Download or read book Synthesis of Regioregular Thiophene Oligomers and Polymers with Amino and Carboxylic Acid Substituents Protection of 3 aminomethyl thiophene by a Novel Reversible Thienopyrrole Synthesis and Ionochromism in 2 5 poly thiophene 3 propionic Acid written by Paul C. Ewbank and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1995 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Thiophene Oligomers Containing 3 4 Dibutylthiophenes and Synthesis of Related Mixed Oligomers written by Michael Eric Benz and published by . This book was released on 1992 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Thiophene containing Oligomers and Polymers written by James Paul Parakka and published by . This book was released on 1995 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Soluble Alpha Thiophene Oligomers Monomer to Octamer written by and published by . This book was released on 1992 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Described is the detailed synthesis of alpha-thiophene oligomers ranging from the monomer to the octamer that are silylated at the alpha and omega positions. The terminal trimethylsilyl groups allow the monomer, dimer, and trimer to be freely soluble in numerous organic solvents. The higher homologs, trimer through octamer have, in addition to the terminal trimethylsilyl groups, methyl groups symmetrically substituting one or more of the thiophene units in order to enhance the solubility of the systems. Methyl substitution can not be on the 3-position of terminal thiophene units or else rapid protodesilylation occurs in thiophene oligomeric intermediates greater than two units long. The UV-visible spectroscopic characteristics of the synthesized oligomers suggest that, in solution, electrochemically prepared poly(3alkyl-a-thiopbene) effectively has only 6-7 contiguous conjugated alpha- thiophene units. However, in the solid state, the effective conjugation path in the polymer is much longer. The effect of d pi-pi-conjugation between the terminal silicon atom and the conjugated system was also investigated by executing the quantitative protodesilylation of the pentameric oligothiophene.
Download or read book Synthesis and Characterization of Novel Regioregular Polythiophenes Random Copolymers of Thiophene and Studies of the GRIM Polymerization Method for the Synthesis of Polythiophenes written by Richard L. Pilston and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Synthesis of Precursors to Conjugated Polymers written by 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 Thiophene Based Poly Arylene Ether Ketone s Polymerization of Bis 5 Chlorothienyl 2 Ketone with 4 4 Isopropylidenediphenol written by and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our research is focused on the general synthesis of a new class of wholly aromatic thermoplastic engineering polymers based on novel thiophene monomers. Structural aerospace and automotive composites that utilize thermoplastic matrix resins have the potential to offer significant performance and processing advantages over thermosetting matrix resins; therefore, research is targetted for the development of such advanced thermoplastic resins using new chemistry methodologies. Introduction of 2,5-thiophene units would allow for the synthesis of novel thermoplastic poly(arylene ether ketone)s possessing a wider processing window related to the unique molecular geometry of the 2,5 thiophene moiety; its nonlinearity has a 148 deg angle which is between the 180 deg and 120 deg angles associated with the commercially utilized p- and m- phenylene units. Our primary focus was to synthesize direct analogues of ICI's Poly(ether ether ketone), PEEK, elucidating whether nucleophilic aromatic substitution reactions on activated halothiophenes proceed with sufficient conversions to allow for the synthesis of novel thermoplastic poly(arylene ether ketone)s. The short-term objective was to synthesize model compounds by direct nucleophilic substitution of chlorine on thiophene by addition of the activated 2-benzoyl-5- chlorothiophene to t-butylphenol treated with potassium carbonate.
Download or read book Decarboxylative Cross Coupling as An Efficient Synthetic Tool for Thiophene Based Materials written by Jiang Tian Liu and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conjugated thiophene-based material are highly desired materials in various fields of organic electronic materials. Poly/oligothiophene are among the most common substrate used in many different organic electronic materials. The general synthesis involves cross-coupling reactions such as Migita-Stille, Corriu-Kumada, Negishi, and Suzuki-Miyaura. These reactions are robust methodologies, but often involves organometallic reagents and produce metallic waste. Direct (hetero)arylation has been proposed as a greener approach for constructing conjugate-polymeric materials. However, for the many thiophene-based materials they suffer from regioselectivity issues and unwanted side-reactions. Alternatively, decarboxylative cross- coupling provides excellent regioselectivity through the carboxylic acid functional group, that has been demonstrated as an excellent synthetic tool for bi-aryl and/or tri-aryl targets. We envisioned utilizing this method as an efficient strategy for constructing a library of oligothiophenes, where it would be complementary to existing methodologies, and provides a greener approach for green energy applications. Herein, we developed improved reaction conditions without the need of base to prepare a library of poly/oligothiophene. The modularity of our new approach is demonstrated with a scope of 25 different type of symmetric oligothiophenes with highlights in synthesizing symmetrical oligothiophenes with up to 10 thiophene units. Furthermore, this method was also applied towards the synthesis of regioregular oligothiophene and polythiophene. Decarboxylative cross-coupling has demonstrated complete chemoselectivity for thiophene-based oligomers through this work and proven as a comprehensive greener approach compared to the existing synthetic methodologies.
Download or read book The Preparation of Thiophene and Condensed Thiophene Compounds by the Oxidative Cyclodehydrogenation of alpha thiopyruvic Acids written by Richard Emory Cline and published by . This book was released on 1951 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of 2 2 5 2 terpyrrole 2 5 Bis 2 pyrryl thiophene and Substituted Analogs written by Bryon Anderson Merrill and published by . This book was released on 1990 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Sysnthesis and Properties of Regioregular Poly 2 substituted Thiophenes with Polyetheric Substituents Some Properties of Regioregular Poly 3 alkylthiophenes and Efforts Toward the Synthesis of Well defined Poly pyrrole Derivatives written by Shawn P. Williams and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Polymerization Methodology Synthesis of Thiophene Based Heterocyclic Polyethers written by J. M. DeSimone and published by . This book was released on 1992 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new methodology is described for the synthesis of aromatic heterocyclic polyethers which employs thienyl-phenyl ether bond formation as the polymer forming reaction. The efficacy of the new polymerization methodology was first investigated with model compounds where the potassium salt of t-butylphenoxide was found to quantitatively displace the activated chloride on 2benzoyl-5-chlorothiophene to yield 2-benzoyl-5-(4-t-butylphenoxy)thiophene. The model reaction was extended to the synthesis of high polymer using bis(5-chlorothienyl-2)ketone and 4,4'isopropylidenediphenol in an azeotroping mixed solvent system with K2CO3. The resulting polymer was characterized to confirm its composition, structure, and molar mass. This new methodology uses facile synthetic routes and economically feasible starting materials and opens the way to a large variety of heterocyclic, aromatic polyethers which are generally applicable for utilization as advanced materials for structural composites. Thiophene, Heterocyclic polyethers, PEEK, Thermoplastic composites.
Download or read book Synthesis and Characterization of 3 Oligo dimethylsiloxane Thiophene Macromonomers written by Marlene Waugaman and published by . This book was released on 1998 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Properties of Water Soluble Conducting Poly 3 alkylsulfonate thiophenes microform written by Maria Isabel Arroyo Villan and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1993 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis by Melt polymerization of a Novel Series of Bio based and Biodegradable Thiophene containing Copolyesters with Promising Gas Barrier and High Thermomechanical Properties written by Lesly Dasilva Wandji Djouonkep and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Volatile global oil prices, owing to the scarcity of fossil resources, have impacted the cost of producing petrochemicals. Therefore, there is a need to seek novel, renewable chemicals from biomass feedstocks that have comparable properties to petrochemicals. In this study, synthesis, thermal and mechanical properties, and degradability studies of a novel series of sustainable thiophene-based copolyesters like poly(hexylene 2,5-thiophenedicarboxylate-co-bis(2-hydroxyethoxybenzene) (PTBxHy) were conducted via a controlled melt polymerization method. Fourier-transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopy techniques elucidated the degree of randomness and structural properties of copolyesters. Meanwhile, gel permeation chromatography (GPC) analysis showed a high average molecular weight in the range of 67.4-78.7 × 103 g/mol. The glass transition temperature (Tg) was between 69.4 and 105.5 °C, and the melting point between 173.7 and 194.2 °C. The synthesized polymers outperformed poly(ethylene 2,5-thiophenedicarboxylate) (PETF) and behaved similarly to polyethylene terephthalate. The copolyesters exhibited a high tensile strength of 46.4-70.5 MPa and a toughness of more than 600%, superior to their corresponding homopolyesters. The copolyesters, which ranged from 1,4-bis(2-hydroxyethyl)benzene thiophenedicarboxylate (TBB)-enriched to hexylene thiophenedicarboxylate (THH)-enriched, offered significant control over crystallinity, thermal and mechanical properties. Enzymatic hydrolysis of synthetized polymers using porcine pancreatic lipase (PP-L) over a short period resulted in significant weight losses of 9.6, 11.4, 30.2, and 35 wt%, as observed by scanning electron microscopy (SEM), with perforations visible on all surfaces of the films. Thus, thiophene-based polyesters with cyclic aromatic structures similar to terephthalic acid (TPA) show great promise as PET mimics. At the same time, PP-L appears to be a promising biocatalyst for the degradation of bioplastic waste and its recycling via re-synthesis processes
Download or read book Exploring Chemically Modified Polymers written by Yaroslav Oleksenko and published by . This book was released on 2008 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Novel synthetic method for the preparation of aryl substituted 2-amino-1.3,4-oxadiazole functionalized polyacrylic acid has been developed. The synthetic procedure does not require harsh conditions or elevated temperatures and avoids use of the toxic mercury salts as dehydrothiolating agent. The key reaction leading to the formation of desired 1,3,4-oxadiazole conjugated polymers involves in situ formation of the thiosemicarbazide from hydrazide precursor, followed by dehydrothiolation initiated by Mukaivama;s reagent and formation of the desired oxadiazole ring system at room temperature. The aryl substituted 2-amino-1,3,4-oxadiazole functionalized polyacrylic acids 76 were obtained in excellent yields with oxadiazole substitution levels of 46-51%, suggesting that now the polymers mainly contain two functional groups: carboxylic acid and aryl substituted 2-amino-1,3,4-oxadiazole.
