Download or read book Synthesis of Side chain Liquid Crystalline Polysilane Copolymers written by Ayşe Özge Kuruoğlu and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Hydrogen bonded Side Chain Liquid Crystalline Block Copolymer written by Chi-Yang Chao and published by . This book was released on 2003 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Copolymers written by Yasemin Yüksel Durmaz and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Side chain Liquid Crystal Polymers by Cyclopolymerisation written by Peter Buxton and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Platform of Functional Liquid Crystalline Copolymers Synthesis Morphology Properties and Applications written by Dennis Ndaya and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of novel, complex and tailored macromolecules that present and combine unique features such as stimuli responsive, self-assembly and hierarchical architectures for applications in fields ranging from healthcare, energy to engineering, is one of the major challenges that need to be addressed by a polymer chemist. One way to address this, is through the combination of monomers with desirable roles such as stimuli responsive (liquid crystalline), solubility (polar or non-polar), targeting and payload release functional monomers. Polymerization techniques such as controlled and living polymerization enables the regulation of the connectivity and composition of these diverse monomers in the synthesis of block, random or gradient copolymers. Ring-opening metathesis polymerization (ROMP) majorly employed in most of the work in this thesis, is a robust living polymerization technique which delivers highly functionalized block or random copolymers that serves as nanotemplates (chapter 2), nanoporous membranes for separation (chapter 3), photonic crystals (chapter 4), shape memory devices (chapter 5), stimuli responsive optical materials (chapter 6), drug delivery vehicles and imaging agents (chapter 7). This dissertation focuses on a new platform for the synthesis of novel liquid crystalline polymers, their architectures, morphologies, properties and applications. The control of composition and polymer architecture is key in tuning the properties of copolymers for desired applications. Side-chain Liquid Crystalline Copolymers (SCLPs) which combines the basic properties of conventional polymers and liquid crystals, exhibit low viscosity, unique self-assembly as compared to linear copolymer counterparts due to reduced entanglements. Liquid crystalline block copolymers (LCBCPs) that comprises of brush-like semicrystalline or amorphous units and comblike side chain liquid crystalline moieties will be the center of focus in this dissertation in chapter 2, chapter 4 and part of chapter 7 due to formation of hierarchical structures as a result of two competing processes: (a) microphase separation by the copolymer superstructure and (b) orientational ordering by liquid crystalline mesogens. This supramolecular cooperative assembly leads into a well-defined interface with liquid crystalline ordering in the range of 3 -10nm nanostructures and block microphase segregation of 10- 100nm microstructures. The first part of this dissertation focuses on the understanding of liquid crystalline brush-like block copolymers self-assembly, phase behavior and morphology as a function of copolymer composition and molecular weight. Here, I describe the synthesis and characterization of norbornene functionalized side chain liquid crystalline brush-like block copolymers, where one of the blocks comprises of cyanobiphenyl liquid crystalline mesogens with twelve methylene spacer and the other semi-crystalline polylactide (PLA) side chains. The self-assembly of these LC block copolymers into liquid crystalline mesophase provides the handle for magnetic alignment of the formed LCBBCs superstructures (chapter 7). The displayed morphologies such as hexagonally packed PLA cylinders in the LC matrix is put into use in the creation of functional nanoporous membranes for water purification and heavy metal sequestering (chapter 3). The high molecular weight of this LCBBCs assemble into photonic crystals of large domain sizes with different optical properties (chapter 4). In the second part of the dissertation we explore harnessing of stimuli responsive functional cholesteric random copolymers for multifunctional elastomeric platform and optical materials that cover a wide range from visible to near infrared (NIR) of electromagnetic spectrum. Overall, understanding the structure-properties of these liquid crystalline polymers leads to various applications such as membranes for separation, optics, sensors and drug delivery.
Download or read book Molecular Design Synthesis Characterization and Processing of Liquid Crystalline Diblock Copolymers written by Guoping Mao 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 Liquid Crystalline Polymer Systems written by Avraam I. Isayev and published by . This book was released on 1996 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive report on the synthesis, structure, rheology, processing, performance, and applications of liquid-crystalline polymers (LCPs). Discusses self-reinforced composites prepared through the melt processing of thermoplastics and thermotropic LCPs. Addresses current research efforts in making polymer-dispersed liquid crystals. Reports recent studies on the structure and phase behavior of mesophases. Describes the synthesis and properties of new main-chain and side-chain liquid-crystalline block copolymers, mesogen-jacketed LCPs, and liquid-crystalline thermosets.
Download or read book Molecular Engineering of Liquid Crystalline Polymers by Living Polymerization 20 Synthesis and Characterization of Binary Copolymers of 11 4 Cyano 4 biphenyl Oxy undecanyl Vinyl Ether with N Butyl Vinyl Ether and of 2 4 Cyano 4 biphenyl oxy ethyl Vinyl Ether with N Butyl Vinyl Ether written by and published by . This book was released on 1992 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Copolymerization represents the simplest synthetic technique which can be used to tailor make phase transitions of both main chain and side chain liquid crystalline polymers. Indeed, copolymerization was frequently employed to manipulate the phase transitions of side chain liquid crystalline polymers. However, most of the results reported in the literature can be considered only in a qualitative way, since there are only very few cases in which information about both copolymer composition and molecular weight are available. A general classification of side chain liquid crystalline copolymers was recently discussed in a review article. There are two main classes of side chain liquid crystalline copolymers. The first one refers to copolymers containing pairs of structural units with and without mesogenic units. The second class refers to copolymers based on pairs of structural units containing mesogenic units in each structural unit.
Download or read book Synthesis and Characterization of Polystyrene Polysiloxane Side Chain Liquid Crystalline Diblock Copolymers written by Aaron J. Moment and published by . This book was released on 1998 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 and Characterization of New Systems of Side chain Liquid Crystalline Polymers and Orientation Studies microform written by Guoxiong Yuan and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1997 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molecular Engineering of Liquid Crystal Polymers by Living Polymerization 14 Synthesis and Characterization of Binary Copolymers of Omega 4 Cyano 4 Biphenyl oxyAlkyl Vinyl Ethers Containing Undecanyl and Hexyl Pentyl and Propyl and Undecanyl and Propyl Pairs of Alkyl Groups written by and published by . This book was released on 1991 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Copolymerization represents the simplest synthetic technique which can be used to tailor make phase transitions of both main chain and side chain liquid crystalline polymers. Indeed, copolymerization was frequently employed to manipulate the phase transitions of side chain liquid crystalline polymers. However, most of the results reported in the literature can be considered only in a qualitative way, since there are only very few cases in which information about both copolymer composition and molecular weight are available. A general classification of side chain liquid crystalline copolymers was recently discussed in a review article. There are two main classes of side chain liquid crystalline copolymers. The first one refers to copolymers containing pairs of structural units with and without mesogenic units. This class of copolymers was extensively investigated. The second class refers to copolymers based on pairs of structural units containing mesogenic units in each one.
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 The Synthesis and Characterization of Polystyrene Liquid Crystalline Siloxane Block Copolymers written by Aaron J. Moment and published by . This book was released on 2000 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Physical Properties of Liquid Crystalline Alkylisocyanate Copolymers written by B. Durairaj and published by . This book was released on 1989 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid crystalline copolymer containing 50:50 mole ratios of undecylisocyanate with propyl, butyl, hexyl, and octylisocyanate were synthesized and characterized. By making copolymers, the temperature range of isotropic state (i.e. range between the clearing and decomposition temperatures) was increased over that for poly (undecylisocyanate). The results from various analyses showed that all the copolymers undergo decomposition at 180 C. The dependence of Tg on alkyl side chain length and copolymer composition was consistent with that for other alkyl-side-chain polymers. Liquid crystalline polymers. (mjm).
