The Effects of Molecular Orientation on the Physical Aging Behavior of Oriented Glassy Amorphous Polymers PDF Download

Author: Marcus David Shelby
Publisher:
ISBN:
Category :
Languages : en
Pages : 580

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Author: Steven E. Keinath
Publisher: Springer Science & Business Media
ISBN: 146131867X
Category : Technology & Engineering
Languages : en
Pages : 478

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Book Description
In 1975, a symposium was held in Midland, Michigan, co-sponsored by the Dow Chemical Company and the then Midland Macromolecular Institute in honor of Raymond F. Boyer on the occasion of his 65th birthday and retirement from Dow. The topic of that first Boyer symposium dealt with an area of interest to Boyer, namely, polymer transitions and relaxations. One decade later, after ten years of additional fruitful scientific endeavor at MMI, Ray Boyer was again honored with a symposium, this time celebrating his 75th birthday and 10th anniversary at the Michigan Molecular Institute. The topic of the second Boyer symposium in 1985 was somewhat more focused, this time concentrating on the subject of order (or structure) in the amorphous state of polymers and the attendant polymer transitions that are observed. This volume contains the full manuscripts of the contributors to the 17th MMI International Symposium, held in Midland, Michigan on August 18-21, 1985. Eleven one-hour plenary lectures and ten 20-minute contributed papers were presented during the Symposium. An open forum panel discussion was also scheduled; the edited transcript of that session is included at the end of this volume. One of our tasks in organizing this Symposium was to attempt to gather together a number of speakers who would be able to define what, if any, physical structure might be present in anwrplwus polymers and what the nature of this order might be.

Author: Angel Cugini
Publisher:
ISBN:
Category :
Languages : en
Pages :

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This thesis focuses on unconventional methods to improve the mechanical properties of glassy polymers such as PMMA, TritanTM Copolyester, and epoxy-based thermosets by influencing the intrinsic mechanical behavior through solid-state processing. The solid-state processing includes pre-stress, mechanical rejuvenation, and mechanical work hardening that cause changes in microscopic conformation structure and dynamics of glassy polymers and enhance properties such as non-linear deformation behavior and low and high velocity fracture. To utilize such unconventional techniques, one needs to understand fundamental origins of dynamics in polymeric glasses where the chain segments are not completely frozen and the segmental diffusion displays high degree of intermolecular cooperativity. We demonstrate how fundamental principles of polymer physics can be applied to improve fracture toughness of polymeric glasses. Emphasis is placed on structure-process-property relationships of these systems. In Chapter 2 long-term effects of physical aging and solid state processing are monitored through dynamic mechanical properties of an amorphous glassy polymer. These phenomena are investigated through dynamic mechanical testing that evaluates in-situ the evolution of the storage modulus with time during annealing and physical aging. Comparisons are made on samples with different thermal histories and mechanical treatment. The results are discussed in context to an aging rate obtained from the various thermal and mechanical treatments. We demonstrate that there is apparent work hardening of glassy polymers. The effect of strain rate, dwell time and material are compared and the permanence of the processing is investigated. In Chapter 3, we investigate the effect mechanical rejuvenation on the fracture toughness of epoxy-based thermosets and correlate the kinetics of the recovery of fracture toughness to compression based ductility parameters and dynamic mechanical analysis (DMA)-based aging rates. We also investigate the effect of molecular additives, antiplasticizers, on the structural recovery rate of the epoxy after mechanical rejuvenation. Chapter 4 studies the optimization of prestressed poly (methyl methacrylate) (PMMA), through equibiaxial compression with increasing amounts of shear and simple shear. To suppress inherent large radial crack growth associated with simple shear prestress, orientation is superimposed to minimize crack growth. These prestressed states are compared at both low velocity and ballistic rates. To investigate the low velocity impact dependence on rate, a strain energy density term is used to remove the dependence of geometry. Lastly, to reduce scatter in ballistic date, a master curve is developed to collapse all data regardless of boundary conditions, rate of impact and materials. In Chapter 5 we examine the correlation between ductility parameters based on dynamic mechanical data and fracture toughness and other non-linear mechanical properties. This chapter focuses on the model system poly (methyl methacrylate) and the relationship of these ductility parameters to other engineering properties for a range of temperatures and strain rates.

Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 756

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Author: Martin R. Tant
Publisher:
ISBN:
Category : Medical
Languages : en
Pages : 486

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Book Description
In twenty-nine chapters by leading authorities, Structure and Properties of Glassy Polymers provides readers with comprehensive coverage of basic and applied research on glass polymers as well as a wealth of information on current topics such as molecular modeling, characterization, polymer glasses in confined spaces, and conducting glass polymers. The characterization techniques presented include temperature-modulated differential scanning calorimetry, dielectric loss spectroscopy, photochemical hole burning, positron annihilation lifetime spectroscopy, and transient current generation.

Author: G. Bodor
Publisher: John Wiley & Sons
ISBN:
Category : Science
Languages : en
Pages : 446

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Book Description
Good,No Highlights,No Markup,all pages are intact, Slight Shelfwear,may have the corners slightly dented, may have slight color changes/slightly damaged spine.

Author: Richard E. Gahan
Publisher:
ISBN:
Category : Polymers
Languages : en
Pages : 276

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Author: Yang-Lioe
Publisher:
ISBN:
Category : Deformations (Mechanics)
Languages : en
Pages : 538

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Author: Dale J. Meier
Publisher: CRC Press
ISBN: 9780677112404
Category : Mechanical chemistry
Languages : en
Pages : 452

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Author: Nikhil Padhye
Publisher: Springer Nature
ISBN: 3030825590
Category : Science
Languages : en
Pages : 111

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Book Description
This book bridges disparate fields in an exploration of the phenomena and applications surrounding molecular mobility in glassy materials experiencing inelastic deformation. The subjects of plastic deformation and polymer motion/interdiffusion currently belong to the two different fields of continuum mechanics and polymer physics, respectively. However, molecular motion associated with plastic deformation is a key ingredient to gain fundamental understanding, both at the macroscopic and microscopic level. This short monograph provides necessary background in the aforementioned fields before addressing the topic of molecular mobility accompanied by macroscopic inelastic deformation in an accessible and easy-to-understand manner. A new phenomenon of solid-state deformation-induced bonding in polymers is discussed in detail, along with some broad implications in several manufacturing sectors. Open questions pertaining to mechanisms, mechanics, and modeling of deformation-induced bonding in polymers are presented. The book’s clear language and careful explanations will speak to readers of diverse backgrounds.