Abstract
Symmetrical block oligomers having in common terminal groups (A) consisting of polyoxyethylene (20) stearyl ether are materials of pharmaceutical and cosmetic interest. Phase properties of their aqueous systems and amounts of water typologies were determined by differential scanning calorimetry (DSC).
The overall amount of water absorbed by each investigated oligomer was not significantly influenced by the type of central bridging block, whereas the amount of free water decreased with increasing oligomer concentration in the gel. A number of 60–70 moles of water was found to solvate the oligomer chain. The oligomers studied presented a thermo-reversible gelation with and precipitation under determined temperature conditions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
B. J. Aungst, in: Michael Szycher (Ed.), High Performance Biomaterials — A Comprehensive Guide to Medical and Pharmaceutical Applications, Chap. 34, Technomic Publishing Company, Inc., Lancaster, USA 1991, p. 527.
L. H. Block, in: Alfonso R. Gennaro et al. (Ed.), Remington's Pharmaceutical Sciences, Chap. 88, 17th edition, Philadelphia College of Pharmacy and Science, 1985, p. 1567.
J. Crank and G. S. Park (Eds), Diffusion in Polymers, Academic Press, London 1968.
P. Ashton, J. Hadgraft and K. A. Walters, Pharm. Acta Helv., 61 (1986) 228.
M. Nguyen-Misra and W. L. Mattice, Macromolecules, 28 (1995) 1444.
E. A. Turi (Ed.), Thermal Characterization of Polymeric Materials, Vol. 1, 2nd ed. Academic Press, San Diego 1997.
B. Wunderlich and W. Chen, in A. I. Isayev, T. Kye, and S. Z. D. Cheng, eds., Recent Advances in Liquid Crystalline Polymers. ACS Symp. Series, Washington, DC 1996, p. 232.
J. D. Ferry, Viscoelastic Properties of Polymers, Wiley, New York 1980.
J. G. Nairn, in: Alfonso R. Gennaro et al. (Ed.), Remington's Pharmaceutical Sciences, Chap. 84, 17th edition, Philadelphia College of Pharmacy and Science, 1985, p. 1512.
T. Angell, J. Chem. Phys., 84 (1980) 268.
A. Keller, Faraday Discuss., 101 (1995) 1.
S. Callister, A. Keller and R. M. Hikmet, Makromol. Chem., Macromol. Symp., 39 (1990) 19.
S. Hvidt, E. B. Jørgensen, W. Brown and K. Schillén, J. Phys. Chem., 98 (1994) 12320.
J. M. Guenet, Macromol. Symp., 114 (1997) 97.
Y. Deng, G-E Yu, C. Price and C. Booth, J. Chem. Soc. Faraday Trans., 88 (1992) 1441.
Y. Deng, C. Price and C. Booth, Eur. Polym. J., 30 (1994) 103.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Fernandes, E.G., Krauser, S., Samour, C.M. et al. Symmetric Block Oligomers. Gelation characteristics by DSC. Journal of Thermal Analysis and Calorimetry 61, 551–564 (2000). https://doi.org/10.1023/A:1010133904733
Issue Date:
DOI: https://doi.org/10.1023/A:1010133904733