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Book Block Polymers

Download or read book Block Polymers written by American Chemical Society. Meeting and published by . This book was released on 1970 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Block Polymers

Download or read book Block Polymers written by S. L. Aggarwal and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block polymers represent another milestone in the preparation of polymers of controlled structure. Catalysts and polymerization methods that allowed the preparation of polymers in which the stereo- and geometric isomerism of the monomer units could be con trolled have indeed been among the major developments in polymer science during the last decade. The synthesis of block polymers, in which the sequence length of the comonomer units can be con trolled, portends equally important developments in the science and technology of polymers. The papers collected in this volume cover primarily the pro ceedings of the most recent symposium on block polymers, sponsored by the Division of Polymer Chemistry of the American Chemical Society. It was held in New York City during the Society's 158th National Meeting in September, 1969. Additional contributions from selected authors were invited especially for this book to achieve the most up-to-date account of the advances that have been made since the development of the thermoplastic elastomers that first brought into focus this important area of research. The first two papers in this volume draw attention to the various problems that should be considered in the preparation of block polymers of precisely defined structure from styrene and butadiene or isoprene by anionic polymerization. Characterization of block polymers presents many problems and there is a paucity of systematic work in this area. Attention has been given to the di lute solution properties of block polymers,however, in one of the papers in this volume.

Book Synthesis and Characterization of Poly propylene Fumarate Oligomers Via a Chain growth Mechanism for Continuous Digital Light Processing CDLP

Download or read book Synthesis and Characterization of Poly propylene Fumarate Oligomers Via a Chain growth Mechanism for Continuous Digital Light Processing CDLP written by Yuanyuan Luo and published by . This book was released on 2015 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an unmet demand in bone-tissue engineering to find new materials for the treatment of orthopedic injuries. More than 6.3 million fractures occurred in the United States in 2003 and around 1 million needed hospitalizations.1 More than 36 million Americans suffer from arthritis.2 Biodegradable synthetic polymers have many advantages over other materials for bone-tissue engineering. One of the most important advantages is that the mechanical properties and degradation kinetics can be tailored to meet different clinical requirements.3 Poly(lactic acid), poly(glycolic acid) and their copolymers have been used extensively in surgical sutures.3 Polyesters are also used in tissue-engineering applications because their non-toxic degradation products generated through hydrolytic degradation are absorbed readily through metabolic pathways.4 Poly(propylene fumarate) (PPF) is an unsaturated linear, biodegradable, synthetic polyester that can be crosslinked through its double bond. Three dimensional (3D) printed PPF is an attractive candidate for bone tissue engineering due to high mechanical strength and controlled porosity of the scaffold for bone in-growth.5 During the last three decades, there have been many studies on PPF as a biodegradable bone cement.6 However, the traditional method to synthesize PPF using a step-growth polymerization requires high energy input, long reaction time with high molecular mass distribution, uncontrolled isomerization or cross-linking.7−8 These factors greatly influence the resulting mechanical properties and degradation rates of the final product, which further hinder studies of PPF-based 3D printed scaffolds on large animal models and pilot human clinical trials. To further improve the properties of PPF, a mild catalytic chain-growth mechanism was used in this study.9−10 The goal of this project is to synthesize PPF oligomers with well-defined properties to improve applications of PPF in bone tissue engineering. Kinetics studies on PPF oligomer synthesis by the copolymerization of maleic anhydride and propylene oxide with magnesium ethoxide as initiator were performed. Then, PPF oligomers at five number-average molecular weights (Mn) (700 Da, 1270 Da, 1860 Da, 2450 Da, 3160 Da) were synthesized. The chemical structures and molecular mass properties of these PPF oligomers were characterized and confirmed by nuclear magnetic resonance proton spectroscopy (1H NMR), nuclear magnetic resonance carbon spectroscopy (13C NMR), matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer, Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectrophotometer (UV-Vis). Differential scanning calorimetry (DSC) was used to detect the glass transition temperature of PPF samples. Intrinsic viscosities of PPF samples at five molecular mass levels were obtained in THF using an Ubbelohde viscometer.

Book Ring opening Polymerization

Download or read book Ring opening Polymerization written by James E. McGrath and published by . This book was released on 1985 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Polymer Functionalized Graphene

Download or read book Polymer Functionalized Graphene written by Arun Kumar Nandi and published by Royal Society of Chemistry. This book was released on 2021-06-18 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is an immense variety of research on polymer functionalized graphene (PFG). Functionalization of graphene is necessary for improvement of the compatibility with polymers. Applications of these graphene polymer hybrids include in chemical and biological sensing, photovoltaic devices, supercapacitors and batteries, dielectric materials and drug/gene delivery vehicles. This book will shed light on the synthesis, properties and applications of these new materials, covering two methods (covalent and noncovalent) for producing polymer functionalized graphene. Chapters cover physical, optical, mechanical and electronic properties, applications of polymer functionalized graphene in energy harvesting and storage, and uses in biomedicine and bioengineering. Written by an expert in the field, Polymer Functionalized Graphene will be of interest to graduate students and researchers in polymer chemistry and nanoscience.

Book Oligomer Technology and Applications

Download or read book Oligomer Technology and Applications written by Uglea and published by CRC Press. This book was released on 1998-01-05 with total page 1025 pages. Available in PDF, EPUB and Kindle. Book excerpt: Details laboratory and industrial synthesis and applications of oligomers-suggesting practical solutions to the on-the-job problems as well as exploring processing devices and techniques for industrial-scale production of new oligomer types.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Book Characterization and Study of Solution Properties of Poly propylene Oxide Synthesized by Metal Xanthate Catalysts

Download or read book Characterization and Study of Solution Properties of Poly propylene Oxide Synthesized by Metal Xanthate Catalysts written by Eylem Tarkın and published by . This book was released on 2003 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis and 3D Printing of Poly propylene Fumarate Derivatives for Biomedical Applications

Download or read book Synthesis and 3D Printing of Poly propylene Fumarate Derivatives for Biomedical Applications written by Yongjun Shin and published by . This book was released on 2021 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additive manufacturing, also known as 3D printing, is driving new frontiers in regenerative medicine due to its ability to fabricate patient and defect specific devices. In particular, continuous digital light processing (cDLP) photochemically cures all pixels in one layer simultaneously, and therefore build speeds are greatly increased compared to other additive manufacturing methods. Continuous liquid interface production (CLIP) reduces the build time further by adapting oxygen inhibition layer which removing delamination step. However, despite the rapid development of 3D printing technology, a lack of diversity in printable materials significantly limits the use of 3D printing as a common biofabrication technique in medicine. Poly(propylene fumarate) (PPF) is a bioresorbable polyester that can be printed using stereolithographic processes, making it a promising candidate for tissue engineering applications. However, the high viscosity of PPF necessitates the addition of an equal weight of diethyl fumarate (DEF) as a reactive diluent in resin formulations to ensure the 3D printability. Moreover, the brittle nature of the resulting 3D printed product, formation of non-biodegradable bond, and long fabrication time hinder application of PPF to broad tissue engineering fields.In this study, a ring-opening copolymerization (ROCOP) of propylene oxide with saturated and unsaturated anhydrides using a Mg(BHT)2(THF)2 catalyst followed by isomerization yields poly(propylene fumarate) (PPF) derivatives in gradient and block architectures. The resulting copolymers have well-defined molecular masses, narrow molecular mass distributions, quantitative end-group fidelity, and a reduced viscosity compared to traditional PPF. Mass spectrometry analysis, NMR spectroscopy, and kinetic studies verify the architecture of the resulting copolymers. The lower viscosity of the statistical copolymers affords 3D printability with a lower diluent fraction (30 wt.%) and higher molecular mass copolymer in the resin formulations. Additionally, the use of thiol-ene click chemistry in the printing process is demonstrated to provide dramatically lower printing times and fabrication of fully degradable networks. We also show the mechanical properties of the printed structures are diverse (0.5 to 200 MPa in E0 and 10 to 380 % in [epsilon]Break) and can be tailored according to polymer architecture, the monomer composition, and resin formulation.

Book Amphiphilic Block Copolymers

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.

Book The Synthesis and Properties of Tetrahydrofurandiyl containing Polymers

Download or read book The Synthesis and Properties of Tetrahydrofurandiyl containing Polymers written by Roice Wille and published by . This book was released on 1987 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: