Surface structure and properties of poly-(ethylene terephthalate) hydrolyzed by alkali and cutinase |
| |
Authors: | Ilaria Donelli Vincent A. Nierstrasz |
| |
Affiliation: | a Stazione Sperimentale per la Seta, via Giuseppe Colombo 83, 20133 Milano, Italy b Department of Textiles, Ghent University, Technologiepark 907, 9052 Gent, Belgium c Dipartimento di Biochimica “G. Moruzzi”, Sezione di Chimica e Propedeutica Biochimica, Università di Bologna, via Belmeloro 8/2, 40126 Bologna, Italy |
| |
Abstract: | This study was aimed at comparatively investigating the hydrolysis of crystalline and amorphous poly-(ethylene terephthalate) films by alkali and cutinase. Changes of surface properties were investigated by FTIR spectroscopy (ATR mode). The A1341/A1410 and I1120/I1100 absorbance ratios, and the full width at half maximum of the carbonyl stretching band (FWHM1715) were used to evaluate the polymer crystallinity and its changes upon hydrolysis. The effect of different treatments on chain orientation was evaluated by calculating R ratios of appropriate bands. The spectroscopic indexes showed that both alkali and enzyme treatments induced structural and conformational rearrangements with a consequent increase in crystallinity in both amorphous and crystalline films. The crystalline PET film was modified more strongly by alkali than by cutinase, while the opposite occurred for the amorphous one. The trend of the water contact angle (WCA) clearly indicates that alkali is more effective than cutinase in enhancing hydrophilicity of PET films and that the effect is stronger on amorphous than on crystalline films. The values of WCA correlate well with the FTIR indexes calculated from the spectra of hydrolyzed crystalline PET films. The mechanism of the surface hydrolysis of PET by alkali and cutinase is discussed. |
| |
Keywords: | Poly-(ethylene terephthalate) (PET) Cutinase Alkali FTIR spectroscopy Water contact angle |
本文献已被 ScienceDirect 等数据库收录! |
|