Download or read book Viscoelastic Properties of Crystalline Block Copolymers written by Umesh Kumar Mehra and published by . This book was released on 1973 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Time dependent Morphologies and Viscoelastic Properties of Block Copolymers written by Jeffrey Carl Kelterborn and published by . This book was released on 1981 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamic mechanical properties of block copolymers over a wide temperature range have been previously correlated with the phase-separated microstructure of these systems. In the present work the morphology of the block copolymer is altered by large tensile deformation at various temperatures. Upon removal of the applied stress the morphological features of such stretched-and-released systems become functions of time, as the non-equilibrium microstructure reverts to a thermodynamically stable state. This reformation process is monitored by dynamic mechanical measurements with a modified torsion pendulum capable of applying both tensile and torsional deformation. Experimental results are analyzed using a modified Nielsen model to obtain information on the time-dependent structural state of the samples. These results are then compared with stress-strain curves to provide further insight into the structure breakdown-reformation mechanisms. Two competing mechanisms, domain fracture and block pull out, are proposed to explain these experimental observations. (Author).

Download or read book Viscoelastic Properties of Block Copolymer homopolymer Blends written by Lester Tungnan Toy and published by . This book was released on 1974 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscoelastic Properties of Homogeneous Block Copolymers written by David Romme Hansen and published by . This book was released on 1975 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscoelastic Properties of Homogeneous Block Copolymers and Entangled Monodisperse Homopolymers written by David Syhlih Soong and published by . This book was released on 1977 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscoelastic Properties of Homogeneous Block Copolymers written by M. Shen and published by . This book was released on 1977 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The molecular theory of Rouse-Bueche-Zimm has been modified to predict the viscoelastic behavior of homogeneous block copolymers. The model consists of beads and springs whose magnitudes correspond to the types of blocks in the polymer. Maximum relaxation times can be computed by this model. Viscoelastic data for poly(styrene-b-alpha-methylstyrene-b-styrene), poly(alpha-methylstyrene-b-styrene-b-alpha-methylstyrene) and poly(styrene-b-alpha-methylstryrene) were determined by stress relaxation methods. The results compare favorably with those predicted by the theory. (Author).

Download or read book Viscoelastic Properties of Polymers written by John D. Ferry and published by John Wiley & Sons. This book was released on 1980-09-16 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Viscoelastic behavior reflects the combined viscous and elastic responses, under mechanical stress, of materials which are intermediate between liquids and solids in character. Polymers the basic materials of the rubber and plastic industries and important to the textile, petroleum, automobile, paper, and pharmaceutical industries as well exhibit viscoelasticity to a pronounced degree. Their viscoelastic properties determine the mechanical performance of the final products of these industries, and also the success of processing methods at intermediate stages of production. Viscoelastic Properties of Polymers examines, in detail, the effects of the many variables on which the basic viscoelastic properties depend. These include temperature, pressure, and time; polymer chemical composition, molecular weight and weight distribution, branching and crystallinity; dilution with solvents or plasticizers; and mixture with other materials to form composite systems. With guidance by molecular theory, the dependence of viscoelastic properties on these variables can be simplified by introducing certain ancillary concepts such as the fractional free volume, the monomeric friction coefficient, and the spacing between entanglement loci, to provide a qualitative understanding and in many cases a quantitative prediction of how to achieve desired results. The phenomenological theory of viscoelasticity which permits interrelation of the results of different types of experiments is presented first, with many useful approximation procedures for calculations given. A wide variety of experimental methods is then described, with critical evaluation of their applicability to polymeric materials of different consistencies and in different regions of the time scale (or, for oscillating deformations, the frequency scale). A review of the present state of molecular theory follows, so that viscoelasticity can be related to the motions of flexible polymer molecules and their entanglements and network junctions. The dependence of viscoestic properties on temperature and pressure, and its descriptions using reduced variables, are discussed in detail. Several chapters are then devoted to the dependence of viscoelastic properties on chemical composition, molecular weight, presence of diluents, and other features, for several characteristic classes of polymer materials. Finally, a few examples are given to illustrate the many potential applications of these principles to practical problems in the processing and use of rubbers, plastics, and fibers, and in the control of vibration and noise. The third edition has been brought up to date to reflect the important developments, in a decade of exceptionally active research, which have led to a wider use of polymers, and a wider recognition of the importance and range of application of viscoelastic properties. Additional data have been incorporated, and the book s chapters on dilute solutions, theory of undiluted polymers, plateau and terminal zones, cross-linked polymers, and concentrated solutions have been extensively rewritten to take into account new theories and new experimental results. Technical managers and research workers in the wide range of industries in which polymers play an important role will find that the book provides basic information for practical applications, and graduate students in chemistry and engineering will find, in its illustrations with real data and real numbers, an accessible introduction to the principles of viscoelasticity.

Download or read book Characterization of Block Copolymers Based on Poly 3 3 bis ethoxymethyl oxetane and Other Novel Polyethers written by K. E. Hardenstine and published by . This book was released on 1984 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present study involves crystalline block copolymers based on poly(3,3-bis(ethoxymethyl)oxetane, polyBEMO, and random copolymers based on other either forming monomers. The objective of the work is to generate a block copolymer consisting of crystallizable polyether end blocks based on poly(BEMO) and an amorphous rubbery center block based on the polyether random copolymers. This paper will examine the interrelationships among glass and melting transition behavior, viscoelastic characteristics, tensile properties, and morphological features of these new block copolymers. The properties of the block copolymers will be compared with those of the homopolymer poly(BEMO).

Download or read book Viscoelastic and Transport Properties of Sulfonated PS PIB PS Block Copolymers written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Morphology, viscoelastic, and transport properties of the sulfonated polystyrene-polyisobutylene-polystyrene (PS-PIB-PS) block copolymer were investigated with respect to sulfonation level and counter-ion substitution. Dynamic mechanical analysis (DMA) was used to examine the dynamic storage modulus E' and dynamic loss modulus E", as they relate to changes in sulfonation levels. Small-angle x-ray scattering (SAXS) results confirmed that at a certain percent of sulfonation, a phase transition occurs from hexagonally packed cylinders to lamellar structure due to swelling of the styrene domains caused by the higher sulfonation levels. Transport measurements using Fourier Transfer Infrared Spectrometer (FTIR) confirm that the sulfonation level directly dictates the transport rate of small molecules (alcohol and water) through the PS-PIB-PS triblock copolymer membrane. Faster water transport can be achieved by incorporating more sulfonic acid groups throughout the polymer backbone. In addition, infrared (IR) data clearly identifies molecular interactions between the solvating alcohol molecules and the PS-PIB-PS triblock copolymer. The observed properties suggest that these ion-containing block copolymers are worthy of further development as barrier membranes to be incorporated into chemical protective clothing.

Download or read book Linear Viscoelastic Properties of Homogeneous Bulk Polymers written by David Syhlih Soong and published by . This book was released on 1978 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Block Number on the Order disorder Transition Viscoelastic Properties and Shear Alignment Behavior of Linear AB n Multiblock Copolymers written by Lifeng Wu and published by . This book was released on 2004 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscoelastic Properties of Crystalline Polymers Polyethylene written by E. Catsiff and published by . This book was released on 1955 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Investigations of Block Copolymer Melts and Solutions written by Mary Beth Kossuth and published by . This book was released on 1999 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscoelastic Properties of Some Crystalline Polymers written by R. W. Gray and published by . This book was released on 1969 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oscillatory Flow Birefringence and Linear Viscoelasticity of Block Copolymers written by Donald M. Parsons and published by . This book was released on 1994 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Properties of Polymers written by D.W. van Krevelen and published by Elsevier. This book was released on 2012-12-02 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: Properties of Polymers: Their Correlation with Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions summarizes the latest developments regarding polymers, their properties in relation to chemical structure, and methods for estimating and predicting numerical properties from chemical structure. In particular, it examines polymer electrical properties, magnetic properties, and mechanical properties, as well as their crystallization and environmental behavior and failure. The rheological properties of polymer melts and polymer solutions are also considered. Organized into seven parts encompassing 27 chapters, this book begins with an overview of polymer science and engineering, including the typology of polymers and their properties. It then turns to a discussion of thermophysical properties, from transition temperatures to volumetric and calorimetric properties, along with the cohesive aspects and conformation statistics. It also introduces the reader to the behavior of polymers in electromagnetic and mechanical fields of force. The book covers the quantities that influence the transport of heat, momentum, and matter, particularly heat conductivity, viscosity, and diffusivity; properties that control the chemical stability and breakdown of polymers; and polymer properties as an integral concept, with emphasis on processing and product properties. Readers will find tables that give valuable (numerical) data on polymers and include a survey of the group contributions (increments) of almost every additive function considered. This book is a valuable resource for anyone working on practical problems in the field of polymers, including organic chemists, chemical engineers, polymer processers, polymer technologists, and both graduate and PhD students.

Download or read book Amphiphilic Block Copolymers written by P. Alexandridis and published by Elsevier. This book was released on 2000-10-18 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is the belief of the editors of this book that the recognition of block copolymers as being amphiphilic molecules and sharing common features with other well-studied amphiphiles will prove beneficial to both the surfactant and the polymer communities. An aim of this book is to bridge the two communities and cross-fertilise the different fields. To this end, leading researchers in the field of amphiphilic block copolymer self-assembly, some having a background in surfactant chemistry, and others with polymer physics roots, have agreed to join forces and contribute to this book.The book consists of four entities. The first part discusses theoretical considerations behind the block copolymer self-assembly in solution and in the melt. The second part provides case studies of self-assembly in different classes of block copolymers (e.g., polyethers, polyelectrolytes) and in different environments (e.g., in water, in non-aqueous solvents, or in the absence of solvents). The third part presents experimental tools, ranging from static (e.g., small angle neutron scattering) to dynamic (e.g., rheology), which can prove valuable in the characterization of block copolymer self-assemblies. The fourth part offers a sampling of current applications of block copolymers in, e.g., formulations, pharmaceutics, and separations, applications which are based on the unique self-assembly properties of block copolymers.