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Water-soluble pressure-sensitive adhesives (PSA) based on acrylic acid and carboxymethyl starch (CMS) have been prepared. The tack and peel adhesion to various paper types (newsprint, hygienic, packing, fax and art paper) as well as dynamic shear adhesion at higher temperatures (70-240 °C) have been tested with the aim of applying such PSA in a form of double-sided splicing tapes for paper industry. For all paper types tested tack and peel adhesion values increased with CMS content (0.1-10 wt% in PSA). The highest tack and peel adhesion values (for the system containing 10 wt% CMS) were noted for fax paper ca. 19.5 N/2.5 cm and 18.3 N/2.5 cm, respectively and the lowest ones for art paper: 14.7 N/2.5 cm and 13.5 N/2.5 cm, respectively. Obtained PSA were completely soluble in water, and the time of water-solubility depended on CMS content, as well as pH value, however it did not exceed 5 min. [ABSTRACT FROM AUTHOR]

Fiber agglomeration and poor interfacial combination with the matrix restrict the performance of composites. Herein, soybean meal-based adhesives were fabricated via the addition of dialdehyde cellulose (DAC) obtained from waste paper dissolved in an alkali–urea system and oxidized with sodium periodate. Due to the dissolution by the alkali–urea system, DAC dispersed well in the solution and did not aggregate in the adhesive matrix. Because of the oxidation treatment, DAC was crosslinked with the adhesive matrix via a Schiff base reaction. Meanwhile, hydrogen bonds were formed at the interface between the DAC and the adhesive matrix. Plywood with the SM/DAC/PTGE adhesive reached its highest wet bonding strength of 1.27 MPa (4 wt% DAC addition), a 95% increase compared to that with the unmodified SM/PTGE adhesive. Fine DAC-to-SM interfacial bonding and a dense crosslinking network were constructed in the SM/DAC/PTGE adhesive systems. The cycle of reuse for the alkali–urea system in the experiments demonstrated that the preparation method of the cellulose solution was scalable and sustainable. [ABSTRACT FROM AUTHOR]

Two types of Japanese papers containing 100 % (JP1) and 50 % (JP2) kozo fibers were treated with different adhesives: methyl-cellulose, rice starch, hydroxypropyl-cellulose and acrylic copolymer. The Fourier transform infrared spectroscopic (FTIR) analysis confirmed the formation of adhesive layer on the surface of papers. The influence of accelerated ageing procedures of moist heat ageing and UV radiation on sample surfaces was established using FTIR and contact angle measurements. The degradation level of papers was studied measuring the intrinsic viscosity and determining the degree of polymerization. Mechanical properties were determined by tensile tests. The results showed that the polar and dispersive components of the surface energy depend strongly on the surface treatments as well as on conditions of ageing. Analysis of degree of polymerization and tensile strength revealed that treatment with methyl-cellulose, rice starch and hydroxypropyl-cellulose reduced degradation of Japanese papers. [ABSTRACT FROM AUTHOR]

For the conservation of artworks on paper, powdery paint layers on the paper matrix are stabilized with dilute solutions of adhesives (0.25-1 %), commonly gelatin or methylcellulose, which are applied as aerosols. This technique allows non-contact application. The distribution of the adhesives must be carefully controlled: they have to be delivered to unstable paint layers in the right quantity to avoid visual alterations of the artwork during the stabilization treatment. To visualize the distribution of aerosol-misted adhesives in porous substrates, gelatin and methylcellulose were labeled with fluorescent dyes, purified from excess label, and applied on sample specimen featuring powdery pigment layers on handmade rag paper. As blank comparisons, sample papers without pigment layers were included to verify whether aerosol-misted adhesives are a suitable method to stabilize fragile papers. Penetration of the adhesive-label-conjugates was observed at thin sections of the samples by fluorescence microscopy. The fluorescence labeling of gelatin with Texas Red™ allowed an excellent visualization of aerosol-misted adhesive (0.5-1 %) in all sample types. Methylcellulose (Methocel™ A4C) labeled with Texas Red™ C2-dichlorotriazine enabled fluorescence tracing if applied in 0.5 % solutions by immersion. Aerosol application permitted local adhesive application, making it a suitable technique for stabilizing fragile papers. If applied to samples with low porosity, aerosol-misted gelatin was mainly deposited at the surface, whereas in porous filter paper, penetration dominated over surface deposition. Intermediate drying between repetitive applications apparently limited the penetration of aerosol-misted gelatin. [ABSTRACT FROM AUTHOR]

Jelly glue made of gelatin is frequently used in the packaging industry. The purpose of this study is to determine whether starch and polyvinyl alcohol (PVA), which were introduced at a 1.0% concentration, could be used to develop with improvement in the performance properties of jelly adhesives that are being prepared. By examining viscosities at different temperatures, pH, water contact angles, differential scanning calorimetry (DSC), tensile strength on wood and setting speed observation on coated paper, and performing pencil hardness tests on films, the effect of adding starch and PVA as a binder on physical, thermal, and mechanical properties were studied. When starch and PVA were added to the jelly glue, DSC data showed a substantial rise in the glass transition temperature, which were further confirmed by film hardness testing. The addition of starch increased the adhesive's viscosities at different temperatures. When compared to an original sample, the tensile strength with starch increased by ~ 74% after 24 h of bonding in a dry environment. The jelly adhesive with starch showed increased in water resistance which was also validated from contact angle test. Unlike PVA-based jelly glue, the hydrogen bonding in starch and gelatin showed superior mechanical properties. This research discusses starch as a potential substitute for the development of jelly adhesive. The technique developed offers an easy and useful path to adhesives with increased water resistance and bonding strength by using starch as a binder. Ecologically sound, sustainable, and economically acceptable were the methods used to increase jelly adhesive's resistance to moisture. The study's overall finding highlights the superior and sustainable adhesive performance of jelly glue based on starch as a packaging adhesive. [ABSTRACT FROM AUTHOR]

The searches were carried out independently by two authors, using the following research strategy U for MEDLINE/PubMed u : (((((((((((((((((Leakage[MeSH Terms]) OR restoration[MeSH Terms]) OR adhesives[MeSH Terms]) OR bonding[MeSH Terms]) OR bond[MeSH Terms]) OR caries[MeSH Terms]) OR secondary caries[MeSH Terms]) OR Leakage[Title/Abstract]) OR restoration[Title/Abstract]) OR adhesives[Title/Abstract]) OR bonding[Title/Abstract]) OR bond[Title/Abstract]) OR caries[Title/Abstract]) OR secondary caries[Title/Abstract])) AND ((((((cariostatic[MeSH Terms]) OR fluorides[MeSH Terms]) OR fluoride[MeSH Terms]) OR cariostatic[Title/ Abstract]) OR fluorides[Title/Abstract]) OR fluoride[Title/ Abstract])) AND ((((Remineralization[MeSH Terms]) OR demineralization[MeSH Terms]) OR Remineralization[Title/ Abstract]) OR demineralization[Title/Abstract])) AND ((((in-vitro[MeSH Terms]) OR in vitro[MeSH Terms]) OR in-vitro[Title/Abstract]) OR in vitro[Title/Abstract]). Evaluation of the efficiency of fluoride-releasing adhesives for preventing secondary caries in-vitro: a systematic review and meta-analysis. [Extracted from the article]

Reducing the amount of industrial crop waste and converting it into high value-added products in a sustainable manner will not only promote the use of biological resources but will also help in reducing the environmental impact. Bast fibers of Kozo (Broussonetia kazinoki) are a raw material of traditional Japanese paper, known as "Washi." However, the wood part of this plant is not used for Washi and is discarded. The aim of this study was to find a new future use for the wood parts of the plant. The first step was to confirm whether the wooden part of Kozo could be converted into cellulose nanofibers (CNFs). CNFs made from bast fiber alone and from bast fiber that included the outer bark were prepared as samples for comparison. Subsequently, the morphological and chemical structures of the raw materials, wood powder, pulp, and CNFs from each sample were analyzed. Consequently, we found that CNFs made from wooden parts have a chemical structure similar to that of the bast fiber, which is the raw material of Washi; however, it is the thinnest CNF of all those investigated. In addition, the CNF solution prepared from wooden parts adjusted to a 0.5-wt% concentration showed the highest viscosity characteristics and also the highest adhesive strength when applied to Japanese paper. These results indicate that waste wood parts have potential applications as chemical-free thickeners, adhesives, and restorative materials. [ABSTRACT FROM AUTHOR]

UV debonding acrylate pressure-sensitive adhesives (UPSAs) are necessarily applied in the semiconductor industry. To establish a comprehensively understood method is important to detect their bonding and debonding behaviors. In this paper, rheological methods, including Three Interval Thixotropy tests (3ITT) and Tack test modes were used for characterizing series of UPSAs. Vinyl groups were successfully grafted onto the acrylate copolymer chains through isocyanate condensation reactions, which were characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy and gel permeation chromatography. From the maximum normal force in the Tack test modes, UPSAs after UV irradiation showed obvious debonding behaviors in short-time stress analysis. The recovery percentage of the storage modulus in 3ITT tests indicated that 0.6 wt% isocyanate curing agent made the UPSAs good resistance to deformation. Under the limit of 30 wt% pentaerythritol diacrylate (PETA), the rheological adhesion performance of UPSAs increases accordingly with the PETA content, which was also confirmed by 180° peel strength tests. From the microscope images of the wafer surfaces after peeling off the UPSA tapes, rheological characterization methods can help designing UPSAs with clean debonding properties. [ABSTRACT FROM AUTHOR]

Damage and fracture of archaeological potteries not only jeopardize the long-term preservation but also hinder their exhibition. To repair these pottery sherds effectively, this study introduces a novel inorganic phosphate-based adhesive and evaluates its effectiveness through a series of experiments. To determine the optimal base adhesive, the paper investigates the influence of varying weight ratios of the H2O–H3PO4 system and the Al(OH)3–H3PO4 system on properties including tensile lap-shear strength, microstructure, high-temperature resistance and phase composition. However, the original black color of the traditional CuO–phosphate adhesive limits its application. The innovation of this study lies in the addition of nano-TiO2 to the adhesive, which not only improves the bonding strength but also adjusts the color of the adhesive. This study has defined the optimal formulation (i.e., base adhesive = m[Al(OH)3]:m[H3PO4] = 7:100, filler = 10wt% nano-TiO2), and the final product shows no residual acid in adhesives. Additionally, the fracture surfaces are successfully bonded with a high strength of 3.56 MPa. Various ageing tests including dry-thermal ageing, hygrothermal ageing and UV irradiation ageing are conducted to assess the ageing resistance of the inorganic phosphate-based adhesive. The results indicate strong tolerance of adhesive to high temperature and high humidity environment. Preliminary applications in archaeological pottery restoration suggest that the inorganic phosphate-based adhesive offers considerable promise for repairing shattered pottery. [ABSTRACT FROM AUTHOR]

The combined approach of classical fingerprinting and DNA profiling is a powerful tool in forensic investigations of latent "touch" traces. However, little attention has been paid to the organic solvents frequently used in dactyloscopic laboratories to facilitate the separation of adhesive evidence prior to fingerprint development and downstream effects on subsequent DNA profiling. In the present study, we tested a selection of adhesive removers (n = 9) and assessed their potential impact on DNA recovery and amplification by PCR. Thereby, we identified and characterized novel PCR inhibitors. All investigated chemicals contain volatile organic compounds that evaporate under normal indoor atmospheric conditions. Exposure to certain solvents resulted in increased DNA degradation, but only if evaporation was prevented. A series of adhesive-removal experiments were conducted with prepared mock evidence (self-adhesive postage stamps affixed to paper envelope) to investigate the impact of treatment time and the location of applied traces on DNA recovery and dactyloscopy, respectively. Due to the early onset of print decomposition, we found that only a short treatment time was compatible with the development of fingerprints on the adhesive side of a stamp. Solvents also removed DNA from the adhesive surface, thus resulting in a marked shift in the substrate distribution of recovered DNA from the stamp to the envelope, but not in the reverse direction. Furthermore, we observed that treatment with conventional fingerprint reagents lead to a significant reduction in the amounts of DNA recovered from stamps, while the additional use of adhesive removers did not significantly enhance this effect. [ABSTRACT FROM AUTHOR]

Researchers of the Nekrasov Iron & Steel Institute, National Academy of Sciences of Ukraine, conduct studies aimed at developing analytical methods for predicting the strength characteristics of pellets. These studies use analyses of phase interaction mechanisms within free-flowing media to develop theoretical ideas on the formation of strong bonds in the pellets through adhesion. This led to the establishment of local models of adhesion processes for two basic particle interaction schemes: 'particle + particle' and 'particle + liquid phase + particle'. Experimental studies undertaken in laboratory premises of the Nekrasov Iron & Steel Institute for the 'particle + particle' interaction scheme provided the foundation for a method to determine the strength characteristics of pellets made from fine-grained materials with zero moisture at compaction pressures ranging from 50 to 220 MPa. The first part of the paper justified methodological prerequisites for experiments to study strong bonds within the compacts for the 'particle + liquid phase + particle' interaction scheme. The methodological prerequisites accounted for the mechanical, physical, and physicochemical interactions, both between individual particles of the pelletized material and between the charge components (liquid phase). A generalized analysis of the experimental findings allowed evaluating a range of potential adhesion processes for the 'particle + liquid phase + particle' interaction scheme, pinpointing their manifestation, examining their nature, and assessing the effect of a liquid phase introduced into the pelletized charge, considering the compaction pressures applied. This paper focuses on experimental findings for the 'particle + liquid phase + particle' interaction scheme, establishing analytical relationships between the strength characteristics of pellets and integral indicators of the adhesive bond mechanism in this interaction scheme (in particular, relationship between the bulk density (ρ0) and moisture content (Wm) for materials in the first group of systematization). Additionally, an analytical relationship between the compaction factor for compacts produced at a pressure (P) of 220 MPa (Kcomp220), considering their loosening, and the bulk density of materials (ρ0) in the first group of systematization was established for the first time. Analysis of the findings led to a hypothesis suggesting that the amount of the liquid phase (in particular, water) introduced into the material should be balanced by its potential displacement during compaction to achieve maximum compact strength. Based on the hypothesis, a novel equation was derived to calculate the amount of liquid binder (water) to promote the most favorable conditions for the adhesion processes, thereby imparting the maximum strength to compacts from materials in the first group of systematization. A comparative analysis between the experimental findings and calculations confirmed that the equation was accurate. Consequently, an analytical method was proposed to determine the moisture content needed in the charge to produce compacts with maximum strength from materials in the first group of systematization (ρpycn ≥ 4.64 × × 10–3). [ABSTRACT FROM AUTHOR]

The article presents a list of papers published in the 2004 and 2005 issues of the "Journal of Materials Science." Some of the papers listed are: "Adhesively-Bonded Joints and Repairs in Metallic Alloys, Polymers and Composite Materials"; "Role of Entropy of Fusion in Phase Transformation and Self-Diffusion"; "Models in Thermoluminescence"; "Electrical Applications of Carbon Materials"; "Use of Polymers for Cement-Based Structural Materials"; and "Effect of Anions on the Textural and Catalytic Activity of Titania-Silica Mixed Oxide."

Tantalum is widely used in capacitor field in modern times. The tantalum shell of capacitor is usually obtained by deep drawing process, and adhesive wear of the shell is the main hidden danger during its deep drawing process. In this paper, ultrasonic vibration–assisted deep drawing technology is proposed to manufacture tantalum capacitor shell, in order to effectively control the adhesive wear of tantalum capacitor with the assistance of ultrasonic vibration energy. Influence of ultrasonic vibration on deep drawing force and surface forming accuracy of tantalum cup deep drawing is discussed by applying different amplitudes of ultrasonic vibration signals at different time periods. The results reveal that in the amplitude range of 3–7 μm, the amplitude of 5 μm has the best inhibition effect on adhesive wear during the deep drawing of tantalum cup, and the effect is especially obvious in the initial stage of the deep drawing process; the reduction of wearing can reach more than 22% comparing with the results without ultrasonic amplitude. [ABSTRACT FROM AUTHOR]

A list of articles related to physics is presented in the December 2005 issue of the "Journal of Materials Science" including "Adhesively-Bonded Joints and Repairs in Metallic Alloys, Polymers and Composite Materials," by A. Baldan, "Thermo-mechanical fatigue of shape memory alloys," by E. Hornbogen, "Role of Entropy of Fusion in Phase Transformation and Self-Diffusion," by G. P. Tiwari, J. M. Juneja and Y. Ijima, "Models in Thermoluminescence," by C. Furetta and G. Kitis and "Electrical Applications of Carbon Material," by D. D. L. Chung.

In the microdrilling of metal, an exit burr forms due to plastic deformation of the remnant material when the drill approaches the bottom of the hole. In this work, a cyanoacrylate adhesive was applied at the exit surface to prevent the exit burr. The copy papers smeared with cyanoacrylate were layered at the exit surface in a uniform coat. The cyanoacrylate can be easily removed by immersion in acetone. The cyanoacrylate layer was effective in preventing exit burr in the drilling of low-hardness materials, such as aluminum or copper. In the case of harder materials, however, such as 304 stainless steel, the cyanoacrylate layer failed. In this case, backup foil adhered with cyanoacrylate was shown to be effective in burr prevention. [ABSTRACT FROM AUTHOR]

The paper addresses the mathematical justification of a model describing steady vibrations for a planar thermoelastic body with an incorporated thin inclusion. The body is composed of three parts: two adherents and an adhesive layer between them, and we begin with a general mathematical formulation of a problem. By means of the modern methods of asymptotic analysis, we rigorously investigate the behavior of solutions as the thickness of the adhesive tends to zero. As a result, we construct the model that corresponds to the limit case. It turned out that the adhesive is reduced to the inclusion, which is thin (of zero thickness) and relatively hard (compared to the rigidity of the surrounding body). Furthermore, we supplement the obtained results with numerical experiments demonstrating the consistency of the theoretical conclusions. [ABSTRACT FROM AUTHOR]

The research reported here focuses on developing wood adhesive by mixing liquid glucose (LG) and polyvinyl alcohol (PVA) in water. Here, boric acid is used as a crosslinking agent to improve the LG–PVA blend's thermomechanical characteristics. The impact of crosslinking was measured using a variety of analytical techniques, including viscosity testing, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and water contact angle testing. By pouring LG–PVA blends onto Teflon sheets, a film was made. On performance parameters like tensile strength, pencil hardness, and thermal properties like glass transition temperature, the impacts of several variables, such as increasing the amount of LG and boric acid, were examined. In the water contact angle test, the crosslinked blend films showed decreased hydrophilic behavior and increased pencil hardness. The films glass transition temperature (Tg) was positively impacted by the higher BA concentration. For the crosslinking reaction with boric acid, the free hydroxyl groups present in LG and PVA serve as an active sites. Crosslinks between the hydroxyl groups of LG and PVA are expected to take place as a trivalent boron attracts these nucleus-loving groups. FTIR spectrum measurements confirmed the interaction of boric acid with the LG–PVA mixture. The reaction was accelerated by the acidic pH, and its effects were shown in the rise in thermomechanical properties. By lowering the free volumes between the chains, the crosslinking improved cohesion, and as a result, an increase in strength on glued wood specimens was observed. [ABSTRACT FROM AUTHOR]

Nowadays, with the increasing demands for quality and precision in microelectronic packaging, the study and prediction of droplet parameters before packaging have become increasingly important. This paper aims to derive a predictive formula for droplet volume dispensing to improve packaging quality, optimize process parameters, reduce resource waste, enhance process control, and enhance product quality and reliability. Based on the needle transfer method for ultra-microdroplet dispensing, a droplet dispensing device that meets packaging requirements is established, and precise control of droplet volume is achieved by changing the factors that affect droplet formation. The droplets obtained from experiments are analyzed using pixel extraction, and a numerical fitting method is employed to establish a droplet volume model. It is found that the pixel method is a practical approach for determining droplet volume, with an average deviation of approximately 1.85%. By conducting droplet dispensing experiments with varying initial distances, the smallest droplet volume achieved is 24.33 pL, and it is concluded that larger initial distances result in smaller droplet volumes and reduced droplet contact area. Based on the droplet dispensing experimental data obtained by varying the initial distance, mathematical predictive models for droplet volume and droplet contact area are derived. The results show that the average difference rate between predicted and actual volumes is 0.51%, and the average difference rate between predicted and actual contact areas is 0.56%. [ABSTRACT FROM AUTHOR]

In this paper, results are reported from a series of laboratory tests conducted on a swelling soil treated with different jute fibers with a twofold objective of reducing their swell characteristics and enhancing their geomechanical properties. The efficacy of passive inclusion of three different jute fibers (i.e., natural, woven, and bitumen coated) in controlling both swell potential and pressure, and improving undrained shear strength and consolidation behavior has been examined. It is observed that the inclusion of jute fibers in the swelling soil expectedly improves both undrained shear strength and CBR value of the treated soil. For instance, the original undrained shear strength improves from 200 kPa to as high as 675 kPa and the original CBR value increases from 3% to a maximum of 7.1%. Similarly, both swell potential and pressure of the treated soil reduced significantly from 4.1% to as low as 1.2% and from 90 kPa to a minimum of 40 kPa, respectively. The improvements in soil properties could be attributed to the reinforcing ability of fibers, which possess a relatively higher tensile strength, in corroboration with the adhesive bond between fibers and soil particles at the micro level. While the former plays an active role in avoiding progression of shear failure, the latter would passively resist the initiation of slip at the soil-fiber interface. Notably, while shear strength of soil generally improves upon addition of jute fibers, inclusion of the bitumen coated fibers has been observed to be more effective than rest. [ABSTRACT FROM AUTHOR]

The stress-strain state that occurs in multilayered structures (for example, beams) significantly depends on the nature of the interaction of their layers. In practice, when calculating such structural elements, an ideal contact of the layers is most often considered, this implies the continuity of displacement vectors and stresses at the contact boundary. Strict elasticity theory solutions in this case inevitably lead to the appearance of infinite tangential stresses on the free surfaces at the angular points of structures at the layer interfaces. In this paper, the problem of the stress-strain state of a multilayered beam is considered in which the interaction of layers is assumed nonideal. For this aim, a layer interaction model with a thin contact layer between the adhesive and adherends is chosen. The equations obtained on the basis of this model allowed us to find non-singular solutions that describe the essentially inhomogeneous stress-strain state in each layer of the beam and at their interfaces. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of the effect of vacuum ion–plasma treatment on the strength of the adhesive joint of the samples of fiberglass VPS-48/7781-14 grade. The results of the study of the contact angle of wetting the surface of fiberglass, the microstructure of the surface and the shear strength of the adhesive joint after ion–plasma treatment in various modes are presented. [ABSTRACT FROM AUTHOR]

This paper investigated the effect of cavity cleaning methods on the bond strength of adhesive systems to dentin after removing zinc-oxide eugenol (ZOE) temporary material. Coronal parts of 96 extracted third molar teeth were removed, and occlusal access cavities were prepared. After root canal treatment, cavities were filled with ZOE and stored in distilled water for seven days at 37°C. After ZOE was removed, teeth were randomly divided into three groups according to cavity cleaning methods (control, 2% chlorhexidine, and ethanol), and five subgroups (3-step total-etch, 2-step self-etch, 1-step self-etch, universal adhesive, and chlorhexidine containing universal adhesive). After restoration with composite resin, the specimens were sectioned into 1 mm2 surface area beams. A microtensile bond strength (μTBS) test was performed. Failure modes were determined under a stereomicroscope and analyzed with a scanning electron microscope. The highest μTBS was observed in chlorhexidine-containing universal adhesive after applying ethanol for 30 s. Ethanol application for 30 s created cleaner dentin surfaces and could increase the adhesive penetration by removing the ZOE residues better than the control and 2% chlorhexidine application for 30 s. [ABSTRACT FROM AUTHOR]

Grinding tools can be manufactured from metal, vitrified, and resin bond materials. In combination with superabrasives like diamond grains, metal-bonded tools are used in a wide range of applications. The main advantages of metal over vitrified and resin bonds are high grain retention forces and high thermal conductivity. This paper investigates the influence of the atmosphere and manufacturing parameters such as sintering temperature on the properties of titanium-bonded grinding layers. Titanium is an active bond material, which can increase the retention of diamond grains in metal-bonded grinding layers. This can lead to higher bond stress and, consequently, decreased wear of grinding tools in use when compared to other commonly used bond materials like bronze. The reason for this is the adhesive bond between titanium and diamond due to the formation of carbides in the interface, whereas bronze can only form a mechanical cohesion with diamond grains. However, when using oxygen-affine metals such as titanium, oxidizing effects could limit the strength of the bond due to insufficient adhesion between Ti-powder particles and the prevention of carbide formation. The purpose of this paper is to show the influence of the sintering atmosphere and temperature on the properties of titanium-bonded diamond grinding layers using the mechanical and thermal characterization of specimens. A higher vacuum (Δpatm = − 75 mbar) reduces the oxidation of titanium particles during sintering, which leads to higher critical bond stress (+ 38% @ Ts = 900 °C) and higher thermal conductivity (+ 3.4% @Ts = 1000 °C, Ta = 25 °C). X-ray diffraction measurements could show the formation of carbides in the cross-section of specimens, which also has a positive effect on the critical bond stress due to an adhesive bond between titanium and diamond. [ABSTRACT FROM AUTHOR]

Ultrasonic welding is a special joining process with high joining speed and good joint strength. Compared with conventional mechanical and adhesive bonding, ultrasonic welding has many advantages for joining thermoplastic composite. In this paper, the latest advances in ultrasonic welding technology for fiber-reinforced thermoplastic composites were reviewed. This paper not only compares the advantages and disadvantages of the ultrasonic welding process with other welding methods but also discusses the influence of ultrasonic welding parameters on the welding quality. The ultrasonic welding of dissimilar materials was summarized. In addition, the quality inspection and repair of ultrasonic composite welding were also discussed. Finally, the research status and development prospect of ultrasonic welding for thermoplastic composites were analyzed. [ABSTRACT FROM AUTHOR]

Continuous roll-to-roll fabrication is essential for transferring the idea of bio-inspired, fibrillar dry adhesives into large-scale, synthetic, high-performance adhesive tapes. Toward this aim, we investigated process parameters that allow us to control the morphology and the resulting adhesion of mushroom-shaped micropatterned surfaces. Flexible silicone templates enabled the replication process of the polyurethane acrylate pre-polymer involving UV-light-induced cross-linking. For this paper, we particularly tailored the polyurethane acrylate pre-polymer by adding chemical components to tune UV curing kinetics and to reduce oxygen inhibition of radicals. We found that higher intensities of the UV light and faster reaction kinetics improved the quality of the microstructures, i.e., a larger cap diameter of the mushroom tips was achieved. The polymer blend U6E4 exhibited the fastest curing kinetics, which resulted in a micromorphology similar to that of the Ni-shim master structures. Best adhesion results were obtained for adhesive tapes made from U6E4 with 116 kPa pull-off stress, 1.4 N cm−1 peel strength and 71 kPa shear strength. In addition, repeated attachment–detachment tests over 100,000 cycles demonstrated strong robustness and reusability. [ABSTRACT FROM AUTHOR]

Background: The use of hemostatic agents by general surgeons during abdominal operations is commonplace as an adjunctive measure to minimize risks of postoperative bleeding and its downstream complications. Proper selection of products can be hampered by marginal understanding of their pharmacokinetics and pharmacodynamics. While a variety of hemostatic agents are currently available on the market, the choice of those products is often confusing for surgeons. This paper aims to summarize and compare the available hemostatic products for each clinical indication and to ultimately better guide surgeons in the selection and proper use of hemostatic agents in daily clinical practice. Methods: We utilized PubMed electronic database and published product information from the respective pharmaceutical companies to collect information on the characteristics of the hemostatic products. Results: All commercially available hemostatic agents in the US are described with a description of their mechanism of action, indications, contraindications, circumstances in which they are best utilized, and expected results. Conclusion: Hemostatic products come with many different types and specifications. They are valuable tools to serve as an adjunct to surgical hemostasis. Proper education and knowledge of their characteristics are important for the selection of the right agent and optimal utilization. [ABSTRACT FROM AUTHOR]

Melanin-like nanomaterials have emerged in surface biofunctionalization in a material-independent manner due to their versatile adhesion arising from their catechol-rich structures. However, the unique adhesive properties of these materials ironically raise difficulties in their site-specific fabrication. Here, we report a method for site-specific fabrication and patterning of melanin-like pigments, using progressive assembly on an initiator-loaded template (PAINT), different from conventional lithographical methods. In this method, the local progressive assembly could be naturally induced on the given surface pretreated with initiators mediating oxidation of the catecholic precursor, as the intermediates generated from the precursors during the progressive assembly possess sufficient intrinsic underwater adhesion for localization without diffusion into solution. The pigment fabricated by PAINT showed efficient NIR-to-heat conversion properties, which can be useful in biomedical applications such as the disinfection of medical devices and cancer therapies. Melanin-like materials are becoming important for surface biofunctionalization due to versatile adhesion, but are challenging to prepare in a site-specific manner. Here, the authors report a method using progressive assembly on a catalytic template, for site-specific fabrication and patterning of melanin-like pigments. [ABSTRACT FROM AUTHOR]

The aim of this study was to clarify the effect of universal adhesive (UA) viscosity on the bond strength of resin composite to dentin prepared with Er:YAG laser. Four experimental UAs (SI-1, SI-2, SI-3, and SI-4) were developed by adding 1, 2, 3, and 4 wt/% nanosilica to BeautyBond Xtreme (Shofu), respectively. BeautyBond Xtreme was used as a control (SI-0). The viscosities of experimental UAs were measured using a B-type viscometer. After bovine mandibular anterior teeth were ground with #600 emery paper to obtain the flattened dentin surfaces, the dentin surfaces were cut thinly by irradiating the Er:YAG laser. Specimens were prepared using the respective UA and flowable resin composite and subjected to the microtensile bond strength (µTBS) test. The data from viscosity measurement and the μTBS test were statistically analyzed using the Kruskal–Wallis test. The mean values of viscosity significantly differed among the all experimental groups (p < 0.01). The μTBS of SI-1 and SI-2 was significantly higher than that of SI-0, SI-3, and SI-4 (p < 0.001). The μTBS of SI-0 was significantly lower than that of SI-4 (p < 0.001). The viscosities of the experimental universal adhesives significantly affected their bond strength to laser-cut dentin. [ABSTRACT FROM AUTHOR]

The development of analytical methods for predicting the strength characteristics of pellets produced by the compaction of fine-grained materials remains a significant and relevant area. To advance this area, the mechanisms of phase interactions in bulk media were analyzed. The analysis was then used to develop local models of adhesion processes for two basic particle interaction schemes: 'particle + particle' and 'particle + liquid phase + particle'. For each local model, the types, nature, and combination of adhesion processes that occurred simultaneously were theoretically established, and the factors and indicators that determined the occurrence and intensity of adhesive bonding were justified. The experimental studies conducted in the laboratory premises of the Nekrasov Iron and Steel Institute of the National Academy of Sciences of Ukraine were analyzed to evaluate the nature and extent of influence exerted by the selected factors, determining the adhesion processes, on changes in the strength characteristics of compacts. Considering the results obtained and the analytical dependences established for the 'particle + particle' interaction scheme, a method for predicting the strength characteristics of pellets produced from fine-grained materials with zero moisture was developed. This paper justifies the methodological conditions for experiments intended to create strong bonds within the compacts under the 'particle + liquid phase + particle' interaction scheme, taking into account the mechanical, physical, and physicochemical interaction processes between individual particles of the pelletized material and between the charge components (liquid phase). A generalized analysis of the experimental findings was carried out to estimate the range of potential adhesion processes inherent in the 'particle + liquid phase + particle' interaction scheme, identify their manifestation, study the nature of their interaction, and evaluate the effect of introducing the liquid phase into the pelletized charge, considering the applied compaction pressures. The collected array of experimental data will enable a detailed cross-correlation analysis to determine the influence of various factors on the adhesion processes and the formation of strong bonds within the compacts. The analysis will also help establish the dependence of strength characteristics of compacts on integral indicators contributing to the formation of adhesive bonds and describe the dependence by analytical methods. The results will be used to develop a method to determine the moisture content in the charge required to produce compacts with maximum strength from materials that belong to the first of the four groups of systematization. The classification of materials into specific groups of systematization is determined by their pycnometric density. [ABSTRACT FROM AUTHOR]

A new PMMA microfluidic chip fabrication method by combining laser ablation technology with low-temperature bonding using optically clear adhesive (OCA) film and liquid optically clear adhesive (LOCA) was presented in this paper. The deformation and clogging issues of the microfluidic channel were well solved. The effective bonding area ratio of microfluidic chips could be greatly improved by adjusting bonding temperature and bonding time. The crevices around the microchannels were effectively eliminated by coating treatment of LOCA. The bonding strength and waterproof of PMMA microfluidic chips coating with/without LOCA were also evaluated in this paper. [ABSTRACT FROM AUTHOR]

Archaeological textiles are suitable material for radiocarbon dating as they are mainly made of organic matter, such as plant and/or animal fibres. Radiocarbon dating provides objective age estimates of archaeological finds, based on measurements of the carbon-14 isotope present in the organic matter against an internationally used reference standard. However, the quantity and quality of carbon present in the organic matter of archaeological textiles can be affected either by the conditions under which the find was preserved (such as carbonisation, chemical change of organic matter to carbon, and mineralisation, which is the gradual replacement of organic matter by metal degradation products), or by the application of certain interventive methods of conservation (such as, consolidation and the application of organic adhesives that add foreign organic matter/carbon to the textile). Six case studies of archaeological textiles dated using the carbon-14 method are presented here. Two carbonised textile finds, two which were mineralised (one treated with adhesives in the past), and a final two which come from inhumation burials (similar to the textile previously treated with adhesives). This paper includes a discussion and review of the dating method, focusing on sample selection, sample preparation, and by evaluating the efficiency of the technique on textile finds at various states of preservation. This study shows that efficiency of the technique is highly dependable on the amount of carbon present in the finds, which does not seem to be affected by carbonisation, but is greatly affected by mineralisation and the incorporation of foreign organic matter, like synthetic consolidants. [ABSTRACT FROM AUTHOR]

Introduction and hypothesis: Articles are getting published on the use of tissue adhesive for vesicovaginal fistula. The objective is to carry out a systematic review on their effectiveness and complications. Methods: A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Two reviewers screened abstracts and full-text and extracted data independently. A narrative synthesis was conducted given the heterogeneity of studies. Results: A total of 1032 studies were identified after searching the database, and 14 articles were included in this systematic review. Of the 84 women included, 12 (14.3%) presented failure or recurrence of their fistula tract. The mean time of follow-up was 11.46 months. The average size of the fistula was 1.05 (range 0.1 to 3.9) cm. Most fistulas (81) included were vesicovaginal fistulas. Nine papers reported the usage of fibrin glue in which only three (6.5%) women reported recurrence of the fistula in a delay of 2 weeks to 26 months. The other studies used cyanoacrylate (14 women) and autologous fibrin injection from the patients' blood (31 women). No significant complications were reported. Complications reported were urinary tract infections in 3 women (3.6%), hematuria in 2 women (2.4%), overactive bladder symptoms in 6 women (7.2%) and septic pelvic thrombosis in one woman (1.2%). Conclusions: Tissue adhesive appears to be a promising alternative for management of urogenital fistulas without reported important complications. [ABSTRACT FROM AUTHOR]

Tribological properties are the significant factors to evaluate the application of polycrystalline cubic boron nitride(PcBN) with hard materials in vacuum conditions. In the current paper, the tribological properties of PcBN and WC-Co cemented carbide (YG8) during the sliding process are carried out under different loads in vacuum by ball-disk friction and wear experiments. The wear tracks of PcBN and wear scars of YG8 were characterized. The results show that the wear mechanisms of PcBN in vacuum are mainly abrasive wear and adhesive wear. Furthermore, furrows are also detected on the surface of YG8 balls due to the plowing of exfoliated cubic boron nitride. As a result, abrasive wear is the failure form of YG8 ball. The average CoF is negatively correlated with the loads. Moreover, the relationship between friction and wear is discussed deeply. The wear rate of YG8 ball is positively correlated with the load. Additionally, the wear rate ratio of PcBN and YG8 indicates that higher loads can promote the wear rate of YG8, but it also leads to the rapid wear of PcBN. The results could provide significant instructions for the regulation and control of the tribological properties of PcBN in the coming outer space exploration activities. [ABSTRACT FROM AUTHOR]

The objective was to determine the postoperative hypersensitivity of two-step Total-etch as compared to one-step Universal adhesives followed by composite restorations on 100 patients by applying Total-etch on one tooth and Universal adhesive on another tooth. The bonds and teeth were randomly selected. Postoperative hypersensitivity was recorded by visual analog scale before, immediately after, and 24 h after the restoration using cold stimulus. The Mann–Whitney test was applied for statistical comparison of postoperative hypersensitivity between the two bonds as well as for any significant difference in genders with each bond. No significant difference was found between postoperative hypersensitivity of the two adhesives before (p-value = 0.57), immediately after (p-value = 0.604), and 24 h after (p-value = 0.728) the restoration. Males showed more hypersensitivity with Total-etch as compared to females before (p-value = 0.037), immediately after (p-value = 0.047), and 24 h after the restoration (p-value = 0.022). No significant difference was found between gender and Universal adhesive at all three stages (p-value > 0.05). The results suggest no significant difference in postoperative hypersensitivity between the two materials when good sample size and proper technique were observed along with the removal of bias like different patients having different pain perceptions and multiple operators having different operating skills. Males showed more hypersensitivity to Total-etch. Trial registration number: Australian New Zealand Clinical Trials. Registry number: ACTRN12622001213730. (Retrospectively registered: 09/09/2022). [ABSTRACT FROM AUTHOR]

Adhesives, which also comprise of terms like bonding agents, glues and gums, are substances which possess the ability to attach to various substrates and hence can be used to join materials. They find use for bonding of various substrates such as wood, metals, plastics and find applications in automotive, construction sectors, electrical or thermal conductivity applications, and dentistry among others. Adhesives are mainly composed of polymers and different additives, of which, one is fillers. Fillers are solid substances which are insoluble in the adhesive, and they are incorporated in adhesives to reduce cost, modify mechanical properties, increase viscosity, improve electrical and/or thermal conductivity, obtain better adhesion, etc. Some types of fillers utilized are bio-based (cellulose nanoparticles, tree bark powders); carbon-based (carbon black, carbon nanotubes, diamond, graphene); ceramics (aluminium oxide, boron nitride, iron carbide, silicon carbide); metallic (aluminium, aluminium oxide, copper, silver, titanium dioxide); silicon-based (layered silicate, silica); or hybrid (consisting of more than one type of filler). Both the type and the amount of filler added will affect the properties of the adhesive. Several adhesives having diverse uses have been considered in this study. The paper reviews in detail the effect of a number of fillers on the properties of the different adhesives. [ABSTRACT FROM AUTHOR]

In this paper, we consider a laminated beam model which is given by two identical uniform layers on top of each other, taking into account that an adhesive of small thickness is bonding the two surfaces and produces an interfacial slip. With one internal frictional or viscoelastic damping in the second equation and one boundary damping modulated by time-dependent coefficients, we establish uniform stability results without imposing any conditions on the physical parameters of the system. [ABSTRACT FROM AUTHOR]

Adhesive joints have been an effective alternative to conventional mechanical fasteners for joining materials in the aerospace and automotive industries. Although adhesive joints have various advantages, including uniform stress distribution, lower weight, improved corrosion tolerance, and design flexibility, there can be various defects in adhesive joints, which have limited wider application. This paper investigates the effect of a contaminant on the chemical and mechanical properties of the epoxy-adhesive and seeks to determine if a second harmonic generation method can reliably detect and characterize the degree of contamination in the epoxy-adhesive. A contact based ultrasonic through-transmission method was used to measure nonlinearity and then the nonlinearity parameter was calculated using the measured fundamental and second harmonic frequency components in the signals. It was found that there is higher sensitivity to contaminant concentration, up to 1.5%, of the nonlinearity parameter than that for the sound velocity. These data were also found to correlate with changes in the mechanical hardness, which was measured by the Rockwell hardness testing, with different four levels of contamination. Differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA) were also conducted to assess the effect of the contaminant on thermal properties of the epoxy-adhesive. The DSC and TGA techniques were used to evaluate the curing reaction and the thermal stability of the epoxy-adhesive respectively. [ABSTRACT FROM AUTHOR]

The laser shock adhesive-clinching (LSAC) is an original material joining technique that combines the advantages of clinch-bonded hybrid joining and laser shock clinching, in which two metal foils are bonded by adhesive and clinched by laser shock simultaneously. In this paper, the LSAC joints are manufactured by 1060 Al foils, Henkel EP 5055 adhesive, and perforated 304 stainless steel sheets. Through experiments and FEM simulations, the LSAC process and the deformation of LSAC joints under shear loads are analyzed, and the effect of adhesive on LSAC joint manufacturing is investigated. The results show that bulging is the dominant deformation behavior during LASC, and the cured adhesive with thin thickness is beneficial to the subsequent clinching process. The shear strength of the LSAC joint is greatly enhanced compared to the pure clinched and pure bonded joints. The shear failure process of the LSAC joint is adhesive degumming first, then the interlock separating. [ABSTRACT FROM AUTHOR]

This paper describes the fabrication of a vertically-allocated SU-8 cantilever in a closed fluidic channel. The difficulties to fabricate the vertically-allocated SU-8 cantilever inside the closed channel mainly lie in which kinds of sacrificial layers under the cantilever and sealing methods for enclosing the channel are utilized for the movability of the cantilever. To obtain a suitable sacrificial layer and high sealing quality, the selectivity of sacrificial layers and the sealing conditions based on the SU-8 adhesive are discussed in this paper. The experiments to test different photoresist lead to the conclusion that AZ 5214E is adequate for the sacrificial layer. Also, the bonding results indicate that the thickness of the uncrosslinked SU-8 solid layer is the most important factor which affects the formation of a proper gap between the top coverglass and the SU-8 cantilever. The photos of the movement of the cantilever also show that the free-standing SU-8 cantilever is successfully fabricated by releasing the suitable sacrificial layer and is allocated inside the closed channel by the method of SU-8 adhesive. The fabrication method in this paper is also useful for other microfluidic applications. [ABSTRACT FROM AUTHOR]

Adhesive bonding of CFRP is one major approach to join this class of compound materials with other components, e.g., metals. The necessity to clean CFRP parts after fabrication and generate a bond-ready interface without damaging the implemented fibers demands a gentle and highly reproducible surface treatment. Lasers operating in the UV region are one promising technique for that topic. Yet, the factors influencing the adhesion properties of laser-treated CFRP are not sufficiently understood. The present paper describes the influence of nanosecond-pulsed laser parameters on CFRP treatment effects in context of adhesive bonding properties. A special focus was given on the distribution and avoidance of re-deposition effects by laser parameter selection. Furthermore, the effect of laser-induced fiber exposure was analyzed. Re-deposition and fiber exposure were complementarily discussed with chemical analyses of the surface composition after laser treatment in the context of bond strength studies under Mode I loading. It was found that both effects, i.e., re-deposition on the treated surface and laser-induced fiber exposure by overtreatment, result in lower strength values compared to an "optimized" treatment exhibiting none of the descripted conditions. [ABSTRACT FROM AUTHOR]

Filtration and separation of airborne nanoparticles remains a challenge due to their unique properties. This paper reports a molecular dynamics study on the size-dependent coefficient of restitution (CoR) of sub-10 nm nanoparticles on a surface with varying stickiness. The results show the collision regime changes from quasi-elastic or viscoelastic to plastic deformation, with increasing the particle impact velocity. For purely repulsive collisions, CoR of these nanoparticles generally exhibits a similar trend, but they become fluctuating for smaller nanoparticles. When the impact velocity reaches the respective yield velocity, plastic deformation takes place and CoR starts to decrease. During the sticky collisions, the nanoparticles around 2 nm acquire an increased impact velocity higher than their yield velocities, resulting in plastic deformation and reduced CoR for all initial velocities. Larger nanoparticles follow the same trend of the CoR curve for purely repulsive collisions, although their CoR values become smaller than the repulsive collision. [ABSTRACT FROM AUTHOR]

The application of adhesives in modern timber engineering often introduces moisture into the wood, leading to permanent residual stresses after hardening. This paper proposes a novel approach to assess these residual stresses by using wooden bilayers as a reporter system. For thin bilayers, moisture-induced stresses lead to pronounced visible flexion that can be used to identify the stress-driving parameters of the adhesive's gelation process. These parameters depend solely on the wood/adhesive combination and are inversely determined by fitting a finite element method model on the experimentally obtained flexion state. In a subsequent step, the determined parameters are used to calculate the residual stresses in the adhesive bondline of cross-laminated timber plates, emphasizing this approach's scale independence and general applicability to larger scale structures. All combinations of European beech and Norway spruce with the adhesives Melamine–Urea–Formaldehyde (MUF), Phenol–Resorcinol–Formaldehyde (PRF), and Polyurethane (PUR) were investigated. [ABSTRACT FROM AUTHOR]

This article explores a novel approach to inhibit local premature failures in cold-formed steel (CFS) beams and enhance their flexural capacity by introducing external web stiffeners to buckling prone regions. An experimental and finite element investigation on the behaviour of doubly symmetric CFS built-up channel beams with adhesively bonded glass-fiber reinforced polymer (GFRP) stiffeners is presented in this paper. Unlike previous attempts, where flat plates have been used, the results of pultruded T-shaped GFRP stiffeners on the flexural capacity and local failure inhibition of the CFS beams are presented. The viability of suggested strengthening arrangement is assessed by comparing the results from CFS beams strengthened with steel stiffeners of equivalent stiffness. One control and six reinforced beams, stiffened with different configurations of both steel and GFRP stiffeners in the moment span, were tested up to failure under four-point bending. The change in the mode of failure from buckling at discrete regions to global failures with an improvement in the flexural capacity by up to 39% was achieved using adhesively bonded external stiffeners in the present study. It can be concluded that adhesively bonded GFRP stiffeners provide a cost-effective and adequate alternative to enhance the flexural performance and inhibit the local failures in thin-walled beams. Finite element models were developed and verified against test results. FE models were found to be capable of predicting the ultimate capacity and failure of stiffened beams with fair accuracy. [ABSTRACT FROM AUTHOR]

Understanding tool wear characteristics in machining SiC particle–reinforced aluminum matrix (SiCp/Al) composites is crucial for tool structure design and promising wide application of the material. This paper comprehensively studied the effect of particle volume fractions (PVFs) on the wear characteristics for the multi-coated cutting tool in turning SiCp/Al composites. Tool wear curves for machining SiCp/Al/15%p, 30%p, and 45%p were depicted. Importantly, the tool wear characteristics for full wear stages on rake and flank face were obtained for the first time. Results show that the increase of PVFs accelerated the removal of coating and the peeling of the adhesive layer. Different appearances of the adhesive wear on the rake face were found, where the deposited and adhesive layers were in turning SiCp/Al/15%p, and deposited layer and microchip adhesion were in turning SiCp/Al/30%p and 45%p. Specifically, strong protection of adhesive layer prevented the formation of coating shedding and crater wear on the rake face in turning SiCp/Al/15%p. The wear characteristics on the flank face were characterized by adhesive wear, abrasive wear, and coating shedding, which remained consistent whether in different PVFs or at different wear stages. [ABSTRACT FROM AUTHOR]

In recent times, the use of natural and harmless products for the environment and restorer is taking place in the field of Cultural Heritage restoration. In this sense, wheat, rice and corn starches as adhesives, have suitable characteristics without toxicity risks. A new starch in this field, is the Kudzu, an almost pure compound (99.5% starch) that is processed by a natural way from a plant called Pueraria lobata. This is a preliminary study of the potential use of Kudzu starch for the restoration of Cultural Heritage, focusing, firstly, in its capacity as adhesive through a comparative evaluation with common starches. The accelerated aging process carried out proved that Kudzu ensures optimal chromatic behaviour. On the other hand, the main problem in starch paste is the biological colonization. The daidzein, a natural antimicrobial compound implicit in Kudzu starch, confirmed the resistance to microorganism in this preliminary approach. The evaluation of the adhesive capacity, and the reversibility of the starches, suggest that Kudzu starch is a valid adhesive in the field of paper restoration. Thus, the potential of this starch in the conservation of Cultural Heritage is evidenced and its use as cleaner, resistance to biological colonization and consolidant is promising. [ABSTRACT FROM AUTHOR]

In the context of lightweight design and modern hybrid technologies, the importance of structural and soft adhesives in industrial applications is increasing. Therefore, this paper examines a relatively soft polyurethane adhesive characterized by showing nonlinear viscoelastic behavior at room temperature and enduring large deformations. It is well suited for applications under dynamic loadings and can compensate gap changes generated by materials with different thermal expansion coefficients. Theoretically, the examined one-component polyurethane adhesive can be cured either thermally or through humidity, resulting in the same mechanical characteristics. Comparing both curing reactions, humidity curing is much slower than thermal curing. The latter can be controlled through the temperature, which may be applied through heating rates of up to 150 K min - 1 . However, in comparison with metals polyurethane conducts the heat with a much smaller rate which results in high temperature gradients within the adhesive layer. This paper focuses on the modeling of a fast-curing polyurethane adhesive under consideration of the changes in density and thermomechanical material properties induced by thermal curing. Therefore, the material properties need to be observed throughout the thermal curing process, from the uncured fluid to the cured rubber material. In the long term, the accurate prediction of the materials behavior will ultimately facilitate the optimization of the curing process. [ABSTRACT FROM AUTHOR]

Adhesive work holding can be used to minimize clamping distortion and provide greater access to a work piece during machining. This paper proposes shear and tensile strength criteria to evaluate the work holding strength of adhesive grippers and definition of a strength safety coefficient of adhesive grippers. It also demonstrates a case study of work holding design with an UV adhesive for a grinding process based on a strength criteria explained in the paper. A test rig has been designed and manufactured to assess the capability of an adhesive work holding material. Tests include measurement of strength and repeatability of adhesion under different film thicknesses, curing times and pre-cleaning methods. The test shows the strength repeatability is less than ± 20%, which is good enough for many work holding applications. A shear-tensile combined strength can be evaluated by the strength sphere in a fixture design of a specific part geometry for production by the combined safety coefficient. Following the test rig assessment, a fixture has been designed with 3 grippers to demonstrate the adhesive for a grinding process with a simple part geometry. The method has a high potential for application in industry, and is not limited to the given part geometry and machining method. The grinding test shows that the adhesive work holding is strong enough for the application and that similar results can be expected for milling and turning with a good gripper arrangement. [ABSTRACT FROM AUTHOR]

This paper describes a study of deformation of an ideal elastoplastic adhesive layer of a sample in the form of an elastic double-cantilever beam. The integral values are determined for a number of adhesives with account for all diagonal stress tensor components in the layer. It is shown that the integral value is significantly affected by the plane problem type in the case where an elastic-plastic model of layer deformation is applied. As demonstrated in the study, compressive stresses may be present during normal fracture in the irreversible deformation region of the adhesive in a plane stressed state. [ABSTRACT FROM AUTHOR]

Water-based acrylic pressure-sensitive adhesives (PSA) are a common component of disposable products such as tapes, labels, and packaging. Such adhesives are generated from fossil-derived monomers and additives and persist in the environment due to their low biodegradability. Furthermore, they can interfere with the recycling and remediation of products they interact with, such as plastic and paper products. Although touted as a promising remedy to these issues, adhesive polymers generated using renewable and degradable monomers tend to fall short regarding performance and cost. This study reports on the fungal degradation behaviors of hybrid PSAs copolymerized mainly from traditional acrylics and lactide-based macromonomers. These structures provide high performance at a reasonable cost and represent an alternative approach to addressing environmental concerns. Evaluating the biodegradability of these hybrid PSAs involved solid and liquid cultures using 53 unique fungal species. Nearly 50% (n = 23) of the screened species showed PSA-degrading capacities of varying degrees, including Trametes versicolor and Pestalotiopsis microspora, providing roughly complete (> 96%) polymer removal in liquid cultures. Fungal degradation of cast adhesive films was monitored using evolved CO2 and mass loss and confirmed through scanning electron microscopy and spectral analysis (FTIR). Enzyme assays, namely laccases, lipases, and proteases, showed a high correlation with the observed biodegradation rates, suggesting that hydrolytic and oxidative enzymes were likely factors driving latex degradation. These results demonstrate that the high-performing hybrid formulation is degradable by fungi. While a portion of the studied adhesive was synthesized using petroleum-derived monomers, this could serve as a bridge technology, helping to usher in more sustainable disposable consumer products until a time comes when all components are renewably sourced. [ABSTRACT FROM AUTHOR]