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Books > Science & Mathematics > Chemistry > Organic chemistry > Polymer chemistry
In many cases rheological measurements are carried out in the
simplest of geometries, but the interpretation involved in
obtaining the rheological parameters of the test fluids from these
measurements is surprisingly complex. The purpose of this book is
to emphasise the points on which most workers in the field agree,
and to let the authors deal with the contentious points according
to their own beliefs and experience. This work represents a summary
of the current thought on rheological meas urement by experts in
the various techniques. When making measurements and obtaining from
them parameters that describe the flow behaviour of the test
fluids, it is essential that the experimentalist understands the
underlying theory and shortcomings of the measurement technique,
that he is aware of the likely microstructure of the fluid, and
that from this he can appreciate how the fluid and the measuring
system will interact with each other. It is this interaction that
gives both the required rheological parameters of the fluids and
the artefacts that confuse the issue. This book covers the main
rheological measurement techniques from capillary, slit and
stretching flows to rotational and oscillatory rheometry in various
geometries including sliding plate measurements. These topics are
backed up by chapters on more practical aspects, such as commercial
instruments, and on computer control and data acquisition. The
chapters deal with the basic methods, how the measurements are
taken, and what assumptions and interpretations are made to obtain
valid data on the test fluids."
Toyiochi Tanaka, Mitsuhiro Shibayama, "Phase Transitions and
related Phenomena of Polymer Gels", Akira Onuki "Theory of Phase
Transition in Polymer Gels", Alexei Khokhlov, Sergei Starodybtzev,
Valentina Vasilevskaya "Conformational Transitions in Polymer Gels:
Theory and Experiment", Michal Ilavsky " Effect on Phase Transition
on Swellingand Mechanical Behavior of Synthetic Hydrogels",
Shozaburo Saito , M. Konno, H. Inomata "Volume Phase Transition of
N-Alkylacrylamide Gels", Ronald Siegel "Hydrophobic Weak
Polyelectrolyte Gels: Studies of Swelling Equilibria and Kinetics".
The incessantly interest in aqueous polymer dispersions (APD)
since more than 90 years can be related to the almost unlimited
possibilities to tailor APD to specific needs.
These proceedings from an international symposium on "Polymer
Colloids: Preparation & Properties of Aqueous Polymer
Dispersions" held at the Swabian Conference Center (Kloster Irsee,
Germany) witness this statement.
The 33 contributions cover important aspects of APD such as control
of particle size and stabilization, different polymerization
technologies, applications as binders, paints, or as supports for
proteins and hence, span the whole range from academic to
practical.
The renewed and increasing interest in lipid self-assembly, phase
behaviour and interfacial properties can be related to both a much
improved insight in biological systems and the applications of
lipids in food and pharmaceutical industry; in the latter, the
development of drug delivery systems based on lipids has become in
focus. Amphiphilic systems comprise lipids, surfactants as well as
different types of polymers, including block and graft copolymers.
Research on biological amphiphiles has often been conducted
separate from research on synthetic ones. However, in recent years
a very fruitful convergence between the two fields has evolved.
These new perspectives on fundamental research and applications of
lipids are discussed in these proceedings from an international
symposium on "Lipid and Polymer Lipid-systems," October 2000 in
Chia Laguna in Italy - a joint undertaking of Prof. Maura Monduzzi
at Cagliari University, Italy and Camurus Lipid Research
Foundation, Lund, Sweden.
Viscoelasticandtransportpropertiesofpolymersintheliquid(solution,melt)or
liquid-like (rubber) state determine their processing and
application to a large extent and are of basic physical interest
[1-3]. An understanding of these dynamic properties at a molecular
level, therefore, is of great importance.
However,thisunderstandingiscomplicatedbythefactsthatdi?erentmotional
processes may occur on di?erent length scales and that the dynamics
are governed by universal chain properties as well as by the
special chemical structure of the monomer units [4,5]. The earliest
and simplest approach in this direction starts from Langevin
equations with solutions comprising a spectrum of relaxation modes
[1-4]. Special features are the incorporation of entropic forces
(Rouse model, [6]) which relax uctuations of reduced entropy, and
of hydrodynamic interactions (Zimm model, [7]) which couple
segmental motions via long-range back ow elds in polymer solutions,
and the inclusion of topological constraints or entanglements
(reptation or tube model, [8-10]) which are mutually imposed within
a dense ensemble of chains. Another approach, neglecting the
details of the chemical structure and
concentratingontheuniversalelementsofchainrelaxation,isbasedondynamic
scalingconsiderations[4,11].Inparticularinpolymersolutions,thisapproach
o?ers an elegant tool to specify the general trends of polymer
dynamics, although it su?ers from the lack of a molecular
interpretation. A real test of these theoretical approaches
requires microscopic methods, which simultaneously give direct
access to the space and time evolution of the segmental di?usion.
Here, quasi-elastic scattering methods play a crucial role
sincetheyallowthemeasurementofthecorrespondingcorrelationfunctions.In
particular,thehigh-resolutionneutronspinecho(NSE)spectroscopy[12-15]is
very suitable for such investigations since this method covers an
appropriate range in time (0.005)t/ns)40) and space (r/nm [15).
Furthermore, the
possibilityoflabellingbyhydrogen-deuteriumexchangeallowstheobservation
of single-chain behavior even in the melt.
Leading Nordic-Baltic scientists and their colleagues from other
countries present recent research on a broad range of topics in
surface and colloid science: adhesion, adsorption processes,
characterization of solid/liquid and solid/polymer interfaces,
chemical and particle depositions, colloid stability,
emulsification and encapsulation, interfacial reactions, new
surfactants, polymer-surfactant interactions, self-assembly
processes, and functionalized surfaces for bio- and chemosensors.
The papers were presented at the 1st Nordic-Baltic Meeting on
Surface and Colloid Science, which was held in Vilnius, Lithuania
on August 21-25, 1999, as a continuation of the traditional
Scandinavian Symposium on Surface Chemistry.
The Fifth Chinese Peptide Symposium, hosted by Lanzhou University,
was held at Lanzhou, China July 14-17, 1998, with 156 participants,
including 30 scientists from abroad, representing nine countries.
The four-day conference was both intense and spiritually rewarding.
Our goal for CPS-98 was to provide a forum for the exchange of
knowledge, cooperation and friendship between the international and
Chinese scientific communities, and we believe this goal was met.
The symposium consisted of 8 sessions with 42 oral and 90 poster
presentations, including synthetic methods, molecular diversity and
peptide libraries, structure and conformation of peptides and
proteins, bioactive peptides, peptide immunology, De Novo design
and synthesis of proteins and peptides, ligand-receptor
interactions, the chemistry-biology-interface and challenging
problems in peptides. The enthusiastic cooperation and excellent
contributions were gratifying and the active response of the
invited speakers contributed to the success of the symposium. The
presentations were of excellent caliber and represented the most
current and significant aspects of peptide science. Dr. Kit Lam of
the University of Arizona and Dr. Yun-Hua Ye of Peking University
were the recipients of "The Cathay Award" sponsored by the H. H.
Liu Education Foundation, offered for their seminal contribution in
peptide science and the Chinese Peptide Symposium. Four outstanding
young scientists were selected by the organizing committee to
receive awards sponsored by Haikou Nanhai Pharmaceutical Industry
Co. Ltd. (Zhong He Group).
Shunsuke Hirotsu "Coexistence of Phases and the Nature of
First-Order Transition in Poly-N-isopropylacrylamide Gels,"
Masayuki Tokita "Friction between Polymer Networks of Gels and
Solvent," Masahiro Irie "Stimuli-Responsive Poly(N-isopropyl-
acrylamide), Photo- and Chemicals-Induced Phases Transitions Edward
Cussler, Karen Wang, John Burban"Hydrogels as Separation Agents,"
Stevin Gehrke "Synthesis, Equilibrium Swelling, Kinetics
Permeability and Applications of Environmentally Responsive Gels,"
Pedro Verdugo "Polymer Gel Phase Transition in Condensation-
Decondensation of Secretory Products," Etsuo Kokufuta "Novel
Applications for Stimulus-Sensitive Polymer Gels in the Preparation
of Functional Immobilized Biocatalysts," Teruo Okano "Molecular
Design of Temperature-Responsive Polymers as Intelligent
Materials," Atsushi Suzuki "Phase Transition in Gels of
Sub-Millimeter Size Induced by Interaction with Stimuli," Makoto
Suzuki, O. Hirasa "An Approach to Artificial Muscle by Polymer Gels
due to Micro-Phase Separation."
This volume of the series gives an overview on Rigid Polymer
Networks written by two reputed experts in the field. A broad range
of densely-branched, highly-crosslinked aromatic networks and gels
of increasing rigidity are discussed, with special emphasis on
aromatic rigid liquid-crystal polymer networks. The synthetic
procedures to create the networks are briefly described and
extensively referenced. Features of one-step and two-step rigid
networks in their pre-gel and post-gel states are discussed. Some
first steps are then taken in the theoretical treatment of LCP
networks with long aromatic segments of decreasing stiffness. The
current state of theory dealing with the broader class of
highly-crosslinked rigid aromatic networks and gels is finally
mentioned.
This book summarizes the properties and applications of
conventional and commercially available fiber-forming,
bioresorbable polymers, as well as those currently under study, for
use as biotextiles. Factors affecting the performance of these
biomaterials are presented, and precautionary measures to reduce
premature, hydrolytic degradation during manufacturing and
processing are discussed. Because of the structural requirements of
medical devices and the technological advancements in synthetic
fibers and textile technology, the new field of "Biotextiles" has
evolved to exploit the potential of various woven, knitted, braided
and non-woven textile structures for biomedical applications.
Textile substrates provide certain unique mechanical properties to
the medical device and because of an inherently high level of
porosity, they can encourage cell growth and promote migration and
proliferation. Bioresorbable devices that assist in the repair and
regeneration of damaged tissues have in recent years replaced many
of the permanent prosthetic devices. Thus, the topic of
"Bioresorbable Biomaterials" generates much interest and research
activity in the field of biomaterials science today. For this
reason, the use of bioresorbable polymers as fibers is currently
dominating the field of resorbable biomaterials for applications
from sutures to tissue engineering scaffolds.
Drawing a picture of the current situation of this new field, this
volume both summarizes the past achievements and analyzes the
present unsolved problems.
This book contains the proceedings of the Symposium on FT-IR
Characterization of Polymers, which was held under the auspices of
the Division of Polymer Chemistry, American Chemical Society (ACS)
during the annual ACS meeting in Philadelphia, August, 1984. The
content of each paper has been substantially extended from the
papers presented during the conference. Due to the accidental,
irrecoverable loss of the entire contents of the book by the
computer system used for editorial purposes, the publication of
this book has been delayed more than one year over the initial
scheduled date. It has been a continuous, frustrating experience
for the editor as well as for the authors. An extended Murphy's
law, -anything can go wrong goes multiply wrong- has been
demonstrated in editor's office. It necessitated, otherwise
unnecessary, repeated proof reading during which time the editor
had valuable experience ~n familiarizing himself with each paper
much more than usual. The papers in this book are state-of-the-art
even after such a delay. It is the authors pride and integrity
toward the quality of each paper that makes the value of this book
long lasting, while responsibility of the loss of any timeliness
rests at the editor's hand. For the purpose of official records,
submission and acceptance dates must be stated. All papers had been
submitted by September, 1984, and had been accepted for publication
by November, 1984, after the critical review processes.
This book is concerned with the configuration of polymers at the
interfacial zone between two other phases or immiscible components.
In recent years, developments in technology combined with increased
attention from specialists in a wide range of fields have resulted
in a considerable increase in our understanding of the behavior of
polymers at interfaces. Inevitably these advances have generated a
wealth of literature and although there have been numerous reviews,
a critical treatment with adequate descriptions of both theory and
experiment, including detailed analysis of the two, has been
missing. This text hopes to fill this gap, providing a timely and
comprehensive account of the field as it stands today. This long
needed work will be invaluable to experts as well as newcomers in
the broad field of polymers, interfaces and colloids, both in
industry and academia. Whilst industrial laboratories involved in
this field will find it indispensable, it will be equally important
to anyone with an interest in interfacial polymer or colloidal
research.
In recent years, a growing number of engineering applications of
light weight and energy efficient plastics can be found in high
quality parts vital to the func tioning of entire equipments and
structures. Improved mechanical properties, especially balance of
stiffness and toughness, are among the most frequently desired
features of the new materials. In addition, reduced flammability is
con sidered the single most important requirement for further
expansion of plastics into large volume and demanding markets such
as construction and mass trans port. Production of power cables
also requires flame retardant cable jacketing plastics to replace
or at least to reduce consumption of environmentally unsound PVC.
The two principal ways to achieve the goals mentioned above include
the development of completely new thermoplastic polymers and
various modifica tions of the existing ones. Development and
commercialization of a new ther moplastic require mobilization of
large human and financial resources, the lat ter being within the
range from $100 million to $10 billion, in comparison to $100
thousand to $10 million needed to develop and commercialize
polymeric mate rial with prescribed end use properties using
physical or chemical modification of an existing plastic. In
addition, the various markets utilizing thermoplastics demand large
flexibility in material properties with only moderate volumes, at
the best.
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