Download or read book Synthesis and Characterization of Substituted Polyphenylene Oligomers written by Susan T. Pasco and published by . This book was released on 1997 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Chara c terization of Substituted Polyphenylene Oligomers written by Susan T. Pasco and published by . This book was released on 1997 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Poly arylene Ethers and Functionalized Oligomers written by Michael J. Jurek and published by . This book was released on 1987 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Perfluorovinylether terminated Imide Oligomers written by T. Edwin Freeman and published by . This book was released on 1997 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Conjugated Polymers and Oligomers written by Huinan Yu and published by . This book was released on 1997 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Organic and Organometallic Conducting Polymers and Oligomers written by Michael Oliver Wolf and published by . This book was released on 1994 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Discrete Polyene Oligomer Synthesis and Related Polymer Characterization written by Jillian Elizabeth Hafer and published by . This book was released on 2006 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molybdenum complexes ... were used to synthesize polyene oligomeric compounds with up to 15 conjugated double bonds by reaction with aldehyde compounds in a Wittig-like fashion. The optical properties of highly nr-conjugated systems are investigated due to potential application in photooptical materials. To this end, discrete oligomers have been synthesized in order to study properties of the varying lengths and to what extent solvent and substitution patterns affect these properties. Trends have been established based on solvent polarity and steric bulk at the ester functionality. Extrapolation of the data here yields pertinent information to the polymer field since the oligomers mimic polymeric materials made by RCMP of 1,6-heptadiyne substrates that are fully five-membered ring containing structures with a disubstitution pattern of ester functionalities.
Download or read book Synthesis and Characterization of Poly dialkyldithiophenes and Poly diacetylene Oligomers written by Rosa Maria Souto Maior and published by . This book was released on 1988 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Polythiophene Derivatives written by Xin Chen and published by ProQuest. This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In Chapter 1, the history of conducting polymers, especially polythiophene and its derivatives, was briefly reviewed. Different approaches of structural modifications to afford small bandgap polythiophene derivatives were discussed. The emergence of metal-containing polymers (metallopolymers) as functional materials has attracted tremendous attention around the world. Introduction of metals into thiophene-based oligomers and polymers, whether the backbone or the side chain of the pi-conjugated framework, the electronic, optical, or magnetic properties of the material are expected to be significantly affected by metals through various mechanisms. Synthesis methods to prepare poly(thienylene vinylene) were also briefly reviewed in this chapter. In Chapter 2, the motivations and objectives were briefly discussed. Two structurally similar compounds, thieno[3,4-d]-1,3-dithiole-2-thione and thieno[3,4-d]-1,3-dithiol-2-one are the starting point of this project due to their unique carbondithiolate structures, which may lead to metal-dithiolate coordinated oligomers or/and polymers, or polymers crosslinked by DTTTF units. For the preparation of monomers, six types of reactions were systematically studied with focus on thieno[3,4-d]-1,3-dithiol-2-one to prepare different direvatives. Different halogenated compounds, Mannich bases, chloromethylated compounds, a number of nucleophilic substituted derivatives and a DTTTF analogue from chloromethylated compounds were successful synthesized. All products were fully characterized through 1H and 13C-NMR, FT-IR, ESI-TOF high resolution mass spectroscopy. The halogenated products were prepared through halogensuccinimides or other halogenation reagents such as Br2, I2. These halogenated compounds may be candidates to prepare homopolymer and/or copolymers bearing carbondithiolate structures by cross-coupling reactions. 4,6-Bis(chloromethyl) thieno[3,4- d]-1,3-dithiol-2-one and its nucleophilic derivatives may be good monomers for the two-step precursor polymerization to achieve fully conjugated poly(thienylene vinylene) derivatives and even metallopolymers with metal-dithiolate coordinations. Attempted polymerization reactions to homopolymers and copolymers through directly C-C coupling, such as transitional metal catalyzed cross-coupling, Stille reaction, and Ullman reaction, et al. were discussed in the beginning of Chapter 3. Base-promoted and acid-promoted polymerizations were attempted to afford soluble precursor polymers with carbondithiolate structures. However, all the symmetrical thiophene derivatives did not successfully yield processable precursor polymers; asymmetrical monomers generated some possibilities for future study. Synthesis of thiophene-based oligomers, such as dimmers (dithienyl compounds), trimers (trithienyl compounds), and heptamers were also explored in chapter 3, followed by preparation of thiophene-based copolymers through Wittig-Horner reactions. Properties of oligomers, especially trimers were well characterized by NMR, FT-IR, and ESI-TOF. Several conjugated DTTTF derivatives from trimers were prepared by the triethyl phosphite cross-coupling method. These conjugated DTTTF compounds posses some unique properties. They are stable in solid forms, but may be doped in solution forms. The copolymers were characterized by elemental analysis, and FT-IR. UV-Vis spectra of copolymers show their bandgap values are aroud 1.87eV (UV edge calculation). In the Experimental chapter, all reaction conditions of preparation of new annulated thiophene derivatives and oligomers were documented in details. Physical and spectroscopic properties of these new compounds were also presented in this chapter. Key words. polythiophene, oligomer, conjugation, synthesis, characterization, DTTTF, metallopolymer.
Download or read book Synthesis and Characterization of End capped Polyimide Oligomers written by Anjula Pamidimukkala and published by . This book was released on 1983 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ethynyl End capped Polyimide Oligomers Containing Oxyethylene Linkages written by K. Sridhar and published by . This book was released on 1987 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Ortho phenylene Oligomers written by Jason L. Crase and published by . This book was released on 2010 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ortho-Phenylene oligomers are a class of organic molecules that are both chemically and synthetically interesting. Similar molecules have found uses in organic light emitting diodes and organic semiconductors as well as other applications. They are also potential precursors to graphene-like nanoribbons. Little work has been done with ortho-phenylene oligomers, as para -phenylene oligomers have received most of the attention. We have developed a synthesis based on alternating Suzuki-Miyaura couplings and activation of hydroxyls. The ortho-phenylene oligomers are also structurally interesting as there are indications that they assume helical conformations in solution.
Download or read book Synthesis and Characterization of Polyimides with Twisted Configurations written by Lei Wang and published by . This book was released on 2005 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The overall goal of this work was to develop new polyimide systems for aerospace and optical applications. The work was divided into two parts. The first included the synthesis and characterization of low melt viscosity imide oligomers, and the second included the synthesis and characterization of polyimides with twisted configurations. The objective of the first part was to develop phenylethynyl-terminated imide oligomers for use in resin transfer molding (RTM) or resin infusion (RIF) composite fabrication. Some A-B monomer precursors, which possessed both nitro and anhydride functionalities, were synthesized for use in preparation of well-defined oligometers. Thus, a series of star-shaped oligomers and a series of linear oligomers containing twisted-biphenyl structures were prepared from different diamines and dianhydrides and then end-capped with 4-phenylethynylphthalic anhydride (PEPA). Most of the star-shaped oligomers displayed either high melt viscosities or high Tgs and Tms. However, one oligomer which was prepared from 1,3,5-tris(3-aminophenoxy)benzene displayed a low melt viscosity of 1 poise at 260°C and could be thermally cured to resin with a Tg above 350°C. Some of the linear twisted oligomers, which were prepared from 2,2'-bis(o-aminophenoxy)biphenyl, also displayed very low melt viscosities that ranged from 0.5 to 15 poise at 280°C. These materials could be thermally cured to resins with Tgs near 300°C. Oligomer blends were also prepared by solution mixing. Some of blends also displayed very low melt viscosities that ranged from 2 to 10 poise at 280°C. The blends could be thermally cured to resins with Tgs above 300°C. The objective of the second part of this work was to develop polyimides for use in optical applications that require non-biregringent materials. Thus, four series of polymers were prepared from 2,2'-bis(m-aminophenoxy)biphenyl, 2,2'-bis(o-aminophenoxy)biphenyl, 2,2'-bis(2-amino-4-trifluoromethylphenoxy)biphenyl and 2,2'-bis(2,3-dicarboxyphenoxy)biphenyl dianhydride. The polymers containing twisted biphenyl structures were soluble in common organic solvents and could be solution cast into clear, transparent flexible films 10-15 [mu]m thick. The films displayed birefringences ranging from 0.0257 to 0.0021"--Abstract.
Download or read book Synthesis and Characterization of Substituted Cyclopentadienyltitanium Complexes for Use in Olefin Polymerizations written by Scot M. Barry and published by . This book was released on 1993 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nylon 6 6 Oligomers written by Paul D. Johnson and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Unsymmetrical Perylene Derivatives and Perylene Oligomers written by Runkun Sun and published by . This book was released on 2013 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Chapter 1, the history of perylene, PDI derivatives and PDI oligomers are introduced. Their corresponding properties and applications also are introduced. Furthermore, the synthetic methods for different kinds of PDI derivatives, both advantages and disadvantages, are discussed thoroughly.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
