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Koschella A, Heinze T, Severac E, Moulis C. Regioselective thexyldimethylsilylation of (1➔3)-glucans - Does the linkage type matter. Carbohydr Polym 2024; 343:122439. [PMID: 39174084 DOI: 10.1016/j.carbpol.2024.122439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 06/13/2024] [Accepted: 06/26/2024] [Indexed: 08/24/2024]
Abstract
α- and β-(1➔3)-linked polysaccharides dissolved in N,N-dimethyl acetamide (DMA) were subjected to conversion with thexyldimethylchlorosilane (TDMS-Cl) in presence of pyridine as base. A degree of substitution of TDMS groups (DSSi) between 0.7 and 1.0 was achieved indicating that the β-(1➔3)-linked curdlan (DSSi 0.7) is less reactive than α-(1➔3)-linked glucans (DSSi ca. 1). The synthesis sequence of permethylation, desilylation, and acetylation afforded the corresponding acetyl-methyl derivatives, where unaffected OH groups were methylated and TDMS groups were replaced by acetyl moieties. NMR spectroscopic investigations revealed a highly selective silylation of the primary OH group at position 6 while leaving the secondary OH moieties unaffected. This pronounced selectivity was found to be distinctly higher compared to cellulose and starch. Conversion of (1➔4)-linked polysaccharides dissolved in DMA/LiCl with TDMS-Cl leads to products consisting of both 6-mono-O- and 2,6-di-O- silylated repeating units. Regioselective 6-mono-O-silylation requires the hazardous use of liquid ammonia.
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Affiliation(s)
- Andreas Koschella
- Friedrich Schiller University Jena, Institute for Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Humboldtstraße 10, D-07743 Jena, Germany.
| | - Thomas Heinze
- Friedrich Schiller University Jena, Institute for Organic Chemistry and Macromolecular Chemistry, Center of Excellence for Polysaccharide Research, Humboldtstraße 10, D-07743 Jena, Germany.
| | - Etienne Severac
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 135 avenue de rangueil, 31077 Toulouse, France.
| | - Claire Moulis
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 135 avenue de rangueil, 31077 Toulouse, France.
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Thermoplastic Starch with Poly(butylene adipate- co-terephthalate) Blends Foamed by Supercritical Carbon Dioxide. Polymers (Basel) 2022; 14:polym14101952. [PMID: 35631835 PMCID: PMC9145724 DOI: 10.3390/polym14101952] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/06/2022] [Accepted: 05/07/2022] [Indexed: 01/23/2023] Open
Abstract
Starch-based biodegradable foams with a high starch content are developed using industrial starch as the base material and supercritical CO2 as blowing or foaming agents. The superior cushioning properties of these foams can lead to competitiveness in the market. Despite this, a weak melting strength property of starch is not sufficient to hold the foaming agents within it. Due to the rapid diffusion of foaming gas into the environment, it is difficult for starch to maintain pore structure in starch foams. Therefore, producing starch foam by using supercritical CO2 foaming gas faces severe challenges. To overcome this, we have synthesized thermoplastic starch (TPS) by dispersing starch into water or glycerin. Consecutively, the TPS surface was modified by compatibilizer silane A (SA) to improve the dispersion with poly(butylene adipate-co-terephthalate) (PBAT) to become (TPS with SA)/PBAT composite foam. Furthermore, the foam-forming process was optimized by varying the ratios of TPS and PBAT under different forming temperatures of 85 °C to 105 °C, and two different pressures, 17 Mpa and 23 Mpa were studied in detail. The obtained results indicate that the SA surface modification on TPS can influence the great compatibility with PBAT blended foams (foam density: 0.16 g/cm3); whereas unmodified TPS and PBAT (foam density: 0.349 g/cm3) exhibit high foam density, rigid foam structure, and poor tensile properties. In addition, we have found that the 80% TPS/20% PBAT foam can be achieved with good flexible properties. Because of this flexibility, lightweight and environment-friendly nature, we have the opportunity to resolve the strong demands from the packing market.
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Kaur S, Santra S. Recent Progress in Chemical Modification of the Natural Polysaccharide Guar Gum. Curr Org Synth 2021; 19:197-219. [PMID: 34751122 DOI: 10.2174/1570179418666211109105416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/17/2021] [Accepted: 09/01/2021] [Indexed: 11/22/2022]
Abstract
Guar gum (GG) is a natural heteropolysaccharide. Due to its non-toxic, eco-friendly, and biodegradable nature, GG has found wide applications in many areas, in particular food, paper, textile, petroleum, and pharmaceutical industries. Therefore, GG is often called "Black Gold" as well. Due to the presence of hydroxyl groups, GG can be modified by various methods. The physical and biological properties of GG can be modulated by chemical modifications. In this manuscript, various methods for the chemical modifications of GG have been discussed according to the type of modifications. Mechanistic insights have also been provided whenever possible. In addition, potential applications of new GG derivatives have also been briefly mentioned.
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Affiliation(s)
- Simran Kaur
- Department of Chemistry, School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, Punjab-144411. India
| | - Soumava Santra
- Department of Chemistry, School of Chemical Engineering and Physical Sciences, Lovely Professional University, Phagwara, Punjab-144411. India
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Modification of starch: A review on the application of “green” solvents and controlled functionalization. Carbohydr Polym 2020; 241:116350. [DOI: 10.1016/j.carbpol.2020.116350] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 01/25/2023]
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Wang J, Yang W, Wang J, Wang X, Wu F, Yao J, Zhang J, Lei Z. Regioselective sulfation of Artemisia sphaerocephala polysaccharide: Characterization of chemical structure. Carbohydr Polym 2015; 133:320-7. [DOI: 10.1016/j.carbpol.2015.07.030] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 06/29/2015] [Accepted: 07/08/2015] [Indexed: 10/23/2022]
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Xu WZ, Bar-Nir BBA, Kadla JF. Honeycomb membranes prepared from 3-O-amino acid functionalized cellulose derivatives. Carbohydr Polym 2014; 100:126-34. [DOI: 10.1016/j.carbpol.2012.12.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 11/21/2012] [Accepted: 12/27/2012] [Indexed: 10/27/2022]
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Regioselective synthesis of sulfated guar gum: Comparative studies of structure and antioxidant activities. Int J Biol Macromol 2013; 62:734-40. [DOI: 10.1016/j.ijbiomac.2013.10.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/21/2013] [Accepted: 10/05/2013] [Indexed: 11/23/2022]
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El Seoud OA, Nawaz H, Arêas EPG. Chemistry and applications of polysaccharide solutions in strong electrolytes/dipolar aprotic solvents: an overview. Molecules 2013; 18:1270-313. [PMID: 23337297 PMCID: PMC6270342 DOI: 10.3390/molecules18011270] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 01/02/2013] [Accepted: 01/09/2013] [Indexed: 11/24/2022] Open
Abstract
Biopolymers and their derivatives are being actively investigated as substitutes for petroleum-based polymers. This has generated an intense interest in investigating new solvents, in particular for cellulose, chitin/chitosan, and starch. This overview focuses on recent advances in the dissolution and derivatization of these polysaccharides in solutions of strong electrolytes in dipolar aprotic solvents. A brief description of the molecular structures of these biopolymers is given, with emphases on the properties that are relevant to derivatization, namely crystallinity and accessibility. The mechanism of cellulose dissolution is then discussed, followed by a description of the strategies employed for the synthesis of cellulose derivatives (carboxylic acid esters, and ethers) under homogeneous reaction conditions. The same sequence of presentation has been followed for chitin/chitosan and starch. Future perspectives for this subject are summarized, in particular with regard to compliance with the principles of green chemistry.
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Petzold K, Klemm D, Stein A, Günther W. Synthesis and NMR characterization of regiocontrolled starch alkyl ethers. Des Monomers Polym 2012. [DOI: 10.1163/156855502760408099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
Starch and cellulose are the most abundant and important representatives of renewable biomass. Since the mid-19th century their properties have been changed by chemical modification for commercial and scientific purposes, and there substituted polymers have found a wide range of applications. However, the inherent polydispersity and supramolecular organization of starch and cellulose cause the products resulting from their modification to display high complexity. Chemical composition analysis of these mixtures is therefore a challenging task. Detailed knowledge on substitution patterns is fundamental for understanding structure-property relationships in modified cellulose and starch, and thus also for the improvement of reproducibility and rational design of properties. Substitution patterns resulting from kinetically or thermodynamically controlled reactions show certain preferences for the three available hydroxyl functions in (1→4)-linked glucans. Spurlin, seventy years ago, was the first to describe this in an idealized model, and nowadays this model has been extended and related to the next hierarchical levels, namely, the substituent distribution in and over the polymer chains. This structural complexity, with its implications for data interpretation, and the analytical approaches developed for its investigation are outlined in this article. Strategies and methods for the determination of the average degree of substitution (DS), monomer composition, and substitution patterns at the polymer level are presented and discussed with respect to their limitations and interpretability. Nuclear magnetic resonance spectroscopy, chromatography, capillary electrophoresis, and modern mass spectrometry (MS), including tandem MS, are the main instrumental techniques employed, in combination with appropriate sample preparation by chemical and enzymatic methods.
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Suriano F, Coulembier O, Dubois P. Synthesis of amphiphilic A3B mikto-arm copolymers from a sugar core: Combination of hydrophobic PCL and hydrophilic glycopolymers for biocompatible nanovector preparation. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.24109] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Satyanarayana KG, Arizaga GG, Wypych F. Biodegradable composites based on lignocellulosic fibers—An overview. Prog Polym Sci 2009. [DOI: 10.1016/j.progpolymsci.2008.12.002] [Citation(s) in RCA: 545] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Sugih AK, Picchioni F, Janssen LP, Heeres HJ. Synthesis of poly-(ε)-caprolactone grafted starch co-polymers by ring-opening polymerisation using silylated starch precursors. Carbohydr Polym 2009. [DOI: 10.1016/j.carbpol.2008.12.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Binette A, Gagnon J. Regioselective Silylation of N-Phthaloylchitosan with TBDMS and TBDPS Groups. Biomacromolecules 2007; 8:1812-5. [PMID: 17487971 DOI: 10.1021/bm0610976] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
N-Phthaloylchitosan represents a key intermediate for the regioselective modification of chitosan in organic media. Chemoselective protection of primary alcohols on N-phthaloylchitosan was achieved with tert-butyldimethylsilyl (TBDMS) and tert-butyldiphenylsilyl (TBDPS) groups in imidazole/DMF and DMAP/pyridine. Influence of experimental conditions such as solvent, choice of base, stoichiometry, temperature, and time of reaction was studied regarding the degree of substitution (ds) of silyl groups. TBDMS groups allow higher ds than TBDPS groups. Higher reaction temperatures in different conditions led to lower ds and incomplete substitution. However, regioselective silylation of N-phthaloylchitosan was realized with ds up to 0.92 at room temperature. Silylated derivatives were characterized by elemental analysis, IR, and CP/MAS 13C NMR spectroscopies.
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Affiliation(s)
- Alain Binette
- Département de biologie, chimie et géographie, Université du Québec à Rimouski, 300, allée des Ursulines, Rimouski, Québec, Canada, G5L 3A1
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