Abstract
6-O-Alkyl-celluloses with well-defined ratio of ethyl and methyl groups at position 6 were prepared by ring-opening copolymerization of 6-O-ethyl and 6-O-methyl glucose 1,2,4-orthopivalate derivatives. An aqueous solution of 6-O-ethyl-cellulose having no methyl group was found to be thermo-responsive to be turbid at ~70 °C. An aqueous solution of 6-O-ethyl-cellulose with higher molecular weight showed endothermic and exothermic peaks in the heating and cooling curves of DSC measurements, respectively. However, 6-O-alkyl-cellulose having 10% methyl group lost its thermo-responsive character. 6-O-Alkyl-celluloses having more than ten percent of ethyl group at position 6 became water-soluble, though 6-O-methyl-cellulose is insoluble in water. Thus, 6-O-ethyl group was found to be of importance for the water solubility of regioselective 6-O-alkyl-celluloses. Furthermore, a small amount of methyl group introduced at C6 position was found to affect some of physical properties of 6-O-alkyl-celluloses such as thermo responsive property.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ifuku S, Nakai S, Kamitakahara H, Takano T, Tsujii Y, Nakatsubo F (2005) Preparation and characterization of monolayer and multilayer langmuir-blodgett films of a series of 6-O-alkylcelluloses. Biomacromolecules 6(4):2067–2073
Kamitakahara H, Hori M, Nakatsubo F (1996) Substituent effect on ring-opening polymerization of regioselectively acylated α-d-glucopyranose 1, 2, 4-orthopivalate derivatives. Macromolecules 29(19):6126–6131
Kamitakahara H, Nakatsubo F, Klemm D (2006) Block co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides as model compounds for methylcellulose and its dissolution/gelation behavior. Cellulose 13(4):375–392
Kamitakahara H, Nakatsubo F, Klemm D (2007) New class of carbohydrate-based nonionic surfactants: diblock co-oligomers of tri-O-methylated and unmodified cello-oligosaccharides. Cellulose 14(5):513–528
Kamitakahara H, Koschella A, Mikawa Y, Nakatsubo F, Heinze T, Klemm D (2008) Syntheses and comparison of 2, 6-di-O-methyl celluloses from natural and synthetic celluloses. Macromol Biosci 8(7):690–700
Kamitakahara H, Funakoshi T, Takano T, Nakatsubo F (2009) Syntheses of 2,6-O-alkyl celluloses: influence of methyl and ethyl groups regioselectively introduced at O-2 and O-6 positions on their solubility. Cellulose. doi:https://doi.org/10.1007/s10570-009-9332-y
Karakawa M (2003) Chemical synthesis of high-regioselectively methylated celluloses by a cationic ring-opening polymerization (Kyoto). Ph.D. Thesis, Kyoto University
Nakatsubo F, Kamitakahara H, Hori M (1996) Cationic ring-opening polymerization of 3, 6-di-O-benzyl-α-d-glucose 1, 2, 4-orthopivalate and the first chemical synthesis of cellulose. J Am Chem Soc 118(7):1677–1681
Acknowledgments
This investigation was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (No. 18680009).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kamitakahara, H., Funakoshi, T., Nakai, S. et al. Syntheses of 6-O-ethyl/methyl-celluloses via ring-opening copolymerization of 3-O-benzyl-6-O-ethyl/methyl-α-d-glucopyranose 1,2,4-orthopivalates and their structure–property relationships. Cellulose 16, 1179–1185 (2009). https://doi.org/10.1007/s10570-009-9339-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10570-009-9339-4