Download or read book Synthesis and Characterization of Star branched Polymers written by Allison Marolen Sikes and published by . This book was released on 1988 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Hetero Three arm Star branched Polymers Via Macromonomers written by Hong Dixon and published by . This book was released on 1996 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Polyisobutylene Based Multi arm Star branched Polymers Via Living Carbocationic Polymerization written by Mary Kelly Anderson Shoemake and published by . This book was released on 1997 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Miktoarm Star Polymers written by Ashok Kakkar and published by Royal Society of Chemistry. This book was released on 2017-04-13 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term ‘miktoarm polymers’ refers to asymmetric branched macromolecules, a relatively new entry to the macromolecular field. Recent advances in their synthesis and intriguing supramolecular chemistry in a desired medium has seen a fast expansion of their applications. The composition of miktoarm polymers can be tailored and even pre-defined to allow a desired combination of functions, meaning polymer chemists can have complete control of the overall architecture of these macromolecules. By carefully selecting the composition, they can create supramolecular structures with intriguing properties, particularly for applications in biology. Miktoarm Star Polymers features chapters from experts actively working in this field, and provides the reader with a unique introduction to the fundamental principles of this exciting macromolecular system. Topics covered include the design, synthesis, characterization, self-assembly and applications of miktoarm polymers. The book is an excellent overview and up to date guide to those working in research in polymer chemistry, materials science, and polymers for medical applications.
Download or read book Complex Macromolecular Architectures written by Nikos Hadjichristidis and published by John Wiley & Sons. This book was released on 2011-04-20 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of CMA (complex macromolecular architecture) stands at the cutting edge of materials science, and has been a locus of intense research activity in recent years. This book gives an extensive description of the synthesis, characterization, and self-assembly of recently-developed advanced architectural materials with a number of potential applications. The architectural polymers, including bio-conjugated hybrid polymers with poly(amino acid)s and gluco-polymers, star-branched and dendrimer-like hyperbranched polymers, cyclic polymers, dendrigraft polymers, rod-coil and helix-coil block copolymers, are introduced chapter by chapter in the book. In particular, the book also emphasizes the topic of synthetic breakthroughs by living/controlled polymerization since 2000. Furthermore, renowned authors contribute on special topics such as helical polyisocyanates, metallopolymers, stereospecific polymers, hydrogen-bonded supramolecular polymers, conjugated polymers, and polyrotaxanes, which have attracted considerable interest as novel polymer materials with potential future applications. In addition, recent advances in reactive blending achieved with well-defined end-functionalized polymers are discussed from an industrial point of view. Topics on polymer-based nanotechnologies, including self-assembled architectures and suprastructures, nano-structured materials and devices, nanofabrication, surface nanostructures, and their AFM imaging analysis of hetero-phased polymers are also included. Provides comprehensive coverage of recently developed advanced architectural materials Covers hot new areas such as: click chemistry; chain walking; polyhomologation; ADMET Edited by highly regarded scientists in the field Contains contributions from 26 leading experts from Europe, North America, and Asia Researchers in academia and industry specializing in polymer chemistry will find this book to be an ideal survey of the most recent advances in the area. The book is also suitable as supplementary reading for students enrolled in Polymer Synthetic Chemistry, Polymer Synthesis, Polymer Design, Advanced Polymer Chemistry, Soft Matter Science, and Materials Science courses. Color versions of selected figures can be found at www.wiley.com/go/hadjichristidis
Download or read book Miktoarm Star Polymers written by Ashok Kakkar and published by Royal Society of Chemistry. This book was released on 2017-04-20 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a detailed monograph on the topic, this book features chapters from experts actively working in this field, and is intended to provide the reader with a unique overview of the fundamental principles of this exciting macromolecular platform.
Download or read book Star and Hyperbranched Polymers written by Munmaya Mishra and published by CRC Press. This book was released on 1999-05-25 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesizing the raw data needed for a wide variety of industrial applications, this work supplies up-to-date advanced in research on star, hyperbranched and dendritic polymers. It provides detailed descriptions of the size and shape of the molecules that make up these polymers, as well as their biological advances, low viscosity in solution and substrate-holding properties.
Download or read book Synthesis and Characterization of Branched Polyelectrolytes written by Daniel Wade Holley and published by . This book was released on 2009 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, we examined the effect of branching on the solution characteristics of polyelectrolytes using a set of star-branched NaPSS. The polystyrene precursors to these polyelectrolytes were synthesized using anionic polymerization allowing for the production of three distinct groups of star-branched polystyrenes with varying functionality and arm length. Following sulfonation, several methods commonly employed in the literature for evaluation of sulfonation degree we established that sulfonation was quantitative. TGA was also demonstrated to reveal important characteristics of the sample. We used aqueous SEC coupled with a multiple angle light scattering detector to determine several molecular characteristics of the star-branched NaPSS samples. Linear NaPSS synthesized via radical polymerization and sulfonation of polystyrene were characterized and important differences between NaPSS synthesized by the two methods were established. Dynamic light scattering experiments established a qualitative link between the presence of a slow diffusive mode and the degree of sulfonation. The branching parameter g was determined for the star-branched NaPSS samples and compared to theoretical predictions. Static light scattering experiments were performed to elucidate the effect of C[Subscript s] on the R[Subscript g], where it was determined that R[Subscript g] ~ C[Subscript s][Superscript -0.11] for the whole range of samples. The apparent persistence length was determined and relations were established for its variation as a function of C[Subscript s], f and degree of arm polymerization. Additionally, no agreement was found between theoretical predictions of g and experimentally determined ones. A method was developed that enabled the determination of molecular dimensions of star-branched NaPSS using AFM with a high degree of agreement with the radii established using scattering methods on solutions of the polymers. The intrinsic viscosity could reliably be determined in solutions with C[Subscript s] using either a Huggins or Wolf equation. For solutions with no C[Subscript s], the Huggins equation fit over the data at low C[Subscript p] was confirmed by AFM measurements of the dimensions of the polyelectrolyte and comparisons to the radius determined from the intrinsic viscosities calculated using the two equations to be more accurate. The values of g' were calculated for solutions of the NaPSS stars in water and compared with theory.
Download or read book Synthesis and Characterization of Bis MPA Based Branched Polymers with Thymine Core written by Elena Zelentsova and published by . This book was released on 2009 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Branched Polymers I written by Jaques Roovers and published by Springer. This book was released on 2003-07-01 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: While books have been written on many topics of Polymer Science, no compre hensive treatise on long chain branching has ever been composed. This series of reviews in Volume 142 and 143 of Advances in Polymer Science tries to fill this gap by highlighting active areas of research on branched polymers. Long chain branching is a phenomenon observed in synthetic polymers and in some natural polysaccharides. It has long been recognized as a major mole cular parameter of macromolecules. Its presence was first surmised by H. Stau dinger and G. V. Schuh (Ber. 68, 2320, 1935). Interestingly, their method of iden tification by means of the abnormal relation between intrinsic viscosity and molecular weight has survived to this day. Indeed, the most sophisticated method for analysis of long chain branching uses size exclusion fractionation with the simultaneous recording of mass, molecular weight and intrinsic visco sity of the fractions. In the 1940s and 1950s, random branching in polymers and its effect on their properties was studied by Stockmayer, Flory, Zimm and many others. Their work remains a milestone on the subject to this day. Flory dedicated several chapters of his "Principles of Polymer Chemistry" to non linear polymers. Especially important at that time was the view that randomly branched polymers are inter mediates to polymeric networks. Further developments in randomly branched polymers came from the introduction of percolation theory. The modern aspec ts of this topic are elaborated here in the chapter by W. Burchard.
Download or read book Synthesis Characterization and Viscometric Studies of Linear and Star Branched Polydimethylsiloxane Polymers written by Matthew J. Kampling and published by . This book was released on 1987 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Complex Polymer Architectures written by Brandon Scott Farmer and published by . This book was released on 2006 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anionic polymerization based upon high vacuum technique has been used to synthesize different star polymers using varying linking techniques. In particular chlorosilanes, divinylbenzene, and polyhedral oligomeric silsesquioxane (POSS) chlorosilane derivatives were used in the synthesis of star polymers. These polymers, along with polymers synthesized by others, have been characterized by a range of methods in this work.
Download or read book Controlled Synthesis and Characterization of Branched Functionalized and Cyclic Polymers written by Vijay Chavan and published by . This book was released on 2011 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of methods were used to make polymers with different architecture and functionalities. The linking chemistry of vinyldimethylchlorosilane (VDMCS) with poly(styryl)lithium (M[subscript n] = 1,700-3,000 g/mol) was studied. The average degree of branching varied from 7.5 to 9.4 with an increase in concentration of VDMCS (1.2 to 5.2 eq). The intrinsic viscosities and melt viscosities (at 160°C) of the star polymers were found to be less than half of that of the corresponding linear polystyrenes. [alpha]-Pyrrolidine-functionalized polystyrene (M[subscript n] = 2,700 g/mol, M[subscript w]/M[subscript n] = 1.03, 92.5%) was successfully synthesized from [alpha]-chloromethyldimethylsilane-functionalized polystyrene (M[subscript n] = 2,600 g/mol, M[subscript w]/M[subscript n] = 1.02) based on NMR spectroscopy, MALDI-TOF and ESI mass spectrometry. The stability of silyl hydride groups under atom transfer radical polymerization conditions was proven by copolymerizing methyl methacrylate and (4-vinylphenyl)dimethylsilane (VPDS). Tapered block copolymers of isoprene, VPDS, and styrene with narrow molecular weight distributions (1.04 and 1.05) were synthesized via anionic polymerization. Evidence regarding the topology of cyclic polybutadienes was obtained by Atomic Force Microscopy of grafted polymers obtained by grafting an excess of silyl hydride-functionalized polystyrene (M[subscript n] = 8,300 g/mol, M[subscript w]/M[subscript n] =1.01) onto cyclic polybutadiene (M[subscript n]=88,000 g/mol, M[subscript w]/M[subscript n] = 2.0). The reactivity of polyisobutylene carbocations was compared with respect to competitive electrophilic addition to a vinyl group versus silyl hydride transfer by investigating the reaction with VPDS. Based on GPC results, and 1H and 13C NMR spectroscopy, no evidence for any vinyl group addition was observed. A successful attempt was made to prepare electrospun fibers from fluoro-functionalized styrene-butadiene elastomers. The water contact angle of these surfaces was found to be 162.8° [plus or minus] 3.8° for the fibrous mat of the fluorinated polymers as compared to 151.2° [plus or minus] 2.4° for the analogous fibrous mat of the non-fluorinated polymers. In-chain functionalization of tapered styrene butadiene rubber using chloromethydimethylsilane was quantitatively done via a hydrosilation reaction. Pyrrolidine-functionalized styrene butadiene rubber was obtained in 71% yield after reacting pyrrolidine with chloromethyldimethylsilane-functionalized styrene butadiene rubber. In-chain, silyl hydride-functionalized, deuterated polystyrene (M[subscript n] = 2,100 g/mol, M[subscript w]/M[subscript n] = 1.01) was functionalized with allyl cyanide in the presence of Karstedt's catalyst to obtain in-chain cyano-functionalized, deuterated polystyrene (45% based on the mass of in-chain, cyano-functionalized deuterated polystyrene obtained).
Download or read book Synthesis of Polymers written by Dieter A. Schlüter and published by John Wiley & Sons. This book was released on 2012-05-23 with total page 1229 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are huge macromolecules composed of repeating structural units. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials. Due to the extraordinary range of properties accessible, polymers have come to play an essential and ubiquitous role in everyday life - from plastics and elastomers on the one hand to natural biopolymers such as DNA and proteins on the other hand. The study of polymer science begins with understanding the methods in which these materials are synthesized. Polymer synthesis is a complex procedure and can take place in a variety of ways. This book brings together the "Who is who" of polymer science to give the readers an overview of the large field of polymer synthesis. It is a one-stop reference and a must-have for all Chemists, Polymer Chemists, Chemists in Industry, and Materials Scientists.
Download or read book The Synthesis and Characterization of Model Linear and Star branched Polycaprolactones written by Margarita Beltran Sori and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anionic Synthesis of Heteroarm Star branched Polymers written by Taejun Yoo and published by . This book was released on 1994 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anionic Synthesis of Well defined Functionalized and Star branched Polymers written by Manuela Ocampo and published by . This book was released on 2007 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel methods for the synthesis of chain-end and in-chain functionalized polymers, as well as star polymers, were developed using anionic polymerization techniques. A new mechanism for the reaction of polymeric organolithium compounds with thiiranes has been found. The reaction of poly(styryl)lithium and poly(butadienyl)lithium with propylene sulfide and ethylene sulfide was investigated in hydrocarbon solution for the preparation of thiol-functional polymers. It was found by MALDI-TOF mass spectral analysis of the reaction products that the reaction proceeded by attack of the anion on the methylene carbon atom of the thiirane ring followed by ring opening to form the thiol-functionalized polymer. The reaction of poly(styryl)lithium with trimethylene sulfide did not produce the corresponding thiol-functionalized polymer; the resulting methyl-terminated polymer was formed by attack of the anion on the sulfur atom followed by ring opening to form a primary carbanion. A new method for synthesis of alkoxysilyl-functionalized polymers was developed. Using a general functionalization methodology based on the hydrosilation of vinyltrimethoxysilane with [omega]-silyl hydride-functionalized polystyrene, alkoxysilyl-functionalized polystyrene was obtained in high yield (83 %). The main side product was vinylsilane-functionalized polymer. A small amount of dimer (approximately 2 %) was formed from the hydrosilation reaction of silyl hydride-functionalized polymer and vinylsilane-functionalized polymer. Star polymers with an average number of 6.8 arms were obtained by reacting poly(styryl)lithium with 6.6 equivalents of vinyldimethylchlorosilane in benzene at 30 °C. It was found that, in benzene at 30 °C, vinyldimethylchlorosilane is an efficient linking agent for the preparation of well-defined star-branched polymers. In contrast, the reaction of poly(styryl)lithium with 5 equivalents of vinyldimethylchlorosilane in THF at -78 °C produced vinylsilane-functionalized polymer in high yield (> 93 %). Poly(styryl)lithium was reacted with 2.5 equivalents of vinyldimethylethoxysilane; reaction occurred exclusively by the addition of the living anion to the vinyl group. In-chain, dihydroxyl-functionalized polystyrene was prepared by reaction of poly(styryl)lithium and 1,3-butadiene diepoxide. The hydroxyl functionalities were activated with potassium naphthalenide. Addition of ethylene oxide monomer yielded the corresponding heteroarm polystyrene/poly(ethylene oxide) stars. Two commercially available triepoxides, N,N-diglycidyl-4-glycidyloxyaniline and Tactix 742, were used to prepare the corresponding 3-armed stars in high yield.
