sputtered by Ar+ ion beam followed by immediate XPS analysis of freshly uncovered surface. According to the assessment, less than 330 nm of sputtered material was sufficient for complete removal of all plasma-formed functional groups. For the sake of practical implications of minimal vertical extent of plasma-mediated changes, the character of tensile shear bond strength improvement of polyvinyl acetate adhesive was examined with respect to its specific mass. A constant additive character of plasma activation to the bond strength was observed within the examined range of adhesive-specific mass.

Pengaruh bahan bonding self-etch terhadap kekuatan perlekatan antara pasak glass fiber dengan resin komposit

Nowadays, glass fiber post and composite resin cores have been used in endodontic treatment for esthetics achievement. The success of this treatment was affected by some factors such as bond strength between post and cores. The aim of this study is to investigate the effect of self etch bonding agent that use as adhesive materials between glass fiber post and resin composite by its bond strength. Totally twenty samples is used in this study, and divided in two groups (n=10 for each group), bonding group agents and without bonding agent group (control). The tensile-shear bond strength tested with Universal Testing Machine. Then, the bond strength values were analyzed statistically with t-test (p≤ 0,05). The result shows that bonds strength values in bonding agent groups were higher than without bonding agent groups. But, there is no significantly different between groups. In conclusion, bonding agent did not have effect on tensile-shear bond strength between glass fiber post and resin composite.

Influence of the degree of condensation of urea-formaldehyde adhesives on the tangential penetration into beech and fir and on the shear strength of the adhesive joints

The objective of this work was to evaluate the influence of the degree of condensation of urea formaldehyde (UF) resins on the tangential penetration into fir and beech and on the tensile shear bond strength of wood joints.

Effects of plasma treatment on the shear bond strength between fiber-reinforced composite posts and resin composite for core build-up

The aim of this study was to evaluate the effects of plasma treatment on adhesion between fiber-reinforced posts and a composite core material. Two types of posts, methacrylate-based (FRC Postec) and epoxy resin-based (DT Light-Post), were treated with oxygen plasma (O(2)), argon plasma (Ar), nitrogen plasma (N(2)), or helium mixed with nitrogen plasma (He+N(2)) using a radio-frequency generator before bonding to a methacrylate-based composite. Pull-out tests were performed using a universal testing machine. Surface roughness of each group was evaluated using a profilometer. On tensile-shear bond strength, statistical analysis revealed that the type of post, type of plasma treatment, and their interaction significantly influenced the results (p<0.05). Tukey's test revealed significant differences in tensile-shear bond strength between the control and other plasma treatment groups (p<0.05). On surface roughness, Tukey's test revealed significant differences between the control group and the Ar group (p<0.05) with DT Light Post. Plasma treatment appeared to increase the tensile-shear bond strength between post and composite.

Comparative Ex-Vivo Evaluation of the Frictional and Debonding Characteristics of Composite (Metal Inserted Plastic) Brackets.

The quest for increased esthetic demands in clinical orthodontic practice has lead to the development of tooth colored attachments like ceramic and polycarbonate bracket systems. First generation brackets of both these systems suffered a lot of shortcomings, which were rectified in successive generations. One such advancement is development of composite brackets and the present study is aimed at to compare 0.56 X 0.71 mm (0.022 X 0.028 inches) slot size, composite brackets - Classic‘ (Gold inserted), Elation‘ (Stainless steel inserted) and Spirit MB‘ (Stainless steel inserted) for the following parameters � (1) Frictional characteristics using 0.43 X 0.64 mm (0.017 x 0.025 inches) Stainless steel & Nitanium TM arch wires; (2) Tensile shear bond strength using Rely-a-bond! as bonding adhesive and (3) Surface characteristics. Conventional stainless steel bracketsGemini! was used as a control group. An instron universal testing machine was used to evaluate frictional characteristics and tensile shear bond strength. Stereo photomicroscope was used, to evaluate the extension and relation of the metal inserts to their respective slots, from the proximal and facial aspects of the brackets. Scanning electron microscope was used, for the surface characteristics evaluation of bracket slots before and after sliding the wires through slot. The results clearly indicated

Synthesis of novel moisture‐curable polyurethanes end‐capped with alkoxysilane and use as solvent‐free elastic adhesives

AbstractNovel silane endcappers and novel polyurethanes end‐capped with alkoxysilane (silylated polyurethanes) were developed as moisture‐curable materials, in which curing reaction occurs under humid conditions in the presence of dioctyltin diversatate as a curing catalyst. Two secondary amine‐terminated alkoxysilane compounds (silane endcappers) were synthesized by Michael addition reaction of commercially available N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane (or N‐(2‐aminoethyl)‐3‐aminopropylmthyldimethoxysilane) with methyl acrylate. The resulting silane endcappers were utilized to end‐capped isocyanate‐terminated polyurethanes, providing the silylated polyurethanes. The physical properties of the moisture‐curable silylated polyurethanes derived from several polyols and the silane endcappers were evaluated in terms of 50% modulus, tensile strength at break, elongation at break, and Shore A hardness after curing. The longer main chain of the silylated polyurethanes led to the lower Shore A hardness, the lower 50% modulus, and the longer elongation at break. In contrast, the tensile strengths at break were almost the same for all silylated polyurethanes, irrespective of the length of the main chain and the structure of the terminal silyl group. The silylated polyurethanes were employed for the preparation of novel solvent‐free moisture‐curable elastic adhesives, which were evaluated at the tensile shear bond strength. No significant influence of the molecular weight of the polyols and silane endcappers was observed on the tensile shear bond strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Synthesis of novel moisture‐curable polyurethanes end‐capped with trialkoxysilane and their application to one‐component adhesives

AbstractNovel silane endcappers and novel polyurethanes end‐capped with trimethoxysilane (silylated polyurethanes) were developed as water‐curable materials in which the curing reaction occurred under humid conditions in the presence of dioctyltin diversatate as a curing catalyst. A variety of amine‐terminated trimethoxysilane compounds were synthesized by the Michael addition reaction of commercially available 3‐aminopropyltrimethoxysilane with acrylates, and the resulting silane endcappers were used to react with isocyanate‐terminated polyurethanes, providing the silylated polyurethanes. The moisture‐curable silylated polyurethanes were used for the preparation of novel one‐component and solvent‐free adhesives. The evaluated properties were the curing speed, the tensile shear bond strength, and the adherence to some substrates. The longer alkyl chains of the silane endcappers derived from various acrylates led to a slower curing speed, lower tensile strength at break, and longer elongation at break of the silylated polyurethanes. The tensile shear bond strength of the silylated polyurethane‐based adhesive decreased with decreasing the trimethoxysilane end‐capping ratio, whereas an increase in the adherence was observed. The adherence to the acrylic substrate was improved by changes in the main‐chain structure of the polyurethane based on the composition of poly(propylene oxide) and poly(ethylene oxide). © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2689–2704, 2007

Effect of adhesive layer thickness on the bond strength of a zinc polycarboxylate dental cement

This study reports the effect of varying the thickness of a commercial zinc polycarboxylate dental cement on its adhesion in a metal-to-metal single lap joint. The thickness was controlled externally in a specially designed apparatus, rather than by the inclusion of isodimensional glass spheres, as has been done previously. The results show that both the tensile shear bond strength and the mode of failure of the cement are influenced by the thickness of the cement layer in the bonded joints. Hence, these results confirm previous findings that there is an optimum thickness for the zinc polycarboxylate layer. They also show that failure is more likely to be cohesive with thicker layers. The optimum thickness of the adhesive layer was 205 μm for the particular cement studied, PolyF Plus (De Trey, Dentsply, Weybridge, Surrey, UK), for which the average shear bond strength was found to be 4.03 MPa. Using stress analysis, the maximum shear and tensile stresses, τ 12(max) and σ 11(max), have also been obtained. These analyses showed that joints failed at the interface between the cement layers and the lap joint at adhesive layer thicknesses of below 100 μm. This resulted from the high stress concentrations in bonded joints with thin adhesive layers. On the other hand, thicker joints failed cohesively within the adhesive layer because of greater contributions from tensile stresses in these joints.

Tensile-Shear Bond Strength and Failure Between Aggregate and Mortar

Abstract The purpose of this study was to investigate the tensile-shear bond strength and failure of the mortar-aggregate interface. The techniques used are reported. The results indicate that the Mohr failure envelope in the tension-shear quadrant is almost a straight line and that the failure is essentially tensile in nature.