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Andrea M. Kasko - One of the best experts on this subject based on the ideXlab platform.
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Biodegradable Aromatic–Aliphatic Poly(ester–amides) from Monolignol-Based Ester Dimers
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Brianna M. Upton, Andrea M. KaskoAbstract:Biobased polymers with tunable properties have received increased attention in the literature due to a decline in petroleum reserves. Owing to its low cost, abundance, and Aromatic Structure, lignin has great potential as a feedstock for value-added polymeric products. In this work, we condensed carboxylic acid precursors with monolignols to generate reactive dimers for polymer synthesis. Three different Aromatic ester dimers, each corresponding to a different monolignol, were synthesized and characterized. The dicarboxylic acid dimers were converted to the corresponding diacid chloride in situ with thionyl chloride, and a series of poly(ester–amides) were synthesized via interfacial polymerization of these diacid chlorides with seven different aliphatic or Aromatic diamines. The thermal properties (decomposition, glass transition temperature, and melting temperature) and hydrolytic stability in acidic and neutral aqueous conditions of the resulting polymers were studied.
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biodegradable Aromatic aliphatic poly ester amides from monolignol based ester dimers
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Brianna M. Upton, Andrea M. KaskoAbstract:Biobased polymers with tunable properties have received increased attention in the literature due to a decline in petroleum reserves. Owing to its low cost, abundance, and Aromatic Structure, lignin has great potential as a feedstock for value-added polymeric products. In this work, we condensed carboxylic acid precursors with monolignols to generate reactive dimers for polymer synthesis. Three different Aromatic ester dimers, each corresponding to a different monolignol, were synthesized and characterized. The dicarboxylic acid dimers were converted to the corresponding diacid chloride in situ with thionyl chloride, and a series of poly(ester–amides) were synthesized via interfacial polymerization of these diacid chlorides with seven different aliphatic or Aromatic diamines. The thermal properties (decomposition, glass transition temperature, and melting temperature) and hydrolytic stability in acidic and neutral aqueous conditions of the resulting polymers were studied.
Brianna M. Upton - One of the best experts on this subject based on the ideXlab platform.
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Biodegradable Aromatic–Aliphatic Poly(ester–amides) from Monolignol-Based Ester Dimers
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Brianna M. Upton, Andrea M. KaskoAbstract:Biobased polymers with tunable properties have received increased attention in the literature due to a decline in petroleum reserves. Owing to its low cost, abundance, and Aromatic Structure, lignin has great potential as a feedstock for value-added polymeric products. In this work, we condensed carboxylic acid precursors with monolignols to generate reactive dimers for polymer synthesis. Three different Aromatic ester dimers, each corresponding to a different monolignol, were synthesized and characterized. The dicarboxylic acid dimers were converted to the corresponding diacid chloride in situ with thionyl chloride, and a series of poly(ester–amides) were synthesized via interfacial polymerization of these diacid chlorides with seven different aliphatic or Aromatic diamines. The thermal properties (decomposition, glass transition temperature, and melting temperature) and hydrolytic stability in acidic and neutral aqueous conditions of the resulting polymers were studied.
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biodegradable Aromatic aliphatic poly ester amides from monolignol based ester dimers
ACS Sustainable Chemistry & Engineering, 2018Co-Authors: Brianna M. Upton, Andrea M. KaskoAbstract:Biobased polymers with tunable properties have received increased attention in the literature due to a decline in petroleum reserves. Owing to its low cost, abundance, and Aromatic Structure, lignin has great potential as a feedstock for value-added polymeric products. In this work, we condensed carboxylic acid precursors with monolignols to generate reactive dimers for polymer synthesis. Three different Aromatic ester dimers, each corresponding to a different monolignol, were synthesized and characterized. The dicarboxylic acid dimers were converted to the corresponding diacid chloride in situ with thionyl chloride, and a series of poly(ester–amides) were synthesized via interfacial polymerization of these diacid chlorides with seven different aliphatic or Aromatic diamines. The thermal properties (decomposition, glass transition temperature, and melting temperature) and hydrolytic stability in acidic and neutral aqueous conditions of the resulting polymers were studied.
Concepció Rovira - One of the best experts on this subject based on the ideXlab platform.
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the interplay of inverted redox potentials and Aromaticity in the oxidized states of new π electron donors 9 1 3 dithiol 2 ylidene fluorene and 9 1 3 dithiol 2 ylidene thioxanthene derivatives
Chemistry: A European Journal, 2006Co-Authors: Samia Amriou, Dmitrii F. Perepichka, Enrique Ortí, Rafael Viruela, Changsheng Wang, Andrei S. Batsanov, Martin R Bryce, Jose Vidalgancedo, Concepció RoviraAbstract:Derivatives of 9-(1,3-dithiol- 2-ylidene)fluorene (9) and 9-(1,3-di- thiol-2-ylidene)thioxanthene (10) have been synthesised using Horner-Wads- worth-Emmons reactions of (1,3-di- thiol-2-yl)phosphonate reagents with fluorenone and thioxanthen-9-one. X- ray crystallography, solution electro- chemistry, optical spectroscopy, spec- troelectrochemistry and simultaneous electrochemistry and electron para- magnetic resonance (SEEPR), com- bined with theoretical calculations per- formed at the B3P86/6-31G** level, elucidate the interplay of the electronic and structural properties in these mole- cules. These compounds are strong two-electron donors, and the oxidation potentials depend on the electronic Structure of the oxidised state. Two, single-electron oxidations (E ox E ox ) resulting in a single, two- electron oxidation process. The latter is due to the Aromatic Structure of the thioxanthenium cation (formed on the loss of a second electron), which stabil- ises the dication state (10 2 + ) compared with the radical cation. This contrasts with the nonAromatic Structure of the fluorenium cation of system 9 .T he two-electron oxidation wave in the thioxanthene derivatives is split into two separate one-electron waves in the corresponding sulfoxide and sulfone derivatives 27-29 owing to destabilisa- tion of the dication state.
Dmitrii F. Perepichka - One of the best experts on this subject based on the ideXlab platform.
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the interplay of inverted redox potentials and Aromaticity in the oxidized states of new π electron donors 9 1 3 dithiol 2 ylidene fluorene and 9 1 3 dithiol 2 ylidene thioxanthene derivatives
Chemistry: A European Journal, 2006Co-Authors: Samia Amriou, Dmitrii F. Perepichka, Enrique Ortí, Rafael Viruela, Changsheng Wang, Andrei S. Batsanov, Martin R Bryce, Jose Vidalgancedo, Concepció RoviraAbstract:Derivatives of 9-(1,3-dithiol- 2-ylidene)fluorene (9) and 9-(1,3-di- thiol-2-ylidene)thioxanthene (10) have been synthesised using Horner-Wads- worth-Emmons reactions of (1,3-di- thiol-2-yl)phosphonate reagents with fluorenone and thioxanthen-9-one. X- ray crystallography, solution electro- chemistry, optical spectroscopy, spec- troelectrochemistry and simultaneous electrochemistry and electron para- magnetic resonance (SEEPR), com- bined with theoretical calculations per- formed at the B3P86/6-31G** level, elucidate the interplay of the electronic and structural properties in these mole- cules. These compounds are strong two-electron donors, and the oxidation potentials depend on the electronic Structure of the oxidised state. Two, single-electron oxidations (E ox E ox ) resulting in a single, two- electron oxidation process. The latter is due to the Aromatic Structure of the thioxanthenium cation (formed on the loss of a second electron), which stabil- ises the dication state (10 2 + ) compared with the radical cation. This contrasts with the nonAromatic Structure of the fluorenium cation of system 9 .T he two-electron oxidation wave in the thioxanthene derivatives is split into two separate one-electron waves in the corresponding sulfoxide and sulfone derivatives 27-29 owing to destabilisa- tion of the dication state.
Kei Ohkubo - One of the best experts on this subject based on the ideXlab platform.
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porphyrins fused with strongly electron donating 1 3 dithiol 2 ylidene moieties redox control by metal cation complexation and anion binding
Journal of the American Chemical Society, 2013Co-Authors: Nathan L Bill, Masatoshi Ishida, Steffen Bahring, Jong Min Lim, Sangsu Lee, Christina M Davis, Vincent M Lynch, Kent A Nielsen, Jan O Jeppesen, Kei OhkuboAbstract:A new class of redox-active free base and metalloporphyrins fused with the 1,3-dithiol-2-ylidene subunits present in tetrathiafulvalene, termed MTTFP (M = H2, Cu, Ni, Zn), have been prepared and characterized. The strong electron-donating properties of MTTFP were probed by electrochemical measurement and demonstrated that oxidation potentials can be tuned by metalation of the free base form, H2TTFP. X-ray crystal Structures of H2TTFP, ZnTTFP, and CuTTFP revealed that a severe saddle-shape distortion was observed with the dithiole rings bent out of the plane toward one another in the neutral form. In contrast, the Structure of the two-electron oxidized species (CuTFFP2+) is planar, corresponding to a change from a nonAromatic to Aromatic Structure upon oxidation. A relatively large two-photon absorption (TPA) cross-section value of H2TTFP2+ (1200 GM) was obtained for the free base compound, a value that is much higher than those typically seen for porphyrins (<100 GM). Augmented TPA values for the metal co...