Download or read book Experimental Investigation of Polymer Adhesion Mechanics Using a Blister Contact Test written by Nathan Ip and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The adhesion of thin layers of soft polymers is important in many applications, such as tapes, microtransfer printing, and bioinspired adhesives. Traditional adhesion tests based on probe contacts are not suitable for characterizing thin layers and common separation-based specimens, such as the peel test, have well-known limitations. The blister contact test (BCT) was developed in this dissertation to overcome the limitations of current methods and was used to investigate the adhesion and separation of several technologically relevant adhesive systems. In the BCT, a thin sheet was elastically deformed into adhesive contact with a reference substrate and the contact area was optically imaged. Modulated pressure was applied to generate both advancing and receding adhesive contact. Digital image correlation was used to measure the displacements of the specimen. The strain energy release rate at the interface was determined from the measured contact radius, applied pressure, system geometry, and elastic properties of the specimen using a mechanics model. An analytical mechanics model based on von Kármán plate theory was developed and used for analysis of the BCT data. Finite element analysis was used to validate and identify the range of applicability of the analytical model. The BCT was used to investigate the adhesion and separation behaviors of three different polymer adhesive systems. First, experiments between a silicone elastomer (polydimethylsiloxane--PDMS) and a stiff substrate were performed to investigate rate effects in adhesion and separation. For the first time, the rate dependence during advancing contact was characterized. Second, the effect of acid-base interactions on performance of pressure sensitive adhesives (PSAs) was examined via a series of BCTs in which adhesion between different formulations of adhesives and multiple substrates was investigated. Viscoelastic contributions to PSA adhesion were also studied. Finally, the effect of layer thickness on rate dependence was investigated through experiments between polyethylene terephthalate (PET) sheets and PDMS films of different thicknesses. The work in this dissertation demonstrates the flexibility and capability of the BCT as a method to characterize adhesion of flat polymer sheets and provides new understanding of several types of polymer adhesive contacts.
Download or read book Investigation of Adhesion and Fracture of the Polymer oxide Interfaces Using Rolling Contact Mechanics written by Honquan She and published by . This book was released on 2002 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the very basic origin, the adhesion strength or fracture resistance of contacting interfaces results from intermolecular forces. When interface is separated, external energy is provided to the system, which eventually is dissipated in the form of mechanical deformation of the bulk material and cleavage of the interfacial bonds. The objective of this study is to understand the energy dissipation mechanism of interfacial fracture. It particularly includes polymer molecular weight and rate dependent properties of fracture. The model system consists of an oxidized polydimethylsiloxane(PDMS)-made hemicylinder and a PDMS thin films substrate, in which system energy is mainly dissipated at the interface layer. A unique experimental methodology---rolling contact mechanics method is developed by rolling the hemi-cylinder on the test substrate at a uniform velocity, the contact deformation of which is used to estimate the energy dissipation governed by non-equilibrium processes occurred at the interface. The strong molecular weight dependent fracture energy can be explained in terms of polymer chain extension and relaxation, which has its origins in the classic Lake-Thomas theory. The fracture energy is amplified by the molecular weights of polymers which bridge the open interface. The rate effect can be explained using the kinetic theory of thermally activated bond rupture, the results of which point out that this molecular weight dependent Lake-Thomas effect is purely a non-equilibrium effect and isn't compatible with the traditional notion of equilibrium fracture. The energy dissipation occurred at the interface can now be understood under the framework which combined chain elasticity and interfacial kinetics.
Download or read book Applications of Contact and Fracture Mechanics to Studies of Polymer Adhesion written by James Michael Baney and published by . This book was released on 2000 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1989 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contact Mechanics Studies of Polymer Thin Film Adhesion written by Rachel Lynn McSwain and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The work presented in this dissertation focuses on using the unique abilities of the JKR technique to probe the interfacial interactions of two independent polymer systems. To perform these studies, modifications were made to the JKR technique, including the integration of a thermal cycle to enable testing of thermally initiated interfacial interactions between two materials. Another enhancement of the JKR technique involved incorporation of cyclic testing to study crack growth under fatigue conditions.
Download or read book Polymer polymer Adhesion Promotion by Block copolymer Addition written by Ralf Brian Mason and published by . This book was released on 2002 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Performance Polymer written by Guy Rabilloud and published by Editions OPHRYS. This book was released on with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adhesion and Wear of Nanoscale Polymer Contacts written by Chen Jiang and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic force microscopy (AFM) is a powerful tool for high resolution surface measurements, nanolithography, and tip-based nanomanufacturing. An understanding of the nanoscale tribological behavior of the tip-sample contact, including adhesion and wear, is critical in these applications. In this dissertation, the adhesion and wear of polymethyl methacrylate (PMMA) in contact with an ultrananocrystalline diamond (UNCD) AFM tip is investigated using a combination of AFM-based nanomechanics experiments and finite element analysis (FEA). A novel AFM-based method, which combines pull-off force measurements and characterization of the 3D geometry of AFM tip, was developed to quantify the properties of the adhesive traction-separation relationship of UNCD-PMMA contacts. Adhesion range and strength, as well as work of adhesion, of the contacts were determined. Characterizing and understanding nanoscale wear of polymers has proven difficult in the past due to experimental complications associated with debris produced in the tests and the failure of traditional empirical wear relations, such as Archard's law. Here, nanoscale AFM-based line and raster wear experiments were performed on patterned PMMA structures, which had gaps that allow debris to be captured. Results from the line wear tests indicate that the relationship between height loss rate and stress is well described by a transition state theory wear model. The wear parameters obtained from line wear tests were applied to predict the volume loss in raster wear tests. Despite the significant differences in the loading and sliding geometry between line and raster wear experiments, the raster wear behavior was accurately predicted from the parameters obtained from line wear tests. In addition, experiments at varying temperatures were performed to study the temperature dependence of polymer wear. The results suggest that transition state theory overestimates the effect of temperature on wear for PMMA. Modified models considering viscoelastic relaxation of PMMA and atom-by-atom attrition were applied to describe the measured wear behavior. Finally, an iterative FEA method was developed for simulations of wear. These simulations were used to examine the evolution of geometry and stress during the wear process as a function of contact conditions, such as friction and surface roughness.
Download or read book Adhesion of Polymers written by Vladimir Kestelman and published by McGraw Hill Professional. This book was released on 2001-12-05 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current applications for bonding and sealing are expensive and time-consuming. Adhesion of Polymers presents a state-of-the-art method for improving bonds and sealing strength between different materials underwater and in the human body. This time- and cost-efficient technology will allow engineers to create or repair stronger seals in underwater pipes, repair ships at sea, even bond and seal tissues in the body.
Download or read book Challenges in Mechanics of Time Dependent Materials Volume 2 written by Bonnie Antoun and published by Springer. This book was released on 2016-09-20 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Challenges in Mechanics of Time-Dependent Materials, Volume 2 of the Proceedings of the 2016 SEM Annual Conference& Exposition on Experimental and Applied Mechanics, the second volume of ten from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and applied aspects of Experimental Mechanics, including papers in the following general technical research areas: Extreme Environments & Environmental Effects Structure-Function of Performance of PE Effects of Inhomogeneities & Interfaces Characterization Across Scales Mechanics of Energy & Energetic Materials Metallic Materials Viscoelasticity & Viscoplasticity
Download or read book Extended Abstracts written by Electrochemical Society and published by . This book was released on 1991 with total page 1304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contact Mechanics of Polymer Interfaces written by Attila Oláh and published by . This book was released on 2004 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PRO 9 2nd International RILEM Symposium on Adhesion between Polymers and Concrete ISAPP 99 written by Yoshihiko Ohama and published by RILEM Publications. This book was released on 1999 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Adhesion Using the Island Blister Test written by Scott Anthony Sikorski and published by . This book was released on 1994 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adhesion written by Wulff Possart and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emphasizing the most recent developments this book addresses both the basic and applied aspects of adhesion. The authors present the latest results on fundamental aspects, adhesion in biology, chemistry for adhesive formulation, surface chemistry and the pretreatment of adherends, mechanical issues, non-destructive testing and the durability of adhesive joints, as well as advanced technical applications of adhesive joints. Prominent scientists review the current level of knowledge concerning the role of chemical bonds in adhesion, new resins and nanocomposites for adhesives, and about the role played by macromolecular architecture in the properties of hot melt and pressure sensitive adhesives. Written by 34 acknowledged experts from academic and industrial research facilities, this is a valuable source of information for chemists, physicists, biologists and engineers, as well as graduate students interested in fundamental and practical adhesion.
Download or read book A Polymer Cochlear Electrode Array Atraumatic Deep Insertion Tripolar Stimulation and Long Term Reliability written by Tae Mok Gwon and published by Springer. This book was released on 2018-05-24 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the design, fabrication and evaluation of a polymer-based neural interface for a cochlear electrode array, reviewed in terms of fabrication process, functionality, and reliability. Polymer-based devices have attracted attention in the neural prosthetic field due to their flexibility and compatibility with micro-fabrication process. A liquid crystal polymer (LCP) is an inert, highly water-resistant polymer suitable for the encapsulation of electronic components and as a substrate material for fabricating neural interfaces. The author has designed, fabricated, and evaluated an LCP-based cochlear electrode array for an improved polymer-based cochlear implant. The thesis deals with 3 key topics: atraumatic deep insertion, tripolar stimulation, and long-term reliability. Atraumatic insertion of the intracochlear electrode and resulting preservation of residual hearing have become essential in state–of-the-art cochlear implantation. A novel tapered design of an LCP-based cochlear electrode array is presented to meet such goals. For high-density and pitch-recognizable cochlear implant, channel interaction should be avoided. Local tripolar stimulation using multi-layered electrode sites are shown to achieve highly focused electrical stimulation. This thesis addresses another vital issue in the polymer-based neural implants: the long-term reliability issue. After suggesting a new method of forming mechanical interlocking to improve polymer-metal adhesion, the author performs accelerating aging tests to verify the method’s efficacy. The aforementioned three topics have been thoroughly examined through various in vitro and in vivo studies. Verification foresees the development of LCP-based cochlear electrode array for an atraumatic deep insertion, advanced stimulation, and long-term clinical implant.
