The Effect of Annealing Treatments on Spherulitic Morphology and Physical Ageing on Glass Transition of Poly Lactic Acid PLLAReportar como inadecuado




The Effect of Annealing Treatments on Spherulitic Morphology and Physical Ageing on Glass Transition of Poly Lactic Acid PLLA - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Spherulitic morphology of pure poly lactic acid PLLA PLLA have investigated after thermal annealing. The morphology of spherulite of pure poly lactic acid PLLA PLLA have investigated after thermal annealing. The effect of both annealing temperature and crystallization temperature on the formation of cracks was described by polarized optical microscope POM. Non banded spherulite fibrils with cracks was detected in PLLA film after annealing at 160°C 180 min. and isothermal crystallization temperatures at 140°C and 150°C. With increasing temperature after annealing treatment the size of spherulite is increased and more cracks are formed. The maximum growth rate of spherulites was found at 130°C. The physical ageing was carried out by annealing the PLLA sample at room temperature for several annealing time ta from 0 h to 720 h. The enthalpy relaxation has been studied by differential scanning calorimetry DSC through analysis of the endothermic peak of glass transition temperature, which increased and shifted towards higher temperature as the annealing time increased.

KEYWORDS

Poly Lactic Acid PLLA, Morphology, Non-Banded Spherulites, Annealing, Polarized Optical Microscopy, Physical Ageing

Cite this paper

E. Mohamed -The Effect of Annealing Treatments on Spherulitic Morphology and Physical Ageing on Glass Transition of Poly Lactic Acid PLLA,- Materials Sciences and Applications, Vol. 2 No. 5, 2011, pp. 439-443. doi: 10.4236-msa.2011.25058.





Autor: El-Hadi Ahmed Mohamed

Fuente: http://www.scirp.org/



DESCARGAR PDF




Documentos relacionados