Artículos de revistas
Influence of amorphous block on the thermal behavior of well-defined block copolymers based on e-caprolactone
Fecha
2013-05Registro en:
Ninago, Mario Daniel; Satti, Angel Jose; Ciolino, Andrés Eduardo; Villar, Marcelo Armando; Influence of amorphous block on the thermal behavior of well-defined block copolymers based on e-caprolactone; Springer; Journal of Thermal Analysis and Calorimetry; 112; 3; 5-2013; 1277-1287
1388-6150
1572-8943
Autor
Ninago, Mario Daniel
Satti, Angel Jose
Ciolino, Andrés Eduardo
Villar, Marcelo Armando
Resumen
In this work, we studied the thermal characterization of block copolymers based on ε-caprolactone. The copolymers were obtained by anionic polymerization techniques, using different co-monomers such as styrene (S) and dimethylsiloxane (DMS). Synthesized copolymers were characterized by H-nuclear magnetic resonance, size exclusion chromatography, and Fourier transform infrared spectroscopy. Isothermal crystallization was performed by differential scanning calorimetry (DSC), and Avrami’s theory was employed in order to obtain kinetics parameters of interest, such as the half-life for the crystallization process (t1/2), the bulk crystallization constant (k), and the Avrami’s exponent (n). The spherulitic growth was measured by polarized optical microscopy in order to determine the crystallization behavior. Poly(ε-caprolactone) block (PCL) crystallization was analyzed by considering the physico-chemical characteristics of the neighboring block, PS or PDMS. The chemical nature of the neighbor block in the PCL-based copolymer affects the kinetics parameters of Avrami’s equation, as can be deduced by comparing the values obtained for pure PCL and the studied block copolymers. On the other hand, the apparent thermal degradation activation energies Ead for PCL and block copolymers were determined by Ozawa’s method. The incorporation of PDMS instead of PS improves the stability of the resulting copolymer, as it was observed by thermogravimetric analysis.