Download or read book Synthesis of Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization 1 Influence of Molecular Weight Polydispersity and Flexible Spacer Length n written by and published by . This book was released on 1992 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The living ring opening metathesis polymerization of 5-carbo(n-(4'- methoxy-4-biphenylyl)oxy)alkyl)bicyclo(2.2.1)hept-2-ene (1-n, n=2-8) by Mo(CH-t- Bu)(NAr) (0-t-Bu)2(Ar=2,6-C6H3-t-Pr2) is described. Polymers with degrees of polymerization from 5 to 100 and narrow molecular weight distributions (Mw/Mn=1. 05-1.24) were obtained in high yield. All polymers exhibit an enantiomorphic nematic mesophase. Glass transition and isotropization temperatures increase with increasing molecular weight and become independent at approximately 30-50 repeat units. The change in enthalpy of isotropization is relatively independent of molecular weight. Using polymer blends, it was shown that polydispersity has no effect on either the transition temperatures or the temperature range of isotropization. Isotropization alternates in an odd-even manner up to spacer lengths of n=6, and then levels off. Living ring opening metathesis polymerization, Side chain liquid crystalline polymers (SCLCPs).

Download or read book Synthesis of Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization 2 Influence of Molecular Weight Polydispersity and Flexible Spacer Length n written by and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The living ring opening metathesis polymerization of 5-carbo(n-(4'- METHOXY-4BIPHENYLYLoxyalkyl)bicylco2.2.1hept-2-ene (1-n, n=9-12) with Mo(CH-t- Bu)(NAr) (0-t-Bu)2 (Ar=2,6-C6H3-i-Pr2) is described. Polymers with degrees of polymerization from 5 to 100 and narrow molecular weight distributions (Mw/Mn=1. 07-1.28) were obtained in high yield. All polymers exhibit side chain crystallization along with a nematic mesophase. Isotropization temperatures increase with increasing molecular weight and then become independent of molecular weight at approximately 30-50 repeat units. Side chain crystallization is suppressed as molecular weight increases.

Download or read book Synthesis of Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization 3 Influence of Molecular Weight Interconnecting Unit and Substituent on the Mesomorphic Behavior of Polymers with Laterally Attached Mesogens written by and published by . This book was released on 1992 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Norbornene derivatives containing laterally attached 2,5-bis(4'-n- alkoxybenzoyl OXY) mesogens were polymerized by controlled ring opening metathesis polymerization to provide polymers in high yield with 5-100 repeat units and narrow molecular weight distributions. Monomers with n>l displayed monotropic or enantiotropic nematic mesophases. All polymers displayed enantiotropic nematic mesophases regardless of the spacer, molecular weight or length or the n-alkoxy substituent. Constitutional isomers of poly(5-carbo(2', 5'-bis-4(methoxybenzoyloxy)benzyloxy)bicyclo(2.2.1)hep t-2-ene)s containing laterally attached mixed phenylester/benzylester units are amorphous. Side chain liquid crystal polymers (SCLCPs), living ring opening metathesis polymerization.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization 5 Influence of Mesogenic Group and Interconnecting Group on the Thermotropic Behavior of the Resulting Polymers written by and published by . This book was released on 1992 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Norbornene derivatives containing 4'-cyano-4-biphenyloxy mesogens linked to the norbornene through methylene groups (n = 3-7, 9-12) and an ester were polymerized by Mo(CHR)(NAr)(O-t-Bu)2 (Ar = 2,6-C6H3-i-Pr2, R = t-Bu) in a living manner. Polymers in which n = 3 were amorphous, whereas all other polymers (n = 4-7, 9-12) displayed enantiotropic nematic mesophases that were independent of the molecular weight. Polymers having 9-12 methylene spacers did not undergo side chain crystallization and did not show an odd-even effect, in contrast to analogous polymers containing 4'-methoxy-4-biphenyloxy mesogens, which exhibited side chain crystallization when n> 8 and an odd-even effect when n

Download or read book Synthesis of Side Chain Liquid Crystal Polymers by Living Ring Opening Metathesis Polymerization 4 Synthesis of Amorphous and Side Chain Liquid Crystal AB Block Copolymers written by and published by . This book was released on 1992 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diblock copolymers with well defined block length yield ordered phase separation. Morphology of the microphase separation is controllable by varying the weight ratio of the two blocks and the length of each block. If one of the blocks is a side chain liquid crystalline polymer (SCLCP), microphase separated systems with liquid crystalline microphases may be realized. Such systems are of fundamental as well as practical interest. The effect of size and type of the liquid crystalline microphase transition is one of the fundamental questions. This effect is recently investigated by the polymer system in which low molecular weight liquid crystals are dispersed. Different from the low molecular weight liquid crystals dispersed systems, the block copolymer can give several types of microdomains (lamellae, cylinders, or spheres).

Download or read book Liquid Crystal Polymers written by D. Coates and published by iSmithers Rapra Publishing. This book was released on 2000 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid crystal polymers (LCPs) have a wide range of uses, from strong engineering plastics to delicate gels for use in liquid crystal (LC) displays. For this reason, it is essential reading for materials scientists, engineers or technologists in industry, as well as research laboratories or academia. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992-08 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Engineering Index Annual written by and published by . This book was released on 1992 with total page 2264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its creation in 1884, Engineering Index has covered virtually every major engineering innovation from around the world. It serves as the historical record of virtually every major engineering innovation of the 20th century. Recent content is a vital resource for current awareness, new production information, technological forecasting and competitive intelligence. The world?s most comprehensive interdisciplinary engineering database, Engineering Index contains over 10.7 million records. Each year, over 500,000 new abstracts are added from over 5,000 scholarly journals, trade magazines, and conference proceedings. Coverage spans over 175 engineering disciplines from over 80 countries. Updated weekly.

Download or read book Synthesis of Polymers written by A.-D. Schlüter and published by Wiley-VCH. This book was released on 1999-05-11 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers find their applications in ever more areas of modern technology. The invention of new synthetic methods allows the polymer chemist to design new polymer materials with specific mechanical, optical or electronic properties . This concise handbook covers all modern synthetic methods in polymer science. It will enable the polymer chemist or materials scientist to find details about the specific synthesis he wants to use in designing polymers with new advanced properties.

Download or read book Research in Materials written by and published by . This book was released on 1993 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2007 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research in Materials written by Massachusetts Institute of Technology and published by . This book was released on 1993 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Transition Metal Polymerization Catalysts written by Ray Hoff and published by John Wiley & Sons. This book was released on 2018-04-20 with total page 895 pages. Available in PDF, EPUB and Kindle. Book excerpt: Including recent advances and historically important catalysts, this book overviews methods for developing and applying polymerization catalysts – dealing with polymerization catalysts that afford commercially acceptable high yields of polymer with respect to catalyst mass or productivity. • Contains the valuable data needed to reproduce syntheses or use the catalyst for new applications • Offers a guide to the design and synthesis of catalysts, and their applications in synthesis of polymers • Includes the information essential for choosing the appropriate reactions to maximize yield of polymer synthesized • Presents new chapters on vanadium catalysts, Ziegler catalysts, laboratory homopolymerization, and copolymerization

Download or read book Liquid Crystalline Polymers written by Lei Zhu and published by Springer. This book was released on 2020-08-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of various self-assemblies in liquid crystalline polymers and their electrical, optical, mechanical, and flame retardant properties. Liquid crystalline polymers are unique self-assembled, functional soft materials with electrical, magnetic, and thermal responses which find potential applications in numerous areas. As well as providing an overview of their synthesis, self-assembly and dynamics the various applications are also discussed. Such applications as liquid crystalline elastomers, light responsive actuators, optical reflectors, gas barrier films, and even flame retardant polymers will be presented. The book is a useful resource for undergraduates, postgraduates and experienced researchers.