Download or read book Liquid Crystalline Polymers Containing Mesogenic Units Based on Half Disc and Rod Like Moieties 5 Side Chain Liquid Crystalline Polymethylsiloxanes Containing Hemiphasmidic Mesogens Based on 4 3 4 5 Tris alkan 1 yloxy Benzoyloxy 4 p propan l yloxy benzoyloxy biphenyl Groups written by and published by . This book was released on 1991 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis of hemiphasmidic monomers 4-(3,4,5-tris(S( - )-2- methylbutan-1-yloxybenzoyloxy -4'-(p-allyloxybenzoyloxy)biphenyl (4), 4-3,4,5- tris(n-pentan-1-yloxy)benzoyloxy-4'-(p-allyloxybenzoyloxy)biphenyl (15), and 4- (3,4,5-tris(n-dodecan-1-yloxy) benzoyloxy-4'-(p-allyloxybenzoyloxy) biphenyl (16) and of the corresponding polymethylsiloxanes (17,18, and 19) is described. Both monomers and polymers were characterized by a combination of differential scanning calorimetry (DSC), WAXS, SAXS, and thermal optical polarized microscopy. 15, 16, and 17 are crystalline. 17 exhibits an enantiotropic double layer smectic A or C mesophase. 18 displays a monotropic columnar hexagonal and an enantiotropic double layer smectic A or C mesophases. Due to its close proximity to the glass transition temperature, the columnar hexagonal phase of 18 is strongly kinetically controlled. 19 exhibits a very broad enantiotropic hexagonal columnar mesophase. The columns of the mesophases of 18 and 19 are generated by an elongated polymer backbone penetrating through the center of the column and tapered extended mesogens radiating out of it.
Download or read book ACS Directory of Graduate Research 1993 written by American Chemical Society. Committee on Professional Training and published by . This book was released on 1993 with total page 1700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1991-10 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Crystalline Polymers Containing Heterocycloalkane Mesogens 1 Side Chain Liquid Crystalline Polymethacrylates and Polycrylates Containing 2 5 Disubstituted 1 3 Dioxane Mesogens written by C. S. Hsu and published by . This book was released on 1986 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymethacrylates and polyacrylates containing 2-(p-hydroxphenyl)-5-(p-methoxyphenyl)-1-, 3-dioxane as a mesogenic unit and an aliphatic spacer containing eleven methylene units were synthesized. Their phase behavior was studied by differential scanning calorimetry and optical polarization microscopy, and compared with the phase behavior of the corresponding polymethacrylates and polyacrylates based on 4-methoxy-4'-hydroxbiphenyl mesogen. All polymers present smectic mesomorphism. The 2,5-disubstituted-1,3-dioxane mesogen resembles a terphenyl mesogen in which the internal phenyl ring was hydrogenated. Even so, when compared with the biphenyl containing polymers, the glass transition temperatures of the 1,3-dioxane containing polymers are lower, although their isotropization occurs at higher temperatures. Keywords: Side-chain thermotropic liquid crystalline polymers.
Download or read book Liquid Crystalline Polymers Containing Heterocycloalkane Mesogens 2 Side Chain Liquid Crystalline Polysiloxanes Containing 2 5 Disubstituted 1 3 Dioxane Mesogens written by C. S. Hsu and published by . This book was released on 1986 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polysiloxanes and copolysiloxanes containing 2-(p-hydroxyphenyl)-5-(p-methoxyphenyl)-1,3-dioxane and 5-(p-methoxyphenyl)-1,3-dioxan-2-yl as mesogenic units and an aliphatic spacer containing eleven and respectively, ten methylene units were synthesized. Their phase behavior was studied by differential scanning calorimetry and optical polarization microscopy, and compared with the phase behavior of the polysiloxanes and copolysiloxanes containing 4-meth-oxy-4'-hydroxybiphenyl and 4-cyano-4'-hydroxybiphenyl mesogens attached to the polymer backbone through an aliphatic spacer containing eleven methylene units. All synthesized polymers present smectic mesomorphism. The polymers containing 4-methoxy-4'-hydroxybiphenyl and 4-cyano-4'-hydroxybephenyl are also crystalline, while the polymers containing 1,3-dioxane based mesogens do not crystallize.
Download or read book Side Chain Liquid Crystal Polymers written by C.B. McArdle and published by Springer Science & Business Media. This book was released on 1990-04-30 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Crystalline Polymers Containing Heterocycloalkane Mesogens Biphasic Side Chain Liquid Crystalline Polysiloxanes Containing Trans 5 n undecanyl 2 4 cyanophenyl 1 3 Dioxane Side Groups written by Chain S. Hsu and published by . This book was released on 1987 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polysiloxanes and copolysiloxanes containing the trans 5-(n-undecanyl)-2-(4-cyanophenyl)-1,3-dioxane side group as mesogen were synthesized. Their phase behavior was studied by differential scanning calorimetry and optical polarization microscopy. Homopolymers containing the mesogen and a copolymer containing 33% of the mesogen showed smectic mesomorphism. The copolymers containing the mesogen showed two well defined Tg and thus present strong evidence for a phase separated morphology.
Download or read book Liquid Crystal Polymers From Structures to Applications written by A.A. Collyer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of liquid crystals and their use in electronic displays and in non-linear optical systems has become of tremendous importance during the last decade; and the incorporation of liquid crystal units into polymeric materials has led to a group of new materials with diverse properties. Some of these properties have been utilized in new products and some have yet to be used. Much published work has appeared that deals with specific materials or particular applications, and it was felt that a book was needed to examine and explain the underlying principles governing the diverse properties of these liquid crystal polymers, LCPs. The current work describes the diverse nature of LCPs, their synthesis, characterization, properties and finally their applications. It describes the manner in which liquid crystallinity or mesomorphism occurs in small molecules, monomer liquid crystals and polymer liquid crystals. Chapter 1 gives a classification of the various ways in which the meso gens may be connected to the polymer chains. Currently, the bulk of LCP material is based on main chain or longitudinal LCPs for use in engineering applications. The side chain or comb polymers are intended for use in electronics and opto-electronic systems and as surfactants. Many other variants and possibilities exist but their properties have not yet been fully studied or used. In this respect it is hoped that the current work will indicate future possibilities as well as discussing current opinion. v Preface vi Chapters 2 and 3 describe methods of characterizing the mesophases.
Download or read book Synthesis and Characterization of Poly methylsiloxane s Containing 5 S 2 Methyl 1 Butyl 2 4 11 Undecan 1 Yloxy Phenyl 1 3 2 Dioxaborinane and 2 4 S 2 Methyl 1 Butoxy Phenyl 5 11 Undecan 1 Yl 1 3 2 Dioxaborinane Constitutional Isomeric Side Groups written by V. Percec and published by . This book was released on 1991 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Previous publications from our laboratory reported the results of our investigations on the molecular engineering of phase transitions of side chain liquid crystalline polymers by using constitutional isomers of rigid rod-like mesogenic groups. Homopolymers based on constitutional isomeric rigid rod-like mesogens exhibit almost identical phase behavior. However, since their structural units are isomorphic within their mesophase and nonisomorphic within their crystalline phase, copolymers based on constitutional isomeric mesogens exhibit an isotropization temperature which is about the weight averaged value of their homopolymers and a highly depressed melting transition temperature. Consequently, copolymerization of these constitutional isomeric mesogens can be used to transform virtual or monotropic mesophases into enantiotropic mesophases. In a previous publication we have reported that isotropization temperatures of homopolymers containing constitutional isomeric mesogens based on a combination of rigid rod-like and flexible moieties are highly different.
Download or read book Liquid Crystalline Polymers Containing Heterocycloalkane Mesogenic Groups 6 Liquid Crystalline Polymethacrylates and Polyacrylates of Trans 2 4 Hydroxyundecanyloxy 3 5 Dimethylphenyl 5 4 Methoxyphenyl 1 3 Dioxane written by Chain S. Hsu and published by . This book was released on 1987 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis and characterization of polymethacrylate and polyacrylate of trans 2-(4-(11-(hydroxyundecanyloxy-3, 5-dimethylphenyl)-5-(4-methoxyphenyl)-1,3-dioxane is presented. Both polymers exhibit nematic mesophases and do not present side-chain crystallization. At temperatures higher than 160 C the 1,3-dioxane-2,5-diyl groups undergo a thermally induced trans-cis isomerization. A radical mechanism was proposed for this isomerization. Keywords: Polyacrylates.
Download or read book Liquid Crystalline Polymers written by Vijay Kumar Thakur and published by Springer. This book was released on 2015-11-16 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces anisotropic innovations in liquid crystalline polymers as well as new nanocomposite materials and testing techniques. The authors detail the newest discoveries of material properties, material types and phases, and material characterization. This interdisciplinary work creates valuable links that strengthen the approach to the evolving field of liquid crystalline polymers/ materials.
Download or read book Liquid Crystalline Polymers written by Division on Engineering and Physical Sciences and published by National Academies Press. This book was released on 1990-02-01 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Liquid Crystalline Polymers Containing Heterocycloalkane Mesogens 4 Biphasic Side Chain Liquid Crystalline Polysiloxanes Containing Trans 5 n Undecanyl 2 4 Methoxyphenyl 1 3 Dioxane and Trans 2 n Decanyl 5 4 Methoxyphenyl 1 3 Dioxane Mesogens written by Chain S. Hsu and published by . This book was released on 1986 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis and characterization of side-chain liquid crystalline polysiloxanes and copolysiloxanes containing trans 5-(n-undecanyl)-2-(4-methoxyphenyl)-1,3-dioxane and respectively trans 2-(n-decanyl)-5-(4-methoxyphenyl)-1-3-dioxane side groups is presented. In most cases the resulting polymers exhibit two glass transition temperatures, i.e., one due to the independent motion of the main chain, and the other due to the independent but cooperative motion of the side chains.
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 Liquid Crystalline Copolymers of Monomer Pairs Containing Mesogenic Units Which Exhibit Constitutional Isomerism written by Virgil Percec and published by . This book was released on 1987 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis and characterization of side-chain liquid crystalline copolymers obtained from a monomer pair containing a mesogenic unit which exhibits constitutional isomerism are presented. The particular example described refers to copolymethacrylates obtained from 4-hydroxy-4'-methoxy-alpha-methylstilbene and 4-methoxy-4'-hydroxy-alpha-methylstilbene containing six methylenic units presents a nematic mesophase, while the polymer containing eleven methylenic units presents a smectic A or C mesophase. None of these polymers exhibited side-chain crystallization.
Download or read book Liquid Crystalline Polymers written by Vijay Kumar Thakur and published by Springer. This book was released on 2015-08-25 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces various applications of liquid crystalline polymers as the emerging new class of high performance novel materials. The authors detail the advantageous properties of these LCs including optical anisotropic, transparency and easy control over structure. This interdisciplinary work includes valuable input from international projects with special focus on the use of liquid crystalline polymers and/or nanocomposites.
Download or read book Synthesis and Characterization of Side chain Liquid Crystalline Polymers Containing Mesogenic Units which Exhibit Constitutional Or Conformational Isomerism written by Chain-Shu Hsu and published by . This book was released on 1987 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
