Strength Of Glue Research Articles

Determining Interface Strength of Glass-Metal Bi-Layer Laminates Using Cross-Push Method

Bond strength of metal-glass bilayer laminate was determined via a simple testing approach using cross-bonded sample and a special fixture. Tensile and shear strength in the interface for glass-metal composite were obtained by this way. It is demonstrated that the strength can be accurately determined when it is lower than the glue strength but it is invalid if the strength is higher than the glue strength. The specimen preparation and testing principle is introduced for determining the interface bonding strength of coatings.

Autologous glue: Part of the sticky mystery unraveled

The aim of the study was to evaluate the safety and efficacy of an autologous surgical tissue adhesive. Autologous glue was made out of canine concentrated plasma proteins mixed with 7.5% glutaraldehyde. Tensile strength and cytotoxicity of the autologous glue were tested. In a dog model, 8 transectioned iliac arteries were reanastomosed by using the animal's glue as the sole fixation method. After 120 days, all animals were angiographically controlled for patency and killed for histologic and immunohistochemical examination of the anastomosis. The autologous glue showed sufficient tensile strength (557 +/- 135 N/mm2). The elasticity of the glue is influenced by variations of concentrations in both proteins and glutaraldehyde. Glutaraldehyde remained cytotoxic, even at low concentrations of 2.5%. All operative procedures were successful. Angiographs performed before animal death showed all but 1 vessel to be patent and showed manifest compression signs in 3 anastomoses. Histological examination revealed only a foreign-body reaction adjacent to the surface of the glue. The autologous glue does not trigger any immune response on immunochemistry. Because fibroblastic neo-endothelial lining was near to normal, potential glutaraldehyde leaching does not seem too harmful for the vascular juncture in the dog model. Autologous glutaraldehyde glue has been used successfully as a vascular adhesive. In contrast to our previous studies with heterologous glue, we did not find a fierce acute inflammatory reaction indicating immune triggering. Nevertheless, glutaraldehyde remains a cytotoxic cross-linker. It is yet not known whether autologous glutaraldehyde glue can be used safely in clinical practice.

Surface modification of silicone sheets and tubes using plasma-based ion implantation

Silicone (polydimethylsiloxane) sheets and tubes were irradiated with Ar ions using plasma-based ion implantation (PBII). The roughness of the surface increased dramatically with increasing applied high voltage. The Raman spectra showed a destruction of methyl groups and the formation of amorphous carbon structures. The RBS measurements indicated an enrichment of carbon atoms and the presence of implanted ions at the surface. Owing to the irradiation, the adhesive strength of the fibrin glue (a biological tissue adhesive) improved from 0.08 to 0.57 N/mm 2 and the cell attachment percentage increased from 50 to 85% in a sample irradiated at 5 kV.

Development of A Novel Glue Consisting of Naturally-Derived Biomolecules: Citric Acid and Human Serum Albumin

A novel glue consisting of human serum albumin (HSA) and citric acid derivative (CAD) was developed where the glue is named as CAD-A glue. In this adhesive, CAD works as a crosslinking reagent of HSA. For preparing crosslinking reagent CAD, using citric acid as a starting material, three carboxyl groups of a citric acid were modified with N-hydroxysuccinimide in the presence of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride. From 1H-NMR spectrum, CAD with three active ester groups in a molecule was successfully synthesized with a high yield (more than 80%). The boding time of CAD-A glue to collagen-based casing was saturated within 15 minutes. The bonding strength of this glue to collagen-based casings increased with increasing of HSA concentration. The maximum bonding strength of CAD-A glue was a slightly low level compared to the bonding strength of cyanoacrylate adhesive and was 9 times higher than that of fibrin glue. The CAD-A glue showed excellent biocompatibility and high ability of wound closure similar to that of cyanoacrylate-based adhesive when glues were applied to the mouse skin. These results suggested that this developed adhesive had both tissue compatibility and bonding strength for use in clinical field.

Development of Biocompatible Glues for Minimum Invasive Therapy

A biocompatible glue consisting of human serum albumin (HSA) and citric acid derivative (CAD), named CAD-A glue was developed. CAD was successfully synthesized by the reaction between citric acid and N-hydroxysuccinimide in the presence of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride. When the CAD-A glue was applied to the collagenbased casings, it took 7 min to obtain half of maximum bonding strength (760 g/cm2). The bonding strength of this glue to collagen-based casings increased with increasing of HSA concentration.The bonding strength of CAD-A glue increased with increasing CAD concentration up to 200 mM, and then decreased with increasing CAD concentration under the fixed HSA concentration (50 w/w%). The CAD-A glue showed excellent wound closure ability rather than fibrin glue when applied to the mouse skin. These results suggested that this developed glue had both tissue compatibility and bonding strength for use in clinical field.

Measurement of Adhesion Strength of DLC Film Prepared by Utilizing Plasma-Based Ion Implantation

High-adhesion diamond-like carbon (DLC) film was prepared by a hybrid process of plasma-based ion implantation and deposition using superimposed RF and high-voltage pulses. The adhesion strength of DLC film on a stainless steel (SUS304) was enhanced by the carbon ion implantation to the substrate. Furthermore, ion implantation of mixed carbon and silicon led to considerable enhancement of adhesion strength above the resin glue strength. The adhesion strength of DLC film on the aluminum alloy (A-5052) was improved above the resin glue strength only by the carbon ion implantation to the substrate.

Characterization of a Protein-based Adhesive Elastomer Secreted by the Australian Frog Notaden bennetti

When provoked, Notaden bennetti frogs secrete an exudate which rapidly forms a tacky elastic solid ("frog glue"). This protein-based material acts as a promiscuous pressure-sensitive adhesive that functions even in wet conditions. We conducted macroscopic tests in air to assess the tensile strength of moist glue (up to 78 +/- 8 kPa) and the shear strength of dry glue (1.7 +/- 0.3 MPa). We also performed nanomechanical measurements in water to determine the adhesion (1.9-7.2 nN or greater), resilience (43-56%), and elastic modulus (170-1035 kPa) of solid glue collected in different ways. Dry glue contains little carbohydrate and consists mainly of protein. The protein complement is rich in Gly (15.8 mol %), Pro (8.8 mol %), and Glu/Gln (14.1 mol %); it also contains some 4-hydroxyproline (4.6 mol %) but no 5-hydroxylysine or 3,4-dihydroxyphenylalanine (L-Dopa). Denaturing gel electrophoresis of the glue reveals a characteristic pattern of proteins spanning 13-400 kDa. The largest protein (Nb-1R, apparent molecular mass 350-500 kDa) is also the most abundant, and this protein appears to be the key structural component. The solid glue can be dissolved in dilute acids; raising the ionic strength causes the glue components to self-assemble spontaneously into a solid which resembles the starting material. We describe scattering studies on dissolved and solid glue and provide microscopy images of glue surfaces and sections, revealing a porous interior that is consistent with the high water content (85-90 wt %) of moist glue. In addition to compositional similarities with other biological adhesives and well-known elastomeric proteins, the circular dichroism spectrum of dissolved glue is almost identical to that for soluble elastin and electron and scanning probe microscopy images invite comparison with silk fibroins. Covalent cross-linking does not seem to be necessary for the glue to set.

Complexities for Generalized Models of Self-Assembly

In this paper, we study the complexity of self-assembly under models that are natural generalizations of the tile self-assembly model. In particular, we extend Rothemund and Winfree's study of the tile complexity of tile self-assembly [Proceedings of the 32nd Annual ACM Symposium on Theory of Computing, Portland, OR, 2000, pp. 459--468]. They provided a lower bound of $\Omega(\frac{\log N}{\log\log N})$ on the tile complexity of assembling an $N\times N$ square for almost all N. Adleman et al. [Proceedings of the 33rd Annual ACM Symposium on Theory of Computing, Heraklion, Greece, 2001, pp. 740--748] gave a construction which achieves this bound. We consider whether the tile complexity for self-assembly can be reduced through several natural generalizations of the model. One of our results is a tile set of size $O(\sqrt{\log N})$ which assembles an $N\times N$ square in a model which allows flexible glue strength between nonequal glues. This result is matched for almost all N by a lower bound dictated by Kolmogorov complexity. For three other generalizations, we show that the $\Omega(\frac{\log N}{\log\log N})$ lower bound applies to $N\times N$ squares. At the same time, we demonstrate that there are some other shapes for which these generalizations allow reduced tile sets. Specifically, for thin rectangles with length N and width k, we provide a tighter lower bound of $\Omega(\frac{N^{1/k}}{k})$ for the standard model, yet we also give a construction which achieves $O(\frac{\log N}{\log\log N})$ complexity in a model in which the temperature of the tile system is adjusted during assembly. We also investigate the problem of verifying whether a given tile system uniquely assembles into a given shape; we show that this problem is NP-hard for three of the generalized models.

Investigation of the mix ratio design of lightweight aggregate concrete

According to the analysis of the domestic and overseas researches and achievements of lightweight aggregate concrete, a new strength formula on account of tube compressive strength of lightweight aggregate and glue–capacity ratio is put forward on the mix ratio design of lightweight aggregate concrete. The conception of concrete filler coefficient is also proposed, the theoretical formula of sand–aggregate ratio is deduced and the quasi-principle of stationary water consumption by considering the working character of concrete is summarized. Therefore, the designing equation of mix ratio of lightweight aggregate concrete which is tested by some further experiments is defined.

Thermal properties and adhesion strength of modified soybean storage proteins

AbstractSoy proteins have shown great potential for adhesive and resin applications. This investigation characterized the thermal and adhesive properties of the major soy protein components conglycinin (7S) and glycinin (11S) after chemical modification. These globulins were extracted from defatted soy flour, then modified with either sodium hydroxide, sodium dodecyl sulfate (SDS), or urea. Modified 7S, 11S, and mixtures of 7S and 11S at varying ratios were evaluated for gluing strength with cherry veneer plywood and for thermal denaturation using DSC. Adhesive strength and water resistance were significantly improved for all proteins modified with sodium hydroxide. Gluing strength and water resistance were improved for SDS‐ and ureamodified proteins containing greater portions of 7S globulins. The opposite behavior was observed for proteins containing large amounts of 11S globulins. DSC results showed that the temperatures of denaturation (Td) decreased for the proteins modified with sodium hydroxide or urea, whereas the Td values of proteins modified with SDS were similar to the unmodified proteins. These results suggested that, at the concentrations studied, sodium hydroxide or urea could denature soybean protein more effectively than SDS, resulting in lower protein thermal stability. Soybean proteins with high ratios of 11S had more ordered structures, as evidenced by the high enthalpy values of protein denaturation observed in DSC measurements.

In vivo use of human fibrin glue under the subperiosteal and subcutaneous planes in Holtzman rats

Background Commercial fibrin sealant has been increasingly used off-label in the United States for aesthetic surgical procedures to minimize postoperative drainage, hematoma and seroma collections, ecchymosis, and edema. Objective We sought to determine the optimal concentrations of thrombin and fibrinogen to extend the sealant adhesion time and to maintain the maximal glue strength, respectively, in subperiosteal and subcutaneous planes in Holtzman rats. Methods Three preparations of 2-component fibrin sealant from the Hemaseel APR kit (Haemacure Corp., Sarasota, FL) were formulated: standard fibrin sealant (fibrinogen 75-115 mg/mL, thrombin 500 IU/mL), half fibrinogen concentration (fibrinogen 37.5-57.5 mg/mL, thrombin 500 IU/mL), and 1/100 thrombin concentration (fibrinogen 75-115 mg/mL, thrombin 5 IU/mL). In 6 rats, paired standardized subperiosteal scalp pockets and subcutaneous abdominal pockets were elevated, leaving a retained septum between each pair. In experiment 1, 1 of the 3 fibrin sealant preparations was instilled into 1 side of each paired subperiosteal and subcutaneous pockets in 2 of the 6 rats, leaving the adjacent pocket as a control flap. Changes in force of flap displacement and in setup time for adherence within the treated and matched control flaps were measured at intervals over an hour. In experiment 2, the duration and strength of adherence in flaps treated only with the standard fibrin sealant preparation and their paired control flaps in 34 rats were measured weekly over 6 weeks. One of the 34 rats was sacrificed each week to examine the histologic changes at the tissue-glue interface. Results In flaps treated with the half-concentration of fibrinogen, the grams of force needed to displace the scalp flaps by 5 mm and the abdominal flaps by 10 mm were significantly reduced compared with values obtained in similar flaps treated with the standard fibrin preparation over 1 hour of interval measurements ( P < 0.05). In flaps treated with the 1/100 concentration of thrombin, the setup times before flap adherence were significantly extended to about 1 minute compared with the 15-second setup times observed in flaps treated with the standard fibrin preparation ( P < 0.05). The use of the standard fibrin preparation in 34 rats resulted in up to 6 weeks of tissue adherence in the subperiosteal scalp flaps and up to 2 weeks of tissue adherence in the subcutaneous abdominal flaps over the paired control flaps, as measured weekly on the basis of force of flap displacement. Histologic examination demonstrated that glue material was absent at about 5 to 6 weeks in the subperiosteal space and 2 to 3 weeks in the subcutaneous space. Conclusions Any decrease in fibrinogen concentration from that found in the standard fibrin sealant results in suboptimal strength of adherence of flaps. The standard thrombin concentration (500 IU/mL) results in a rapid onset of adherence within 15 seconds that may prevent the surgeon from massaging the glue evenly throughout the pocket and may produce a premature seal on opposing surfaces, leading to a seroma cavity. A reduced thrombin concentration (5 IU/mL), on the other hand, extends the onset time to a minute before adherence occurs, optimizing the sealing of the surgical cavity. (Aesthetic Surg J 2003;23:458-463).

Adhesive and morphological characteristics of surface chemically modified polytetrafluoroethylene films

In the present paper, we report an experimental determination of adhesive and topographic characteristics of chemically modified surface of polytetrafluoroethylene (PTFE) films. The surface chemistry was modified by ArF excimer laser irradiation in presence of triethylene-tetramine photoreagent. The applied laser fluence was varied in the range of 0.4–9 mJ/cm 2, and the number of laser pulses incident on the same area was 1500. To detect the changes in the adhesive features of the treated Teflon samples, we measured receding contact angle for distilled water and adhesion strength, respectively. It was found that the receding contact angle decreased from 96° to 30–37° and the adhesion strength of two-component epoxy glue to the treated sample surface increased from 0.03 to 9 MPa in the applied laser fluence range. Additionally, it was demonstrated that the adhesion of human cells to the modified Teflon samples is far better than to the untreated ones. The contact mode and pulsed force mode atomic force microscopic investigations of the treated samples demonstrated that the measured effective contact area of the irradiated films does not differ significantly from that of the original films, but the derived adhesion force is stronger on the modified samples than on the untreated ones. Hence, the increased adhesion of the treated Teflon films is caused by the higher surface energy.

Influence of glue rheology and joint thickness on the strength of bonded-in rods

The maximum pull-out strength of bonded-in rods was used for investigating the relationship between the joint geometry and the rheology of the structural adhesive. Tests with a brittle and a ductile glue type, both formulated with epoxy resins, showed that the glue rheology has a strong influence on the joint behaviour. The joint thickness is also an important parameter, having a good correlation with pull-out strength and with the fracture typology. Wood density and moisture content had a very low influence on strength, in these test conditions. A modification of the Eurocode 5 equation was developed, allowing an improved use of the adhesive properties for a safer design. Results suggest that a standardised test method for bonded-in rods would be very helpful for the determination of basic joint properties such as the maximum joint thickness and the glue strength parameter that were used in the modified design equation.

Development of new natural polymer-based wood adhesives I: dry bond strength and water resistance of konjac glucomannan, chitosan, and their composites

Bonding properties of konjac glucomannan (KGM), chitosan, and their composites were investigated. After preparing three-ply plywood glued with these materials, the dry bond strength and the bond strength after water immersion treatment were measured. The bond strength of urea-formaldehyde resin adhesive, casein, and soybean glues was also studied for comparison. KGM developed relatively good dry bond strength in extremely small solid amounts, irrespective of alkaline treatment. However, the water resistance was extremely low for all of the conditions. Chitosan also developed good dry bond strength in small solid amounts and was better than conventional adhesives. Chitosan also exhibited excellent water resistance compared to casein and soybean glues. When KGM and chitosan were combined, the adhesiveness under the dry condition was enhanced, and the bonding properties were superior to those of casein and soybean glues. Therefore, it is expected that chitosan and chitosan–KGM composite can be used as environmentally friendly wood adhesives.

A simple method for measuring tensile and shear bond strength of ceramic-ceramic and metal-ceramic joining

A simple method for measuring the ceramic-ceramic and metal-ceramic bond strength was presented, by which uniaxial tensile stress normal to the interface or shear stress in the interface can be produced using uniaxial compression load on a cross-bonded sample. Both tensile and shear bond strength were obtained by this testing technique for Ti3SiC2-TiO2 and Ti3SiC2-Al2O3 composite as well as for glued steel samples, respectively. The novel method provided a solution for determining bond strength in solid (especially brittle) materials, and it is also demonstrated as a useful method for evaluating the tensile and shear strength of various glues.

The mechanical properties of composites manufactured from tendon fibres and pearl glue (animal glue)

The mechanical properties of a composite manufactured from bovine tendon and pearl glue (an animal glue containing gelatine and other proteins) are investigated. This composite was traditionally used in the construction of Asiatic re-curve bows for archery and is reputed to be tough yet elastic. Composites were manufactured by hand laying fibres into a mould and then pouring on hot glue. Tensile tests were performed on the specimens with the load being applied along the long axis of the fibres. The composite was found to absorb 18 MJ/m3 of energy to failure, comparable to carbon fibre composites, spring steel and butyl rubber. This energy absorption was achieved through the ductility and strength of the collagen fibres, which were found to be several times larger than the glue (fibre strength was 180 MPa, glue strength was 32 MPa, fibre failure strain was 26%, glue failure strain was 3%). However, the tensile modulus of the fibres and glue were similar. The composite was also found to be extremely damage tolerant, with many micro-cracks developing between strains of 2–20%, and dominated by elastic behaviour to surprisingly large deformations. The reasons for this are discussed.

Adhesive strength of guanidine hydrochloride—modified soy protein for fiberboard application

Adhesive properties of guanidine hydrochloride (GuHCl)-modified soy protein isolate (SPI) for uses in fiberboard were investigated. In addition, effects of GuHCl concentration, SPI concentration, press conditions, and assembly time on gluing strength were studied. Shear strength changed with variation of GuHCl concentration and had a maximum value at 1.0 M GuHCl. Increasing the SPI content improved shear strength greatly at a low concentration, and increasing SPI to high concentrations had little additional effect. Overall shear strength decreased after water soaking, but showed same trends with GuHCl concentration and with SPI content as unsoaked samples. Shear strength increased as press temperature increased but leveled off at high temperature. Press temperature had a greater effect on the soaked samples. Both press time and assembly time had significant effects on shear strength. The maximum shear strength was obtained with a press time of 5 min and assembly times of 10–15 min, respectively. All samples prepared at 75°C or above exhibited cohesive failure within fiberboard. However, samples prepared at 25°C and 50°C showed both cohesive failures within fiberboard and locus of failure following the interface between the adhesive and adherend. Furthermore, some glued specimens fell apart after soaking.

Biological tissue adhesive for multiple use in the accident and emergency department

Objective—To assess the strength of the glue and microbial contamination over 28 days from opening a vial of tissue adhesive in the accident and emergency setting, and to quantify cost...

Soft tissue adhesive composed of modified gelatin and polysaccharides

Although fibrin glue has been clinically used as a surgical adhesive, hemostatic agent, and sealant, it has the risk of virus infection because its components, fibrinogen and thrombin, are obtained from human blood. To circumvent this problem, we employed bioabsorbable gelatin and polysaccharides to prepare a safer hemostatic glue. Gelatin was modified with ethylenediamine using water-soluble carbodiimide to introduce additional amino groups into the original gelatin, while dextran and hydroxyethyl-starch were oxidized by sodium periodate to convert 1,2-hydroxyl groups into dialdehyde groups. Upon mixing of the two polymer components in aqueous solution, Schiff base was formed between the amino groups in the modified gelatin and the aldehyde groups in the modified polysaccharides, which thus resulted in intermolecular cross-linking and gel formation. The fastest gel formation took place within 2 s, and its bonding strength to porcine skin was about 225 gfcm-2 when 20 wt% of an amino-gelatin (55% amino) and 10 wt% of aldehyde-HES (>84% dialdehyde) aqueous solutions were mixed. In contrast, the gelation time and bonding strength of fibrin glue was 5 s and 120 gfcm-2, respectively.

Adhesive Strength of Autologous Fibrin Glue.

To establish an easy and rapid method for measuring the adhesive strength of fibrin glue and to clarify the factor(s) most affecting the strength, a study was made on the effect of the concentration of plasma components on the strength of cryoprecipitate (Cryo) prepared from a subject's own autologous plasma to be used as fibrin glue. The adhesive strength of the Cryo was measured with various supporting materials instead of animal skin using a tester of tension and compression. The results were as follows: (1) the strength of Cryo applied to ground flat glass (4 cm2) was significantly greater than that applied to clear glass, clear plastic, or smooth and flat wood chips; (2) the adhesive strength of Cryo depended on the concentration of thrombin with the optimal concentration being 50 units/ml; (3) the concentration of CaCl2 did not affect the adhesive strength of Cryo; (4) the adhesive reaction was dependent on the temperature and the adhesive strength more quickly reached a steady state at 37 degrees C than at lower temperature; (5) the adhesive strength was correlated well with the total concentration of fibrinogen and fibronectin. These results indicate that the adhesive strength of Cryo can be easily and quickly evaluated using a tester and ground glass with thrombin at 50 units/ml, and that the adhesive strength of Cryo can be predicted from the total concentration of fibrinogen and fibronectin.