Pub Date : 2022-09-11DOI: 10.1080/00218464.2022.2122818
Tianmao Lai, Siyuan Qiu, Runsheng Wang
ABSTRACT Piezo velocity dependence of adhesion force is contradictory and requires clarification in the literature. The dependence was investigated with the measurements between a silica cantilever and surfaces with different materials in a humid condition on an atomic force microscope (AFM). The results demonstrate that the velocity dependence is correlated with materials. Depending on those surfaces, there are various behaviors: (1) independence below a critical velocity and decreasing above the critical velocity; (2) having large values at low velocities and independence at high velocities; (3) independence in the entire velocity range; (4) independence at low velocities and having large values at high velocities; (5) increasing exponentially. The decrease at high velocities was attributed to the pull-off instability in a water bridge with low viscosity. The large values at high velocities were attributed to the dynamic viscous force with high viscosity. Independence in the entire velocity range was attributed to the compromise between the pull-off instability and viscous force with moderate viscosity. The exponential increase was ascribed to a crack propagation process. The results may add to our knowledge of adhesion forces, propose selection recommendations of AFM parameters, and improve the design of relevant small-scale devices.
{"title":"Material-related and various dependences of adhesion force on piezo velocity revealed on an AFM at moderate humidity","authors":"Tianmao Lai, Siyuan Qiu, Runsheng Wang","doi":"10.1080/00218464.2022.2122818","DOIUrl":"https://doi.org/10.1080/00218464.2022.2122818","url":null,"abstract":"ABSTRACT Piezo velocity dependence of adhesion force is contradictory and requires clarification in the literature. The dependence was investigated with the measurements between a silica cantilever and surfaces with different materials in a humid condition on an atomic force microscope (AFM). The results demonstrate that the velocity dependence is correlated with materials. Depending on those surfaces, there are various behaviors: (1) independence below a critical velocity and decreasing above the critical velocity; (2) having large values at low velocities and independence at high velocities; (3) independence in the entire velocity range; (4) independence at low velocities and having large values at high velocities; (5) increasing exponentially. The decrease at high velocities was attributed to the pull-off instability in a water bridge with low viscosity. The large values at high velocities were attributed to the dynamic viscous force with high viscosity. Independence in the entire velocity range was attributed to the compromise between the pull-off instability and viscous force with moderate viscosity. The exponential increase was ascribed to a crack propagation process. The results may add to our knowledge of adhesion forces, propose selection recommendations of AFM parameters, and improve the design of relevant small-scale devices.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44077955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-07DOI: 10.1080/00218464.2022.2106132
Leo Škec, G. Alfano
ABSTRACT We present an experimental and numerical study of the rate dependence of the mode-I failure of adhesive joints, focussing on aluminium plates bonded with Araldite® 2015. For the experimental part, we tested 24 double-cantilever beams (DCB) at six different prescribed speeds, from 0.1 to 5000 mm/min. The numerical simulations use a previously proposed cohesive-zone model (CZM) based on fractional viscoelasticity and a novel finite element combining a Timoshenko beam and an interface element. The CZM had previously been validated for a rubber interface, so here we present a procedure to identify its input parameters and validate its capability to predict the failure of joints made with an epoxy adhesive. An effective procedure is also developed to evaluate the dependence of the fracture energy on the crack speed without experimentally measuring the crack speed. The adhesive response was found to be markedly rate dependent. Within the range of tested speeds, the fracture energy of the adhesive more than doubles its value and the shape of the ‘fracture energy-crack speed’ curve resembles a sigmoidal shape, but more tests are needed at higher speeds to better determine the maximum value of the fracture energy and the actual shape of the complete curve.
{"title":"Experimental and numerical study of rate-dependent mode-I failure of a structural adhesive","authors":"Leo Škec, G. Alfano","doi":"10.1080/00218464.2022.2106132","DOIUrl":"https://doi.org/10.1080/00218464.2022.2106132","url":null,"abstract":"ABSTRACT We present an experimental and numerical study of the rate dependence of the mode-I failure of adhesive joints, focussing on aluminium plates bonded with Araldite® 2015. For the experimental part, we tested 24 double-cantilever beams (DCB) at six different prescribed speeds, from 0.1 to 5000 mm/min. The numerical simulations use a previously proposed cohesive-zone model (CZM) based on fractional viscoelasticity and a novel finite element combining a Timoshenko beam and an interface element. The CZM had previously been validated for a rubber interface, so here we present a procedure to identify its input parameters and validate its capability to predict the failure of joints made with an epoxy adhesive. An effective procedure is also developed to evaluate the dependence of the fracture energy on the crack speed without experimentally measuring the crack speed. The adhesive response was found to be markedly rate dependent. Within the range of tested speeds, the fracture energy of the adhesive more than doubles its value and the shape of the ‘fracture energy-crack speed’ curve resembles a sigmoidal shape, but more tests are needed at higher speeds to better determine the maximum value of the fracture energy and the actual shape of the complete curve.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49068473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-06DOI: 10.1080/00218464.2022.2121649
J. Wirries, Till Vallée, Martin Rütters
ABSTRACT Prediction of stresses in adhesively bonded joints requires high effort in determination of relevant material properties, which change during cure. In addition, the computational effort using complex viscoelastic finite element (FE) models impends efficient prediction of stress build-up. Rotational and oscillatory rheometry can help to reduce the experimental effort by measuring of modulus of elasticity (MoE) and axial shrinkage along curing. In this publication, shrinkage, development of MoE and Poisson’s ratio of a curing adhesive were numerically modelled between two parallel rheometer plates in order to calculate cure-induced stresses using finite element analysis (FEA). To identify effects of different material properties on stress distribution, a parameter study was carried out and the reciprocal influence of the varied parameters was investigated. Consequently, resulting stresses within the adhesive layer and occurring deformations were investigated with respect to curing time as well as their location. The results showed that final shrinkage and MoE need to be considered not only in final values but also in terms of course of shrinkage and reaction. Stress build-up led to deformation of the rheometer plates, which has to be considered when using rheometry for determination of cure shrinkage.
{"title":"Cure-induced stress build-up in adhesives: model building and parameter studies","authors":"J. Wirries, Till Vallée, Martin Rütters","doi":"10.1080/00218464.2022.2121649","DOIUrl":"https://doi.org/10.1080/00218464.2022.2121649","url":null,"abstract":"ABSTRACT Prediction of stresses in adhesively bonded joints requires high effort in determination of relevant material properties, which change during cure. In addition, the computational effort using complex viscoelastic finite element (FE) models impends efficient prediction of stress build-up. Rotational and oscillatory rheometry can help to reduce the experimental effort by measuring of modulus of elasticity (MoE) and axial shrinkage along curing. In this publication, shrinkage, development of MoE and Poisson’s ratio of a curing adhesive were numerically modelled between two parallel rheometer plates in order to calculate cure-induced stresses using finite element analysis (FEA). To identify effects of different material properties on stress distribution, a parameter study was carried out and the reciprocal influence of the varied parameters was investigated. Consequently, resulting stresses within the adhesive layer and occurring deformations were investigated with respect to curing time as well as their location. The results showed that final shrinkage and MoE need to be considered not only in final values but also in terms of course of shrinkage and reaction. Stress build-up led to deformation of the rheometer plates, which has to be considered when using rheometry for determination of cure shrinkage.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46202384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Research on adhesives made from recycled and renewable biomass materials is an important direction in wood material industry. The eco-friendly plywood adhesive named as SADP adhesive, according to its composition (Sucrose and Ammonium Dihydrogen Phosphate), developed in our research group previously has good bonding performance but bleed-through veneer. In previous studies, we found that plant proteins, such as defatted soybean flour (DSF) and dephenolized cottonseed protein (DCP) material could improve this phenomenon. However, although DCP considerably promoted the bonding performance of the SADP adhesive, DSF did not. Therefore, this study will determine the optimal preparation and hot pressing conditions of the developed adhesive, and investigate the curing mechanism. First, the evaluation of the effects of the plant protein type, mass ratio, hot pressing temperature and time on the bonding performance of these adhesives revealed that plywood prepared by hot pressing at 170°C for 7 min using DCP/SADP-1/3 ratio as adhesive had the highest wet shear strength (1.17 MPa). Additionally, the comparative analysis of the two plant proteins showed that the DCP has a higher crude protein content, more tryptophan and arginine, which might be the reason for its better bonding performance with SADP solution. Second, in the analysis of curing behavior, the result of TG-DSC analysis corresponded to the insoluble mass proportion measurement, indicating that the optimal curing temperature of DCP/SADP-1/3 adhesive was about 170°C. In addition, ATR FT-IR analysis indicated that the curing mechanism was complex, involving caramelization and Maillard reaction to form a dense crosslinking structure, with dimethylene ether bridge as the main linkage. Finally, a comparison of various scanning electron microscopy (SEM) chromatograms revealed that, with the increase of the amount of DCP added, the cured adhesive became less porous and had smoother surface, which further confirmed that DCP and SADP solution formed a novel network crosslinked structure after curing process. Furthermore, compared with the wet shear strength of SADP adhesive (0.88 MPa), the plywood prepared using the novel DCP/SADP-1/3 adhesive (1.17MPa) was increased by 33%.
{"title":"Improvement of the bonding performance of sucrose and ammonium dihydrogen phosphate adhesive by addition of dephenolized cottonseed protein","authors":"Qiumu Lin, Xue Zhang, Wenqian Cai, Xuanyuan Xia, Chengsheng Gui, Zhongyuan Zhao","doi":"10.1080/00218464.2022.2107905","DOIUrl":"https://doi.org/10.1080/00218464.2022.2107905","url":null,"abstract":"ABSTRACT Research on adhesives made from recycled and renewable biomass materials is an important direction in wood material industry. The eco-friendly plywood adhesive named as SADP adhesive, according to its composition (Sucrose and Ammonium Dihydrogen Phosphate), developed in our research group previously has good bonding performance but bleed-through veneer. In previous studies, we found that plant proteins, such as defatted soybean flour (DSF) and dephenolized cottonseed protein (DCP) material could improve this phenomenon. However, although DCP considerably promoted the bonding performance of the SADP adhesive, DSF did not. Therefore, this study will determine the optimal preparation and hot pressing conditions of the developed adhesive, and investigate the curing mechanism. First, the evaluation of the effects of the plant protein type, mass ratio, hot pressing temperature and time on the bonding performance of these adhesives revealed that plywood prepared by hot pressing at 170°C for 7 min using DCP/SADP-1/3 ratio as adhesive had the highest wet shear strength (1.17 MPa). Additionally, the comparative analysis of the two plant proteins showed that the DCP has a higher crude protein content, more tryptophan and arginine, which might be the reason for its better bonding performance with SADP solution. Second, in the analysis of curing behavior, the result of TG-DSC analysis corresponded to the insoluble mass proportion measurement, indicating that the optimal curing temperature of DCP/SADP-1/3 adhesive was about 170°C. In addition, ATR FT-IR analysis indicated that the curing mechanism was complex, involving caramelization and Maillard reaction to form a dense crosslinking structure, with dimethylene ether bridge as the main linkage. Finally, a comparison of various scanning electron microscopy (SEM) chromatograms revealed that, with the increase of the amount of DCP added, the cured adhesive became less porous and had smoother surface, which further confirmed that DCP and SADP solution formed a novel network crosslinked structure after curing process. Furthermore, compared with the wet shear strength of SADP adhesive (0.88 MPa), the plywood prepared using the novel DCP/SADP-1/3 adhesive (1.17MPa) was increased by 33%.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47095394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-31DOI: 10.1080/00218464.2022.2107426
Di Cai, Yi Wen, J. Qiu, Bo Sun, Weili Zhang, Youbing Li, T. Xia, Chaolong Yang
ABSTRACT Polycarbonate/aluminum alloy hybrids were prepared using a homemade ultrasound-assisted hot pressing molding (UAHPM) technique, and their properties and structures at the plastic-metal interface were also investigated. The aluminum alloy surface was chemically etched and anodized to form micron and nano-holes structures. The joint strength of 21.58 MPa was achieved at the optimum molding process by optimizing the process parameters of ultrasonic hot compression molding. The specific structure and morphology of the polycarbonate/aluminum hybrid material bonding layer were observed by field emission scanning electron microscopy (FE-SEM) using the ultrathin sectioning technique, and the plastic embedding depth reached about 3.8 µm under the optimal process conditions. X-ray photoelectron spectroscopy (XPS) analysis revealed that the bonding layer not only has a micro-nano interlocking structure but also forms an Al-O-C chemical bonding interaction. The plastic in the bonding layer was exposed by dissolving the aluminum alloy of the joint, and the filling form of the plastic in the micro-nanoholes was directly observed.
{"title":"Mechanical property and structure of polycarbonate /aluminum alloy hybrid prepared by ultrasound-assisted hot-pressing technology","authors":"Di Cai, Yi Wen, J. Qiu, Bo Sun, Weili Zhang, Youbing Li, T. Xia, Chaolong Yang","doi":"10.1080/00218464.2022.2107426","DOIUrl":"https://doi.org/10.1080/00218464.2022.2107426","url":null,"abstract":"ABSTRACT Polycarbonate/aluminum alloy hybrids were prepared using a homemade ultrasound-assisted hot pressing molding (UAHPM) technique, and their properties and structures at the plastic-metal interface were also investigated. The aluminum alloy surface was chemically etched and anodized to form micron and nano-holes structures. The joint strength of 21.58 MPa was achieved at the optimum molding process by optimizing the process parameters of ultrasonic hot compression molding. The specific structure and morphology of the polycarbonate/aluminum hybrid material bonding layer were observed by field emission scanning electron microscopy (FE-SEM) using the ultrathin sectioning technique, and the plastic embedding depth reached about 3.8 µm under the optimal process conditions. X-ray photoelectron spectroscopy (XPS) analysis revealed that the bonding layer not only has a micro-nano interlocking structure but also forms an Al-O-C chemical bonding interaction. The plastic in the bonding layer was exposed by dissolving the aluminum alloy of the joint, and the filling form of the plastic in the micro-nanoholes was directly observed.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44228150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-21DOI: 10.1080/00218464.2022.2102902
Sascha Voß, M. Voß
ABSTRACT To ensure the desired mechanical properties of adhesively bonded components, maintaining the prescribed mixing quality, i.e. mixing ratio and evenness, of two-component (2K) adhesives is essential. Although different studies proved that mixing errors may exert a negative impact on the bonding result, there are currently no methods available that would allow for continuous monitoring thereof during inline dosing processes. A way out of associated issues is offered by the Electrical Capacitance Tomography (ECT), which enables practitioners to map spatial material distributions and mixing ratios by measuring the capacitances of different media, including adhesives. Therefore, the aim of the study was to investigate the ECT’s potential to be used for 2K mixture quality control. Due to the complexity of the matter, the presentation is split into two papers. In this 1st part, all preliminary experimental and analytical work aiming to determine polymer characteristics, above all permittivity, ε, needed to evaluate whether a respective 2K adhesive may be ECT-monitored is presented. For that, a permittivity measurement device (PMD) was developed, which allows for a fast and efficient determination of adhesive permittivities. Subsequently, the PMD was validated with reference dielectrics and then used to determine the permittivities of the components of 16 commercially available 2K adhesives (epoxies and polyurethanes). Finally, the relationship between permittivity and mixing ratio was investigated for a sub-set of four representative ECT-suitable adhesives. It was found that a wide variety of 2K polymers may principally be controlled by ECT and that the relationship between mixing ratio and mixture permittivity can be described by general analytical theories from the literature. As a result, preliminary experimental effort aiming to assess the adhesive suitability for inline ECT-monitoring could be significantly reduced. The latter experiments will be the topic of the 2nd part of the study.
{"title":"Controlling the mixing quality of 2K adhesives by means of electrical capacitance tomography – Part I: necessary polymer characteristics","authors":"Sascha Voß, M. Voß","doi":"10.1080/00218464.2022.2102902","DOIUrl":"https://doi.org/10.1080/00218464.2022.2102902","url":null,"abstract":"ABSTRACT To ensure the desired mechanical properties of adhesively bonded components, maintaining the prescribed mixing quality, i.e. mixing ratio and evenness, of two-component (2K) adhesives is essential. Although different studies proved that mixing errors may exert a negative impact on the bonding result, there are currently no methods available that would allow for continuous monitoring thereof during inline dosing processes. A way out of associated issues is offered by the Electrical Capacitance Tomography (ECT), which enables practitioners to map spatial material distributions and mixing ratios by measuring the capacitances of different media, including adhesives. Therefore, the aim of the study was to investigate the ECT’s potential to be used for 2K mixture quality control. Due to the complexity of the matter, the presentation is split into two papers. In this 1st part, all preliminary experimental and analytical work aiming to determine polymer characteristics, above all permittivity, ε, needed to evaluate whether a respective 2K adhesive may be ECT-monitored is presented. For that, a permittivity measurement device (PMD) was developed, which allows for a fast and efficient determination of adhesive permittivities. Subsequently, the PMD was validated with reference dielectrics and then used to determine the permittivities of the components of 16 commercially available 2K adhesives (epoxies and polyurethanes). Finally, the relationship between permittivity and mixing ratio was investigated for a sub-set of four representative ECT-suitable adhesives. It was found that a wide variety of 2K polymers may principally be controlled by ECT and that the relationship between mixing ratio and mixture permittivity can be described by general analytical theories from the literature. As a result, preliminary experimental effort aiming to assess the adhesive suitability for inline ECT-monitoring could be significantly reduced. The latter experiments will be the topic of the 2nd part of the study.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46672123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-14DOI: 10.1080/00218464.2022.2099740
Linqing Xie, Wei Cao, Chengjun Sun
ABSTRACT As an important model organism for the study of marine bioadhesion, mussels have attracted extensive attention and research. Recent studies have shown that lipids are involved in mussel bioadhesion. To investigate the role of lipids in the mussel adhesion process, we use a Quartz Crystal Microbalance with Dissipation (QCM-D) to investigate the dynamic adhesion process of mussel foot proteins (Mefp-1) on different substrates in the presence of lipids by monitoring the changes of Mefp-1 adsorption in real-time. The results show that Mefp-1 binds less to polar hydrophilic SiO2 substrate than to Au substrate, and the introduction of C16:0 palmitic acid significantly promotes the binding of Mefp-1 to different substrates. With increasing palmitic acid concentration, more Mefp-1 would bind to the substrate. According to the adsorption model analysis, palmitic acid may promote the adhesion and binding of Mefp-1 by changing the hydration environment of the adhesion interface in the adhesion process. This study on the effects of fatty acids on Mfp-1 adhesion can help us better understand the bioadhesion mechanisms of mussels, and provide insight for marine antifouling research.
{"title":"The study of fatty acid mediated Mefp-1 adsorption by Quartz Crystal Microbalance with Dissipation","authors":"Linqing Xie, Wei Cao, Chengjun Sun","doi":"10.1080/00218464.2022.2099740","DOIUrl":"https://doi.org/10.1080/00218464.2022.2099740","url":null,"abstract":"ABSTRACT As an important model organism for the study of marine bioadhesion, mussels have attracted extensive attention and research. Recent studies have shown that lipids are involved in mussel bioadhesion. To investigate the role of lipids in the mussel adhesion process, we use a Quartz Crystal Microbalance with Dissipation (QCM-D) to investigate the dynamic adhesion process of mussel foot proteins (Mefp-1) on different substrates in the presence of lipids by monitoring the changes of Mefp-1 adsorption in real-time. The results show that Mefp-1 binds less to polar hydrophilic SiO2 substrate than to Au substrate, and the introduction of C16:0 palmitic acid significantly promotes the binding of Mefp-1 to different substrates. With increasing palmitic acid concentration, more Mefp-1 would bind to the substrate. According to the adsorption model analysis, palmitic acid may promote the adhesion and binding of Mefp-1 by changing the hydration environment of the adhesion interface in the adhesion process. This study on the effects of fatty acids on Mfp-1 adhesion can help us better understand the bioadhesion mechanisms of mussels, and provide insight for marine antifouling research.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42171483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-13DOI: 10.1080/00218464.2022.2100254
E. Ernault, J. Diani, Q. Schmid
ABSTRACT Two hot melt pressure sensitive adhesives have been submitted to bonded joint creep tests. An amorphous and a semicrystalline adhesives have been considered for their different microstructures leading to different mechanical behaviors. The adhesives are referred as soft since their glass transition temperatures stand well below the temperatures of applications, resulting in low stiffnesses. The creep of structural joints has been characterized with single-lap joint tests. Two types of adherends were considered either glass or stainless steel. The adherend roughness and the adhesive wettability have been characterized before testing. The significant stiffness contrast between the stiff adherends and the soft adhesives promoted homogeneous simple shear creeps. The amorphous adhesive showed creep behaviors that depend on the type of substrates, showing that the joint viscoelasticity could not be predicted knowing the bulk adhesive viscoelasticity only, unlike for stiff adhesives as recently reported in the literature. Finally, the single-lap joint creep behaviors of both adhesives on the same glass adherends were compared and discussed at the light of their different microstructures inducing different mechanical behaviors.
{"title":"Single-lap joint creep behaviour of two soft adhesives","authors":"E. Ernault, J. Diani, Q. Schmid","doi":"10.1080/00218464.2022.2100254","DOIUrl":"https://doi.org/10.1080/00218464.2022.2100254","url":null,"abstract":"ABSTRACT Two hot melt pressure sensitive adhesives have been submitted to bonded joint creep tests. An amorphous and a semicrystalline adhesives have been considered for their different microstructures leading to different mechanical behaviors. The adhesives are referred as soft since their glass transition temperatures stand well below the temperatures of applications, resulting in low stiffnesses. The creep of structural joints has been characterized with single-lap joint tests. Two types of adherends were considered either glass or stainless steel. The adherend roughness and the adhesive wettability have been characterized before testing. The significant stiffness contrast between the stiff adherends and the soft adhesives promoted homogeneous simple shear creeps. The amorphous adhesive showed creep behaviors that depend on the type of substrates, showing that the joint viscoelasticity could not be predicted knowing the bulk adhesive viscoelasticity only, unlike for stiff adhesives as recently reported in the literature. Finally, the single-lap joint creep behaviors of both adhesives on the same glass adherends were compared and discussed at the light of their different microstructures inducing different mechanical behaviors.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49155170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-04DOI: 10.1080/00218464.2022.2097077
Yiwen Xu, Yali Ji, Jinghong Ma
ABSTRACT Mussel-inspired tissue adhesives have been widely studied in recent years because of their excellent underwater adhesion. Our recent study has synthesized a series of tissue adhesives with citric acid, dopamine, 1,8-octanediol and poly(ethylene oxide) (PEO), and found that amphiphilic adhesives showed an efficient underwater adhesion mechanism. Poly(propylene oxide)-poly(ethylene oxide) block copolymer (PEO-PPO-PEO) is a thermosensitive amphiphilic material, widely used in medical field. Herein, we replaced PEO with PEO-PPO-PEO to introduce temperature-sensitivity into adhesives, and utilized the hydrophilic-to-hydrophobic transition of PEO-PPO-PEO to reduce the swelling at human temperature. Fortunately, we got positive results that all the synthetized adhesives showed obvious temperature-sensitivity. The transition from low temperature to room temperature of the high concentrated uncured adhesive dispersion made it potentially injectable. After crosslinking, the swelling ratio of cured adhesives showed a significant decrease from 4°C to 37°C. And all the swelling ratios under 37°C were low, ranging from 8.4% to 22.5%. Additionally, the lap-shear adhesion strength on wet porcine skin was in the range of 29.2–67.1 kPa, which was higher than that of commercial fibrin glue (9–15 kPa). By selecting different (PEO)y(PPO)x(PEO)y, we could obtain adhesives with wide mechanical properties and broaden the scope of use of the adhesives.
{"title":"Temperature-sensitive mussel-inspired citrate-based tissue adhesives with low-swelling","authors":"Yiwen Xu, Yali Ji, Jinghong Ma","doi":"10.1080/00218464.2022.2097077","DOIUrl":"https://doi.org/10.1080/00218464.2022.2097077","url":null,"abstract":"ABSTRACT Mussel-inspired tissue adhesives have been widely studied in recent years because of their excellent underwater adhesion. Our recent study has synthesized a series of tissue adhesives with citric acid, dopamine, 1,8-octanediol and poly(ethylene oxide) (PEO), and found that amphiphilic adhesives showed an efficient underwater adhesion mechanism. Poly(propylene oxide)-poly(ethylene oxide) block copolymer (PEO-PPO-PEO) is a thermosensitive amphiphilic material, widely used in medical field. Herein, we replaced PEO with PEO-PPO-PEO to introduce temperature-sensitivity into adhesives, and utilized the hydrophilic-to-hydrophobic transition of PEO-PPO-PEO to reduce the swelling at human temperature. Fortunately, we got positive results that all the synthetized adhesives showed obvious temperature-sensitivity. The transition from low temperature to room temperature of the high concentrated uncured adhesive dispersion made it potentially injectable. After crosslinking, the swelling ratio of cured adhesives showed a significant decrease from 4°C to 37°C. And all the swelling ratios under 37°C were low, ranging from 8.4% to 22.5%. Additionally, the lap-shear adhesion strength on wet porcine skin was in the range of 29.2–67.1 kPa, which was higher than that of commercial fibrin glue (9–15 kPa). By selecting different (PEO)y(PPO)x(PEO)y, we could obtain adhesives with wide mechanical properties and broaden the scope of use of the adhesives.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43160538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-03DOI: 10.1080/00218464.2022.2095262
M. Ghasemvand, B. Behjat, Shabnam Ebrahimi
ABSTRACT In this article, the creep behavior and strength of single-lap adhesive joints ( s) including defects have been studied, and the effect of the position of defects on the creep behavior and strength of s have been investigated. The defects were created on various sides of the Araldite 2011 adhesive layer and joints were subjected to the tensile and creep tests. The creep tests were done at three different temperatures; 23 ℃ (Room Temperature), 45 ℃, and 55 ℃. The results showed that the presence of a defect in the adhesive layer caused the greatest decrease in the strength of the joints in the defective joint with the defect in the middle and both sides. Also, the presence of a defect in the adhesive layer increases the creep displacement, which is much higher than the amount of this displacement in the joint without a defect. Increasing temperature to 45 ℃, and 55 ℃ has increased the creep displacement by almost 90%, compared to the creep displacement at room temperature (RT). Based on the results, the presence of defects on both sides has the greatest effect on reducing the strength of the joint (defect in the middle) and increasing the creep displacement (defect in the edge).
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