Pub Date : 2021-06-02DOI: 10.1002/9781119846703.CH19
H. Baniya, R. P. Guragain, D. Subedi
This review summarizes the results of cold atmospheric pressure plasma technology application in polymers surface treatment. Attention is given to results of changes in the hydrophilic property of polymer surfaces by incorporation of polar functional groups when exposed to atmospheric pressure plasma, depending on the time of treatment, applied voltage, gas flow rate, and distance from the surface. We have successfully developed a plasma device that is able to generate cold atmospheric pressure argon plasma of low temperature (20 – 26) ° C downstream using a high-voltage power source which can be widely used in materials processing. Therefore, a cost-effective system of generating a plasma jet at atmospheric pressure with potential applications has been developed. Cold atmospheric pressure plasma jet (CAPPJ) has shown a lot of applications in recent years such as in materials processing, surface modification, and biomedical materials processing. CAPPJ has been generated by a high voltage (0-20 kV) and high frequency (20-30 kHz) power supply. The discharge has been characterized by optical and electrical methods. In order to characterize cold atmospheric pressure argon plasma jet, its electron density, electron temperature, rotational temperature, and vibration temperature have been determined using the power balance method, intensity ratio method, Stark broadening method, and Boltzmann plot method, respectively. The improvement in hydrophilicity of the cold plasma-treated polymer samples was characterized by contact angle measurements, surface free energy analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Contact angle analysis showed that the discharge was effective in improving the wettability of polymers after the treatment. Furthermore, atmospheric plasma can be effectively used to remove surface contamination and to chemically modify different polymer surfaces. The chemical changes, especially oxidation and cross-linking, enhance the surface properties of the polymers.
{"title":"Cold Atmospheric Pressure Plasma Technology for Modifying Polymers to Enhance Adhesion: A Critical Review","authors":"H. Baniya, R. P. Guragain, D. Subedi","doi":"10.1002/9781119846703.CH19","DOIUrl":"https://doi.org/10.1002/9781119846703.CH19","url":null,"abstract":"This review summarizes the results of cold atmospheric pressure plasma technology application in polymers surface treatment. Attention is given to results of changes in the hydrophilic property of polymer surfaces by incorporation of polar functional groups when exposed to atmospheric\u0000 pressure plasma, depending on the time of treatment, applied voltage, gas flow rate, and distance from the surface. We have successfully developed a plasma device that is able to generate cold atmospheric pressure argon plasma of low temperature (20 – 26) ° C downstream using a high-voltage\u0000 power source which can be widely used in materials processing. Therefore, a cost-effective system of generating a plasma jet at atmospheric pressure with potential applications has been developed. Cold atmospheric pressure plasma jet (CAPPJ) has shown a lot of applications in recent years\u0000 such as in materials processing, surface modification, and biomedical materials processing. CAPPJ has been generated by a high voltage (0-20 kV) and high frequency (20-30 kHz) power supply. The discharge has been characterized by optical and electrical methods. In order to characterize\u0000 cold atmospheric pressure argon plasma jet, its electron density, electron temperature, rotational temperature, and vibration temperature have been determined using the power balance method, intensity ratio method, Stark broadening method, and Boltzmann plot method, respectively. The improvement\u0000 in hydrophilicity of the cold plasma-treated polymer samples was characterized by contact angle measurements, surface free energy analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Contact angle analysis showed that the discharge was effective\u0000 in improving the wettability of polymers after the treatment. Furthermore, atmospheric plasma can be effectively used to remove surface contamination and to chemically modify different polymer surfaces. The chemical changes, especially oxidation and cross-linking, enhance the surface properties\u0000 of the polymers.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/9781119846703.CH19","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49654033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-02DOI: 10.1002/9781119846703.CH18
M. Dunky
Various naturally-based chemicals can be used directly as wood adhesives or are precursors for the synthesis of adhesive resins. Liquefaction and pyrolysis of wood yield various smaller chemicals derived from the different wood components, which then are used in the preparation of adhesives by replacing mainly phenol as raw material. The possible replacement of formaldehyde in aminoplastic and phenolic resins would solve the question of the subsequent formaldehyde emission. The multiple unsaturations of the triglycerides in vegetable oils enable polymerization for the direct synthesis of thermosets, as well as bases for polyfunctionalization and crosslinking. Natural polymers, such as poly(lactic acid)s (PLAs), natural rubber, or poly(hyhydroxyalkanoate)s (PHAs) are thermoplastics and can be used for various special applications in wood bonding, in case they can also be crosslinked. For other thermoplastic wood adhesives, such as PUR or PA, chemicals based on natural resources can at least replace a part or even all synthetic raw materials (monomers); these monomers derive from targeted decomposition of the wood material in biorefineries. Cellulose nanofibrils (CNFs) can be used as as sole adhesives or as components of adhesives. Hydrogen bonding has a key function in binder applications related to adhesion between cellulose nanoparticles and other materials. CNFs are able to establish strong bonding between wood particles/fibres through flexible and strong films by a simple drying process. Cashew nut shell liquid (CNSL) is a by-product of the cashew nut processing with cardanol (CD) as main component. CD-formaldehyde resins show improved flexibility compared to phenol-formaldehyde (PF) resins; CD can replace up to 40% of the phenol.
{"title":"Wood Adhesives Based on Natural Resources: A Critical Review: Part IV. Special Topics","authors":"M. Dunky","doi":"10.1002/9781119846703.CH18","DOIUrl":"https://doi.org/10.1002/9781119846703.CH18","url":null,"abstract":"Various naturally-based chemicals can be used directly as wood adhesives or are precursors for the synthesis of adhesive resins. Liquefaction and pyrolysis of wood yield various smaller chemicals derived from the different wood components, which then are used in the preparation of adhesives\u0000 by replacing mainly phenol as raw material. The possible replacement of formaldehyde in aminoplastic and phenolic resins would solve the question of the subsequent formaldehyde emission. The multiple unsaturations of the triglycerides in vegetable oils enable polymerization for\u0000 the direct synthesis of thermosets, as well as bases for polyfunctionalization and crosslinking. Natural polymers, such as poly(lactic acid)s (PLAs), natural rubber, or poly(hyhydroxyalkanoate)s (PHAs) are thermoplastics and can be used for various special applications in wood bonding,\u0000 in case they can also be crosslinked. For other thermoplastic wood adhesives, such as PUR or PA, chemicals based on natural resources can at least replace a part or even all synthetic raw materials (monomers); these monomers derive from targeted decomposition of the wood material in biorefineries.\u0000 Cellulose nanofibrils (CNFs) can be used as as sole adhesives or as components of adhesives. Hydrogen bonding has a key function in binder applications related to adhesion between cellulose nanoparticles and other materials. CNFs are able to establish strong bonding between wood particles/fibres\u0000 through flexible and strong films by a simple drying process. Cashew nut shell liquid (CNSL) is a by-product of the cashew nut processing with cardanol (CD) as main component. CD-formaldehyde resins show improved flexibility compared to phenol-formaldehyde (PF) resins; CD can replace\u0000 up to 40% of the phenol.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/9781119846703.CH18","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41400528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent progress in the adhesion mechanism of mussels has led to great excitement in the field of adhesive materials. Although great progress has been made in the mussel adhesion mechanism and underwater adhesives, there are still many unknowns and challenges in this area. Thus, it is highly important to review the recent progress in mechanisms of mussel adhesion and mussel-inspired adhesives and predict trends for the future. In this review, we (1) summarize the research progress in fundamental interaction mechanisms in natural mussels; (2) discuss the application of the mussel interaction mechanism in the biomimetic mussel adhesive materials, from permanent/high-strength adhesives to temporary/smart adhesives; (3) briefly state the potential applications of the mussel-inspired adhesives in multiple fields, such as engineering applications, smart robotics and biomedicine; (4) summarize the future perspectives and unsolved challenges of mussel adhesion mechanisms and mussel-inspired adhesive materials. We envision that this review will provide an insightful perspective in understanding the mussel adhesion mechanism and directions to further explore, and promote the development of novel biomimetic mussel adhesive materials.
{"title":"Mussel-Inspired Underwater Adhesives- from Adhesion Mechanisms to Engineering Applications: A Critical Review","authors":"Yanfei Ma, Bozhen Zhang, Imri Frenkel, Zhizhi Zhang, Xiaowei Pei, Zhou Feng, Ximin He","doi":"10.1002/9781119846703.CH17","DOIUrl":"https://doi.org/10.1002/9781119846703.CH17","url":null,"abstract":"Recent progress in the adhesion mechanism of mussels has led to great excitement in the field of adhesive materials. Although great progress has been made in the mussel adhesion mechanism and underwater adhesives, there are still many unknowns and challenges in this area. Thus, it is\u0000 highly important to review the recent progress in mechanisms of mussel adhesion and mussel-inspired adhesives and predict trends for the future. In this review, we (1) summarize the research progress in fundamental interaction mechanisms in natural mussels; (2) discuss the application of the\u0000 mussel interaction mechanism in the biomimetic mussel adhesive materials, from permanent/high-strength adhesives to temporary/smart adhesives; (3) briefly state the potential applications of the mussel-inspired adhesives in multiple fields, such as engineering applications, smart robotics\u0000 and biomedicine; (4) summarize the future perspectives and unsolved challenges of mussel adhesion mechanisms and mussel-inspired adhesive materials. We envision that this review will provide an insightful perspective in understanding the mussel adhesion mechanism and directions to further\u0000 explore, and promote the development of novel biomimetic mussel adhesive materials.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/9781119846703.CH17","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42266568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This series of critical reviews on Wood Adhesives Based on Natural Resources (in total four parts) describes the experience and actual status of wood adhesives based on natural resources and gives an outlook into the future of these materials. Desite boundless results and papers in the development, purely naturally based wood adhesives are in industrial use only in negligible amounts; therefore this review series also reports on combinations of naturally based adhesives with synthetic components, such as modifiers or crosslinkers. Part I of this series concentrates on general topics and questions related to wood adhesives based on natural resources, such as systematic overview on the various types of naturally based wood adhesives, including cases where the adhesive is not applied separately but is used in situ, originating from the various components of the wood material. As a first product group, proteins from plants and animal sources and their use as wood adhesives will be described in this Part I.
{"title":"Wood Adhesives Based on Natural Resources: A Critical Review Part I. Protein-Based Adhesives","authors":"M. Dunky","doi":"10.7569/raa.2020.097309","DOIUrl":"https://doi.org/10.7569/raa.2020.097309","url":null,"abstract":"This series of critical reviews on Wood Adhesives Based on Natural Resources (in total four parts) describes the experience and actual status of wood adhesives based on natural resources and gives an outlook into the future of these materials. Desite boundless results and papers in\u0000 the development, purely naturally based wood adhesives are in industrial use only in negligible amounts; therefore this review series also reports on combinations of naturally based adhesives with synthetic components, such as modifiers or crosslinkers. Part I of this series concentrates\u0000 on general topics and questions related to wood adhesives based on natural resources, such as systematic overview on the various types of naturally based wood adhesives, including cases where the adhesive is not applied separately but is used in situ, originating from the various components\u0000 of the wood material. As a first product group, proteins from plants and animal sources and their use as wood adhesives will be described in this Part I.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46571484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The necessity for a long time contact between the drug and mucus layer/epithelial cell or a combination of the two requires a bioadhesive. A bioadhesive is known to intensify contact between the two and help in controlled release of drugs. The conventionally used bioadhesives are known to have poor adhesion strength and can have toxic side effects. This review focuses on the various types of polymers and their composites for use as bioadhesives which can overcome the previously mentioned issues. These include some naturally occurring bioadhesives such as collagen, chitosan, albumin, dextran and some synthetic bioadhesives like gelatin, poly(ethylene glycol), poly(acrylic acid), poly(lactic-co-glycolic acid) based bioadhesives. The clinical trials prove the effectiveness of these bioadhesives and they are found to be more efficient than the commercial glues and hence possess great potential for use in the biomedical industry.
{"title":"Bioadhesives in Biomedical Applications: A Critical Review","authors":"A. Dey, Proma Bhattacharya, S. Neogi","doi":"10.7569/raa.2020.097308","DOIUrl":"https://doi.org/10.7569/raa.2020.097308","url":null,"abstract":"The necessity for a long time contact between the drug and mucus layer/epithelial cell or a combination of the two requires a bioadhesive. A bioadhesive is known to intensify contact between the two and help in controlled release of drugs. The conventionally used bioadhesives are known\u0000 to have poor adhesion strength and can have toxic side effects. This review focuses on the various types of polymers and their composites for use as bioadhesives which can overcome the previously mentioned issues. These include some naturally occurring bioadhesives such as collagen, chitosan,\u0000 albumin, dextran and some synthetic bioadhesives like gelatin, poly(ethylene glycol), poly(acrylic acid), poly(lactic-co-glycolic acid) based bioadhesives. The clinical trials prove the effectiveness of these bioadhesives and they are found to be more efficient than the commercial glues and\u0000 hence possess great potential for use in the biomedical industry.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44635230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Singh, G. Devi, B. Barik, Ankita Sharma, Loveleen Kaur
Pellets are spherical shaped multiparticulate drug delivery systems with size ranging between 0.5-2.0 mm. Free flow, good mechanical properties, improved physical and chemical properties of powder, and stability are some advantages of pellets. Mucoadhesive pellets could be developed by using appropriate concentration and type of mucoadhesive polymer. Mucoadhesive pellets can be used for delivery of drugs to gastric, colonic, and vaginal regions. Immediate release, sustained/controlled release and implantable delivery could be incorporated using mucoadhesive pellets. Reproducibility, ease of scalability, quality control checks and significant mechanical strength are some advantages making pellets widely acceptable by pharmaceutical industry. In the present review, mucoadhesion process and theories, mucoadhesive polymers, pelletization process, evaluation of pellets and reported research/patents on mucoadhesive pellets for delivery of different categories of drugs have been presented.
{"title":"Mucoadhesive Pellets for Drug Delivery Applications: A Critical Review","authors":"I. Singh, G. Devi, B. Barik, Ankita Sharma, Loveleen Kaur","doi":"10.7569/raa.2020.097305","DOIUrl":"https://doi.org/10.7569/raa.2020.097305","url":null,"abstract":"Pellets are spherical shaped multiparticulate drug delivery systems with size ranging between 0.5-2.0 mm. Free flow, good mechanical properties, improved physical and chemical properties of powder, and stability are some advantages of pellets. Mucoadhesive pellets could be developed\u0000 by using appropriate concentration and type of mucoadhesive polymer. Mucoadhesive pellets can be used for delivery of drugs to gastric, colonic, and vaginal regions. Immediate release, sustained/controlled release and implantable delivery could be incorporated using mucoadhesive pellets. Reproducibility,\u0000 ease of scalability, quality control checks and significant mechanical strength are some advantages making pellets widely acceptable by pharmaceutical industry. In the present review, mucoadhesion process and theories, mucoadhesive polymers, pelletization process, evaluation of pellets and\u0000 reported research/patents on mucoadhesive pellets for delivery of different categories of drugs have been presented.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46376106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the increasing discussion about sustainable and CO2-reduced materials, the demand for cellulose-based fibres as a reinforcing component in thermoplastic composites has increased considerably. Knowledge about the possibilities of modifying fibres for improved adhesion to the plastic matrix is essential in this context. The fibre/matrix adhesion in cellulose fibre-reinforced polymers is of considerable importance for the design of composite materials. Unfortunately, there are no standards for many essential methods to determine fibre/matrix adhesion. In this review article, various methods for measuring the interfacial shear strength between fibres and matrix, as an indirect characterisation of adhesion, are presented. Additionally, a brief overview of different methods for surface modification of cellulose fibres to improve the adhesion to a thermoplastic matrix is given. This review focuses on the fact that the parameters for the production of test specimens as well as the test method itself can vary considerably from study to study. Because of this, the comparison of data from different publications is not always possible. Therefore, in this article, the main influencing factors and differences in the methods are presented and discussed. Based on a systematic review and a clear description and discussion of the methods, the reader is given a broad basis for a better understanding of characteristic values for fibre/matrix adhesion.
{"title":"Test Methods for Fibre/Matrix Adhesion in Cellulose Fibre-Reinforced Thermoplastic Composite Materials: A Critical Review","authors":"J. Müssig, N. Graupner","doi":"10.7569/raa.2020.097306","DOIUrl":"https://doi.org/10.7569/raa.2020.097306","url":null,"abstract":"Due to the increasing discussion about sustainable and CO2-reduced materials, the demand for cellulose-based fibres as a reinforcing component in thermoplastic composites has increased considerably. Knowledge about the possibilities of modifying fibres for improved adhesion\u0000 to the plastic matrix is essential in this context. The fibre/matrix adhesion in cellulose fibre-reinforced polymers is of considerable importance for the design of composite materials. Unfortunately, there are no standards for many essential methods to determine fibre/matrix adhesion. In\u0000 this review article, various methods for measuring the interfacial shear strength between fibres and matrix, as an indirect characterisation of adhesion, are presented. Additionally, a brief overview of different methods for surface modification of cellulose fibres to improve the adhesion\u0000 to a thermoplastic matrix is given. This review focuses on the fact that the parameters for the production of test specimens as well as the test method itself can vary considerably from study to study. Because of this, the comparison of data from different publications is not always possible.\u0000 Therefore, in this article, the main influencing factors and differences in the methods are presented and discussed. Based on a systematic review and a clear description and discussion of the methods, the reader is given a broad basis for a better understanding of characteristic values for\u0000 fibre/matrix adhesion.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.7569/raa.2020.097306","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48054021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The existence of contact angle hysteresis – the difference between the values of the advancing and receding contact angles – is evident in nature (e.g. sticking of rain drops to car windscreens and window panes) and many industrial processes (e.g. surface coating, spraying, and dyeing of fabrics). This phenomenon is often viewed as a nuisance, but it is advantageous in many processes including dip and spin coating, spraying, and painting. With the early theoretical framework of Thomas Young, Robert Wenzel, and A. B. D. Cassie and S. Baxter, describing the wettability of solid surfaces and by extension contact angle, contact angle hysteresis has been deeply investigated. We review here the various ways of measuring contact angle and, consequently, contact angle hysteresis as well as related theoretical models. The successes and limitations of these models are highlighted. We conclude with the advantages and disadvantages of contact angle hysteresis whose presence in many processes is often considered as a nuisance, especially when "coffee stain" forms from the evaporation of a volatile liquid drop containing nonvolatile components.
{"title":"Contact Angle Hysteresis – Advantages and Disadvantages: A Critical Review","authors":"A. T. Tyowua, Stephen Gbaoron Yiase","doi":"10.7569/raa.2020.097302","DOIUrl":"https://doi.org/10.7569/raa.2020.097302","url":null,"abstract":"The existence of contact angle hysteresis – the difference between the values of the advancing and receding contact angles – is evident in nature (e.g. sticking of rain drops to car windscreens and window panes) and many industrial processes (e.g. surface coating,\u0000 spraying, and dyeing of fabrics). This phenomenon is often viewed as a nuisance, but it is advantageous in many processes including dip and spin coating, spraying, and painting. With the early theoretical framework of Thomas Young, Robert Wenzel, and A. B. D. Cassie and S. Baxter, describing\u0000 the wettability of solid surfaces and by extension contact angle, contact angle hysteresis has been deeply investigated. We review here the various ways of measuring contact angle and, consequently, contact angle hysteresis as well as related theoretical models. The successes and limitations\u0000 of these models are highlighted. We conclude with the advantages and disadvantages of contact angle hysteresis whose presence in many processes is often considered as a nuisance, especially when \"coffee stain\" forms from the evaporation of a volatile liquid drop containing nonvolatile components.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43981970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hot-Melt Adhesives (HMAs) are typically used in applications where instant sealing is critically required. HMAs are generally preferred for those applications where processing speed is critical. These materials are widely used in various engineering applications, mainly as sealants in leakages and crack filling of walls and roofs. The industrial use of HMAs is most common in glassware and automobiles for gluing glasses in buildings and bonding heavy motor parts. The formulation of HMAs contains a polymer of suitable nature that makes the base for a strong adhesive, and waxes are added to increase the settling time of adhesive. The tackifiers are used to dilute the polymer to adjust the Glass Transition Temperature (Tg) and to reduce the viscosity for proper flow of hot-melt. This review intends to comprehensively discuss the preparation and formulations of HMAs using various polymer matrices, along with their applications and mechanics. The designing of green HMAs has been discussed in the literature and have been promoted over conventional solvent-based HMAs due to their functionality without Volatile Organic Compounds (VOCs). Various measures, challenges, and resolutions for making hazard-free HMAs have been discussed in the present review.
{"title":"Hot-Melt Adhesives: Fundamentals, Formulations, and Applications: A Critical Review","authors":"Swaroop Gharde, G. Sharma, B. Kandasubramanian","doi":"10.7569/raa.2020.097301","DOIUrl":"https://doi.org/10.7569/raa.2020.097301","url":null,"abstract":"Hot-Melt Adhesives (HMAs) are typically used in applications where instant sealing is critically required. HMAs are generally preferred for those applications where processing speed is critical. These materials are widely used in various engineering applications, mainly as sealants\u0000 in leakages and crack filling of walls and roofs. The industrial use of HMAs is most common in glassware and automobiles for gluing glasses in buildings and bonding heavy motor parts. The formulation of HMAs contains a polymer of suitable nature that makes the base for a strong adhesive, and\u0000 waxes are added to increase the settling time of adhesive. The tackifiers are used to dilute the polymer to adjust the Glass Transition Temperature (Tg) and to reduce the viscosity for proper flow of hot-melt. This review intends to comprehensively discuss the preparation and formulations\u0000 of HMAs using various polymer matrices, along with their applications and mechanics. The designing of green HMAs has been discussed in the literature and have been promoted over conventional solvent-based HMAs due to their functionality without Volatile Organic Compounds (VOCs). Various measures,\u0000 challenges, and resolutions for making hazard-free HMAs have been discussed in the present review.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43248630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A review on optimization of adhesively bonded spar-wingskin joint (SWJ) of laminated fiber reinforced polymer (FRP) composites subjected to pull-off load is presented in this article using three-dimensional finite element analysis. Von Mises stress components have been computed across the width of joint at different interfaces viz. load coupler-spar, and load coupler-wingskin interfaces. Further, the weight of SWJ structure is considered as the objective function which needs to be minimized for optimization. In the first step, the material and lamination scheme of the FRP composite materials used for SWJ are optimized, and, in the second step, the geometrical parameters have been optimized on the basis of minimum von Mises stress and weight. Further, the effects of the material, lamination scheme, and geometrical parameters on the von Mises stress and weight have been validated using the Analysis of Variance (ANOVA) approach as prescribed by the Taguchi method. The results show that the material and spar thickness are the most significant factors influencing von Mises stress. The weight analysis reveals that there is a significant effect of change in material and wingskin thickness on SWJ performance. Suitable design recommendations have been made for SWJ in terms of material, lamination scheme and geometrical parameters.
{"title":"Optimization of Adhesively Bonded Spar-Wingskin Joints of Laminated FRP Composites Subjected to Pull-Off Load: A Critical Review","authors":"S. Rakshe, S. Nimje, S. K. Panigrahi","doi":"10.7569/raa.2020.097303","DOIUrl":"https://doi.org/10.7569/raa.2020.097303","url":null,"abstract":"A review on optimization of adhesively bonded spar-wingskin joint (SWJ) of laminated fiber reinforced polymer (FRP) composites subjected to pull-off load is presented in this article using three-dimensional finite element analysis. Von Mises stress components have been computed across\u0000 the width of joint at different interfaces viz. load coupler-spar, and load coupler-wingskin interfaces. Further, the weight of SWJ structure is considered as the objective function which needs to be minimized for optimization. In the first step, the material and lamination scheme of the FRP\u0000 composite materials used for SWJ are optimized, and, in the second step, the geometrical parameters have been optimized on the basis of minimum von Mises stress and weight. Further, the effects of the material, lamination scheme, and geometrical parameters on the von Mises stress and weight\u0000 have been validated using the Analysis of Variance (ANOVA) approach as prescribed by the Taguchi method. The results show that the material and spar thickness are the most significant factors influencing von Mises stress. The weight analysis reveals that there is a significant effect of change\u0000 in material and wingskin thickness on SWJ performance. Suitable design recommendations have been made for SWJ in terms of material, lamination scheme and geometrical parameters.","PeriodicalId":43792,"journal":{"name":"Reviews of Adhesion and Adhesives","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45856806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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