Accurate Evaluation of Dynamics and Specific Interactions in PLA/TiO2 Nanocomposites
| Autor: | Dania Olmos, J. Teno, Edwin A Segura González, Javier González-Benito |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España) |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | e-Archivo. Repositorio Institucional de la Universidad Carlos III de Madrid instname e-Archivo: Repositorio Institucional de la Universidad Carlos III de Madrid Universidad Carlos III de Madrid (UC3M) |
| DOI: | 10.36959/562/615 |
| Popis: | Near infrared spectroscopy in the transmission mode was used to study the effect of the presence of TiO2 nanoparticles on the dynamics of Polylactic Acid (PLA) in PLA/TiO2 nanocomposites. The variation of IR absorbance of certain bands, the average energy of those absorptions (< ν >, cm-1) and two-dimensional Infrared (2D IR) correlation spectroscopy as a function of temperature and TiO2 content (0, 1, 5 and 10% wt) were used. Thermal transitions associated to the glass transition (64 ℃) and cold crystallization temperatures (123 ℃) are clearly identified from the analysis of integrated absorbance of bands at 4770 and 4725 cm-1, assigned to amorphous phase, as they were more sensitive to temperature changes. The band at 4440 cm-1, related with the formation of crystalline regions, showed a better definition of the thermal transitions as well as the bands at 4307 and 4255 cm-1 associated to the combination of C-H wagging modes showed sharp changes, suggesting that transitions occur due to backbone conformational changes. The evolution of integrated absorbance of different bands in PLA-TiO2 nanocomposites as a function of temperature, seem to point out the presence of specific interactions between the C = O group and TiO2 nanoparticles. This effect is observed up to 1% wt whereas for higher loadings it is not possible to detect thermal transitions due to the scattered of the data for higher loadings of particles. Authors gratefully acknowledge financial support from the Ministerio de Ciencia e Innovación (project MAT2010-16815) and the Ministerio de Economia y competitividad (Project MAT2014-59116-C2-1-R) and project number 2011/00287/002. |
| Databáze: | OpenAIRE |
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