Dielectric properties of the collagen-glycosaminoglycans scaffolds in the temperature range of thermal decomposition.
Dielectric spectroscopy has been applied to study the decomposition process of unmodified collagen and chondroitin sulfate (CS)- and hyaluronic acid (HA)-modified collagen. Measurements were performed over the frequency range from 10 Hz to 100 kHz and at temperatures from 22 to 260 degrees C. According to the Kramers-Kronig relationship a dispersion is apparent in both epsilon' and epsilon'' for the three materials below 140 degrees C and at higher temperatures as a broad peak around 220-230 degrees C, respectively. The values of epsilon' and epsilon'' at the same temperature for constant frequency are higher in HA-modified collagen than in the unmodified collagen. However, small differences are shown in these parameters between CS-modified collagen and unmodified collagen. The observed dispersion around 220-230 degrees C corresponds to the decomposition of unmodified and CS- and HA-modified collagen. Power-low responses are observed for the frequency dependence of ac conductivity for unmodified and modified collagen. The behaviour observed for temperature dependencies of the exponent n for the three materials is considered to be related to the proton polarization and conduction processes.
Pietrucha
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K
Institute of Polimer and Dye Technology, Technical University of Łódź, Stefanowskiego 12/16, 90-924 Łódź, Poland.
Marzec
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E
D003094:Collagen / Q000737:chemistry*; D004553:Electric Conductivity; D006025:Glycosaminoglycans / Q000737:chemistry*; D011522:Protons; D013057:Spectrum Analysis / Q000379:methods; D013816:Thermodynamics; D013997:Time Factors
D006025:Glycosaminoglycans; D011522:Protons; D003094:Collagen