Application of Atmospheric Pressure Plasma in Polymer and Composite Adhesion

Application of Atmospheric Pressure Plasma in Polymer and Composite Adhesion PDF Author: Hang Yu
Publisher:
ISBN:
Category :
Languages : en
Pages : 198

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Book Description
An atmospheric pressure helium and oxygen plasma was used to investigate surface activation and bonding in polymer composites. This device was operated by passing 1.0-3.0 vol% of oxygen in helium through a pair of parallel plate metal electrodes powered by 13.56 or 27.12 MHz radio frequency power. The gases were partially ionized between the capacitors where plasma was generated. The reactive species in the plasma were carried downstream by the gas flow to treat the substrate surface. The temperature of the plasm gas reaching the surface of the substrate did not exceed 150 oC, which makes it suitable for polymer processing. The reactive species in the plasma downstream includes ~ 1016-1017 cm-3 atomic oxygen, ~ 1015 cm-3 ozone molecule, and ~ 1016 cm-3 metastable oxygen molecule (O21 g). The substrates were treated at 2-5 mm distance from the exit of the plasma. Surface properties of the substrates were characterized using water contact angle (WCA), atomic force microscopy (AFM), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). Subsequently, the plasma treated samples were bonded adhesively or fabricated into composites. The increase in mechanical strength was correlated to changes in the material composition and structure after plasma treatment. The work presented hereafter establishes atmospheric pressure plasma as an effective method to activate and to clean the surfaces of polymers and composites for bonding. This application can be further expanded to the activation of carbon fibers for better fiber-resin interactions during the fabrication of composites. Treating electronic grade FR-4 and polyimide with the He/O2 plasma for a few seconds changed the substrate surface from hydrophobic to hydrophilic, which allowed complete wetting of the surface by epoxy in underfill applications. Characterization of the surface by X-ray photoelectron spectroscopy shows formation of oxygenated functional groups, including hydroxyl, carbonyl, and carboxyl groups, on the polymer surface after plasma treatment. The resulting strength of the bond based on lap-shear and T-peel tests correlates well with the concentration of oxygen on the polymer surface. The failure modes observed for lap-shear and T-peel tests changed from interfacial to cohesive after the plasma activation. Treating carbon-fiber-reinforced epoxy composites with the atmospheric plasma resulted in the removal of fluorinated contaminants in shallow surface layers. For contaminants that diffused deeply into the composite surface, mechanical abrasion was needed in addition to the plasma treatment to remove the impurities. While cleaning the composite, plasma also generated active oxygen groups on the substrate surface. The presence of these groups improved the adhesive bonding strength of the composite even in the presence of residual fluorine contaminants. Thus, it was speculated that plasma treatment can promote better polymer adhesion with or without fluorine contamination. Carbon nanotube sheets were also treated by the helium oxygen plasma, and the CNT surface turn from super hydrophobic to hydrophilic after a few seconds of exposure. The nanotube surface contained 15 % of oxygen in the form of hydroxyl groups. Chemical coupling agents were added to the plasma activated CNT surfaces in order to crosslink the CNTs and to create bonding sites for the resin matrix. Stretched, activated and functionalized CNT was cured with dicyclopentadiene (DCPD) to produce a sheet composite with a tensile strength of 636 MPa, a modulus of 28 GPa, and a density of 1.4 g/cm3. This may be compared to aerospace-grade aluminum with tensile strength of 572 MPa, modulus of 72 GPa, and density of 2.7 g/cm3. This work demonstrates that new high-strength composite can be produced with the use of atmospheric plasma activation and chemical crosslinking of the fiber matrix.

Application of Atmospheric Pressure Plasma in Polymer and Composite Adhesion

Application of Atmospheric Pressure Plasma in Polymer and Composite Adhesion PDF Author: Hang Yu
Publisher:
ISBN:
Category :
Languages : en
Pages : 198

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Book Description
An atmospheric pressure helium and oxygen plasma was used to investigate surface activation and bonding in polymer composites. This device was operated by passing 1.0-3.0 vol% of oxygen in helium through a pair of parallel plate metal electrodes powered by 13.56 or 27.12 MHz radio frequency power. The gases were partially ionized between the capacitors where plasma was generated. The reactive species in the plasma were carried downstream by the gas flow to treat the substrate surface. The temperature of the plasm gas reaching the surface of the substrate did not exceed 150 oC, which makes it suitable for polymer processing. The reactive species in the plasma downstream includes ~ 1016-1017 cm-3 atomic oxygen, ~ 1015 cm-3 ozone molecule, and ~ 1016 cm-3 metastable oxygen molecule (O21 g). The substrates were treated at 2-5 mm distance from the exit of the plasma. Surface properties of the substrates were characterized using water contact angle (WCA), atomic force microscopy (AFM), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). Subsequently, the plasma treated samples were bonded adhesively or fabricated into composites. The increase in mechanical strength was correlated to changes in the material composition and structure after plasma treatment. The work presented hereafter establishes atmospheric pressure plasma as an effective method to activate and to clean the surfaces of polymers and composites for bonding. This application can be further expanded to the activation of carbon fibers for better fiber-resin interactions during the fabrication of composites. Treating electronic grade FR-4 and polyimide with the He/O2 plasma for a few seconds changed the substrate surface from hydrophobic to hydrophilic, which allowed complete wetting of the surface by epoxy in underfill applications. Characterization of the surface by X-ray photoelectron spectroscopy shows formation of oxygenated functional groups, including hydroxyl, carbonyl, and carboxyl groups, on the polymer surface after plasma treatment. The resulting strength of the bond based on lap-shear and T-peel tests correlates well with the concentration of oxygen on the polymer surface. The failure modes observed for lap-shear and T-peel tests changed from interfacial to cohesive after the plasma activation. Treating carbon-fiber-reinforced epoxy composites with the atmospheric plasma resulted in the removal of fluorinated contaminants in shallow surface layers. For contaminants that diffused deeply into the composite surface, mechanical abrasion was needed in addition to the plasma treatment to remove the impurities. While cleaning the composite, plasma also generated active oxygen groups on the substrate surface. The presence of these groups improved the adhesive bonding strength of the composite even in the presence of residual fluorine contaminants. Thus, it was speculated that plasma treatment can promote better polymer adhesion with or without fluorine contamination. Carbon nanotube sheets were also treated by the helium oxygen plasma, and the CNT surface turn from super hydrophobic to hydrophilic after a few seconds of exposure. The nanotube surface contained 15 % of oxygen in the form of hydroxyl groups. Chemical coupling agents were added to the plasma activated CNT surfaces in order to crosslink the CNTs and to create bonding sites for the resin matrix. Stretched, activated and functionalized CNT was cured with dicyclopentadiene (DCPD) to produce a sheet composite with a tensile strength of 636 MPa, a modulus of 28 GPa, and a density of 1.4 g/cm3. This may be compared to aerospace-grade aluminum with tensile strength of 572 MPa, modulus of 72 GPa, and density of 2.7 g/cm3. This work demonstrates that new high-strength composite can be produced with the use of atmospheric plasma activation and chemical crosslinking of the fiber matrix.

Atmospheric Pressure Plasma Treatment of Polymers

Atmospheric Pressure Plasma Treatment of Polymers PDF Author: Michael Thomas
Publisher: John Wiley & Sons
ISBN: 1118596218
Category : Technology & Engineering
Languages : en
Pages : 0

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Book Description
An indispensable volume detailing the current and potential applications of atmospheric pressure plasma treatment by experts practicing in fields around the world Polymers are used in a wide variety of industries to fabricate legions of products because of their many desirable traits. However, polymers in general (and polyolefins, in particular) are innately not very adhesionable because of the absence of polar or reactive groups on their surfaces and concomitant low surface energy. Surface treatment of polymers, however, is essential to impart reactive chemical groups on their surfaces to enhance their adhesion characteristic. Proper surface treatment can endow polymers with improved adhesion without affecting the bulk properties. A plethora of techniques (ranging from wet to dry, simple to sophisticated, vacuum to non-vacuum) for polymer surface modification have been documented in the literature but the Atmospheric Pressure Plasma (APP) treatment has attracted much attention because it offers many advantages vis-a-vis other techniques, namely uniform treatment, continuous operation, no need for vacuum, simplicity, low cost, no environmental or disposal concern, and applicability to large area samples. Although the emphasis in this book is on the utility of APP treatment for enhancement of polymer adhesion, APP is also applicable and effective to modulate many other surface properties of polymers: superhydrophilicity, superhydrophobicity, anti-fouling, anti-fogging, anti-icing, cell adhesion, biocompatibility, tribological behavior, etc. The key features of Atmospheric Pressure Plasma Treatment of Polymers: Address design and functions of various types of reactors Bring out current and potential applications of APP treatment Represent the cumulative wisdom of many key academic and industry researchers actively engaged in this key and enabling technology

Atmospheric Pressure Plasma Deposition of Thin Organic Films for Improved Adhesion in Polymer Composites

Atmospheric Pressure Plasma Deposition of Thin Organic Films for Improved Adhesion in Polymer Composites PDF Author: Dominic Weeber
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
"Composite polymers in the form of multilayer laminates are used to produce multifunctional surfaces such as food packaging, pool linings, or automotive interiors. Individual sheets provide antimicrobial properties, water resistance, or mechanical properties and require a sound union for robust composite performance. Current industrial processes use toxic isocyanate containing adhesives to bind the multiple layers together, which could be replaced with plasma deposition of nitrogen-rich organic adhesive coatings. Here, atmospheric-pressure dielectric barrier discharge (DBD) plasma is shown to enhance adhesion between a Thermoplastic Polyolefin (TPO) substrate and Polyurethane (PU) coating in an industrially suitable process. Sample production begins by treating TPO with two stages of DBD, operating at 18.7 kHz and 9.9 kVpp. Initial plasma treatment within a simulated air mixture achieves surface activation of TPO through oxidative reactions. A nitrogen-rich organic film is then deposited in the form of a plasma polymer through further DBD treatment using a mixture of nitrogen and either ethylene or butadiene. XPS characterization of samples at this stage showed up to 25 at% Nitrogen incorporated in produced plasma polymers. Following plasma treatment of TPO, solvent based polyurethane is then twice brush coated onto the modified substrate and cured in an oven at 95 °C. Samples are finally assessed for the quality of adhesion between TPO and PU layers by qualitative and quantitative peel testing. Analysis of peel tests has shown clear improvements over samples without plasma polymer deposition, but lower delaminating loads than for samples produced with PECVD. Significant improvements including additional steps for quality control are required at lab scale to meet industrial standards. Nevertheless, the demonstrated adhesion enhancement, using an atmospheric pressure DBD plasma system, is a promising concept for polymer production. " --

Atmospheric Pressure Plasma Treatment of Polymers

Atmospheric Pressure Plasma Treatment of Polymers PDF Author: Michael Thomas
Publisher: John Wiley & Sons
ISBN: 1118747518
Category : Technology & Engineering
Languages : en
Pages : 435

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Book Description
An indispensable volume detailing the current and potential applications of atmospheric pressure plasma treatment by experts practicing in fields around the world Polymers are used in a wide variety of industries to fabricate legions of products because of their many desirable traits. However, polymers in general (and polyolefins, in particular) are innately not very adhesionable because of the absence of polar or reactive groups on their surfaces and concomitant low surface energy. Surface treatment of polymers, however, is essential to impart reactive chemical groups on their surfaces to enhance their adhesion characteristic. Proper surface treatment can endow polymers with improved adhesion without affecting the bulk properties. A plethora of techniques (ranging from wet to dry, simple to sophisticated, vacuum to non-vacuum) for polymer surface modification have been documented in the literature but the Atmospheric Pressure Plasma (APP) treatment has attracted much attention because it offers many advantages vis-a-vis other techniques, namely uniform treatment, continuous operation, no need for vacuum, simplicity, low cost, no environmental or disposal concern, and applicability to large area samples. Although the emphasis in this book is on the utility of APP treatment for enhancement of polymer adhesion, APP is also applicable and effective to modulate many other surface properties of polymers: superhydrophilicity, superhydrophobicity, anti-fouling, anti-fogging, anti-icing, cell adhesion, biocompatibility, tribological behavior, etc. The key features of Atmospheric Pressure Plasma Treatment of Polymers: Address design and functions of various types of reactors Bring out current and potential applications of APP treatment Represent the cumulative wisdom of many key academic and industry researchers actively engaged in this key and enabling technology

Progress in Adhesion and Adhesives, Volume 6

Progress in Adhesion and Adhesives, Volume 6 PDF Author: K. L. Mittal
Publisher: John Wiley & Sons
ISBN: 111984665X
Category : Technology & Engineering
Languages : en
Pages : 914

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Book Description
With the voluminous research being published, it is difficult, if not impossible, to stay abreast of current developments in a given area. The review articles in this book consolidate information to provide an alternative way to follow the latest research activity and developments in adhesion science and adhesives. With the ever-increasing amount of research being published, it is a Herculean task to be fully conversant with the latest research developments in any field, and the arena of adhesion and adhesives is no exception. Thus, topical review articles provide an alternate and very efficient way to stay abreast of the state-of-the-art in many subjects representing the field of adhesion science and adhesives. The 19 chapters in this Volume 6 follow the same order as the review articles originally published in RAA in the year 2020 and up to June 2021. The subjects of these 19 chapters fall in the following areas: Adhesives and adhesive joints Contact angle Reinforced polymer composites Bioadhesives Icephobic coatings Adhesives based on natural resources Polymer surface modification Superhydrophobic surfaces The topics covered include: hot-melt adhesives; adhesively-bonded spar-wingskin joints; contact angle hysteresis; fiber/matrix adhesion in reinforced thermoplastic composites; bioadhesives in biomedical applications; mucoadhesive pellets for drug delivery applications; bio-inspired icephobic coatings; wood adhesives based on natural resources; adhesion in biocomposites; vacuum UV surface photo-oxidation of polymers and other materials; vitrimers and their relevance to adhesives; superhydrophobic surfaces by microtexturing; structural acrylic adhesives; mechanically durable water-repellent surfaces; mussel-inspired underwater adhesives; and cold atmospheric pressure plasma technology for modifying polymers. Audience This book will be valuable and useful to researchers and technologists in materials science, nanotechnology, physics, surface and colloid chemistry in multiple disciplines in academia, industry, various research institutes and other organizations.

Effect of Atmospheric Pressure Plasma Treatment on Surface Characteristics and Adhesive Bond Quality of Peel Ply Prepared Composites

Effect of Atmospheric Pressure Plasma Treatment on Surface Characteristics and Adhesive Bond Quality of Peel Ply Prepared Composites PDF Author: Ashley C. Tracey
Publisher:
ISBN:
Category :
Languages : en
Pages : 174

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Book Description
The purpose of this research was to investigate if atmospheric pressure plasma treatment could modify peel ply prepared composite surfaces to create strong adhesive bonds. Two peel ply surface preparation composite systems previously shown to create weak bonds (low fracture energy and adhesion failure) that were potential candidates for plasma treatment were Toray T800/3900-2 carbon fiber reinforced polymer (CFRP) prepared with Precision Fabrics Group, Inc. (PFG) 52006 nylon peel ply and Hexcel T300/F155 CFRP prepared with PFG 60001 polyester peel ply. It was hypothesized that atmospheric pressure plasma treatment could functionalize and/or remove peel ply remnants left on the CFRP surfaces upon peel ply removal. Surface characterization measurements and double cantilever beam (DCB) testing were used to determine the effects of atmospheric pressure plasma treatment on surface characteristics and bond quality of peel ply prepared CFRP composites. Previous research showed that Toray T800/3900-2 carbon fiber reinforced epoxy composites prepared with PFG 52006 peel ply and bonded with Cytec MetlBond 1515-3M structural film adhesive failed in adhesion at low fracture energies when tested in the DCB configuration. Previous research also showed that DCB samples made of Hexcel T300/F155 carbon fiber reinforced epoxy composites prepared with PFG 60001 peel ply and bonded with Henkel Hysol EA 9696 structural film adhesive failed in adhesion at low fracture energies. Recent research suggested that plasma treatment could be able to activate these "un-bondable" surfaces and result in good adhesive bonds. Nylon peel ply prepared 177°C cure and polyester peel ply prepared 127 °C cure CFRP laminates were treated with atmospheric pressure plasma after peel ply removal prior to bonding. Atmospheric pressure plasma treatment was capable of significantly increasing fracture energies and changing failure modes. For Toray T800/3900-2 laminates prepared with PFG 52006 and bonded with MetlBond 1515-3M, plasma treatment increased fracture energies from 200 J/m2 to 460 J/m2. Atmospheric pressure plasma treatment also increased fracture energies of Hexcel T300/F155 laminates prepared with PFG 60001 and bonded with EA 9696 from 280 J/m2 to 1500 J/m2. It was demonstrated that atmospheric pressure plasma treatment was able to transform poor bonding surfaces into acceptable ones by reversing the negative effects of incorrect peel ply usage. To determine if the primary reason for adhesion was functionalization or removal, a number of experiments were performed. Surface characteristics of peel ply only and plasma treated samples were determined using contact angle (CA) measurements, FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). CA was used to assess solid surface energy that was useful to determine wetting of the adhesive on the adherend, one requirement of adhesion. FTIR and XPS were used to analyze composite surface chemistry, including the identification of functional groups that were a product of atmospheric pressure plasma treatment, as well as contaminants that can inhibit adhesive bonding. SEM was used to capture surface morphology to identify peel ply remnants and whether these remnants were physically removed or modified due to plasma treatment. This research supported that atmospheric pressure plasma treatment resulted in adhesion primarily due to functionalization of peel ply remnants, though a removal mechanism was not disproven. It was also shown that surface energy exhibited potential for predicting adhesion. Lastly, this research indicated that plasma treatment is a robust surface preparation, as strong bonds were observed up to 30 days after treatment.

Advanced Composites for Aerospace, Marine, and Land Applications

Advanced Composites for Aerospace, Marine, and Land Applications PDF Author: Tomoko Sano
Publisher: John Wiley & Sons
ISBN: 1118888537
Category : Technology & Engineering
Languages : en
Pages : 286

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Book Description
The papers in this volume cover a broad spectrum of topics that represent the truly diverse nature of the field of composite materials. This collection presents research and findings relevant to the latest advances in composites materials, specifically their use in aerospace, maritime, and even land applications. The editors have made every effort to bring together authors who put forth recent advances in their research while concurrently both elaborating on and thereby enhancing our prevailing understanding of the salient aspects related to the science, engineering, and far-reaching technological applications of composite materials.

Adhesion in Microelectronics

Adhesion in Microelectronics PDF Author: K. L. Mittal
Publisher: John Wiley & Sons
ISBN: 1118831349
Category : Technology & Engineering
Languages : en
Pages : 293

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Book Description
This comprehensive book will provide both fundamental and applied aspects of adhesion pertaining to microelectronics in a single and easily accessible source. Among the topics to be covered include; Various theories or mechanisms of adhesion Surface (physical or chemical) characterization of materials as it pertains to adhesion Surface cleaning as it pertains to adhesion Ways to improve adhesion Unraveling of interfacial interactions using an array of pertinent techniques Characterization of interfaces / interphases Polymer-polymer adhesion Metal-polymer adhesion (metallized polymers) Polymer adhesion to various substrates Adhesion of thin films Adhesion of underfills Adhesion of molding compounds Adhesion of different dielectric materials Delamination and reliability issues in packaged devices Interface mechanics and crack propagation Adhesion measurement of thin films and coatings

Plasma Technologies for Textiles

Plasma Technologies for Textiles PDF Author: Roshan Shishoo
Publisher: Elsevier
ISBN: 1845692578
Category : Technology & Engineering
Languages : en
Pages : 353

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Book Description
Plasma technologies present an environmentally-friendly and versatile way of treating textile materials in order to enhance a variety of properties such as wettability, liquid repellency, dyeability and coating adhesion. Recent advances made in commercially viable plasma systems have greatly increased the potential of using plasma technology in industrial textile finishing. This pioneering book provides an essential guide to both the technology and science related to plasmas and its practical applications in the textile industry. The first part of the book discusses the science and technology behind plasmas. Chapters give detailed and comprehensive descriptions on the characteristics of plasmas and methods of control and treatment in the processing of textiles. Both low pressure cold plasma and atmospheric pressure cold plasma processes are described as well as the diagnosis and control of plasma parameters in plasma generating reactors. A chapter is devoted to the use of plasma technology to achieve nanoscale treatment of textile surfaces. The second part of the book concentrates on specific applications of plasma technologies. Chapters cover treatments for water and oil repellency of textiles, engineering of biomedical textiles and woollen finishing techniques through the use of plasma technologies. Further chapters cover the modification of fibres for use in composites and the potential use of plasma technologies for the finishing of fabrics made of man made fibres. The final chapter in the book gives a comprehensive analysis of the surface chemical and physical characterisation of plasma treated fabrics. Written by a distinguished international team of experts, Plasma technologies for textiles is an invaluable reference for researchers, scientists and technologists alike. Summarises both the science and technology of plasma processing, and its practical applications Discusses how plasma technology improves textile properties such as wettability and liquid repelling An invaluable reference for researchers, scientists and technologists

Atmospheric Pressure Plasma for Surface Modification

Atmospheric Pressure Plasma for Surface Modification PDF Author: Rory A. Wolf
Publisher: John Wiley & Sons
ISBN: 1118547551
Category : Technology & Engineering
Languages : en
Pages : 268

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Book Description
This Book's focus and intent is to impart an understanding of the practical application of atmospheric plasma for the advancement of a wide range of current and emerging technologies. The primary key feature of this book is the introduction of over thirteen years of practical experimental evidence of successful surface modifications by atmospheric plasma methods. It offers a handbook-based approach for leveraging and optimizing atmospheric plasma technologies which are currently in commercial use. It also offers a complete treatment of both basic plasma physics and industrial plasma processing with the intention of becoming a primary reference for students and professionals. The reader will learn the mechanisms which control and operate atmospheric plasma technologies and how these technologies can be leveraged to develop in-line continuous processing of a wide variety of substrates. Readers will gain an understanding of specific surface modification effects by atmospheric plasmas, and how to best characterize those modifications to optimize surface cleaning and functionalization for adhesion promotion. The book also features a series of chapters written to address practical surface modification effects of atmospheric plasmas within specific application markets, and a commercially-focused assessment of those effects.