Comparison study of TEMPO-analogous compounds on oxidation efficiency of wood cellulose for preparation of cellulose nanofibrils
| Autor: | Takuya Isogai, Tsuguyuki Saito, Shinichiro Iwamoto, Akira Isogai, Weihua Kai, Tadahisa Iwata |
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| Rok vydání: | 2010 |
| Předmět: |
Reaction mechanism
Morphology (linguistics) Polymers and Plastics Chemical modification Nitroxyl Condensed Matter Physics behavioral disciplines and activities humanities Catalysis chemistry.chemical_compound chemistry Mechanics of Materials Nanofiber Polymer chemistry Materials Chemistry Carboxylate Cellulose |
| Zdroj: | Polymer Degradation and Stability. 95:1394-1398 |
| ISSN: | 0141-3910 |
| DOI: | 10.1016/j.polymdegradstab.2010.01.017 |
| Popis: | The effect of chemical structures of TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxy radical) derivatives and its analogous compounds on oxidation efficiency of C6 primary hydroxyls of wood cellulose was investigated using the NaClO/NaBr system at pH 10. Because the oxidation takes place selectively on the surfaces of cellulose microfibrils, individualized and surface-oxidized cellulose nanofibrils can be obtained by simple mechanical treatment in water, when sufficient amounts of carboxylate groups are formed homogeneously in cellulose microfibrils. 4-acetamide-TEMPO and 4-methoxy-TEMPO showed efficient catalytic behavior with short reaction times ( 1.1 mmol/g) in oxidation of wood cellulose, comparable to TEMPO. Correspondingly, these TEMPO derivatives as well as TEMPO gave high nanofibril yields >56%. On the other hand, the use of 4-hydroxy-TEMPO and 4-oxo-TEMPO resulted in the lowest efficiency in oxidation: oxidation times >24 h, carboxylate contents |
| Databáze: | OpenAIRE |
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