Characterization and thermal degradation of poly(d,l-lactide-co-glycolide) composites with nanofillers

• Published in: Polymer engineering and science Vol. 53; no. 7; pp. 1414 - 1429
• Main Authors: Palacios, Jordana, Albano, Carmen, González, Gema, Castillo, Reina Verónica, Karam, Arquímedes, Covis, María
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.07.2013; Wiley; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Chemical properties; Composite materials; Composites; Composition; Copolymers; Decomposition (Chemistry); Differential scanning calorimetry; Dispersions; Exact sciences and technology; Forms of application and semi-finished materials; Hydroxyapatite; Identification and classification; Lactic acid; Morphology; Nanoparticles; Nanotubes; Polymer industry, paints, wood; Polymeric composites; Spectrum analysis; Storage modulus; Technology of polymers; Thermal degradation; Thermal properties; Venezuela; Lactone copolymer; Storage modulus; Reaction order; Carbon nanotubes; Mechanical properties; Hydroxyapatite; Experimental study; Glass transition temperature; Composite material; Thermal stability; Surface treatment; Thermal properties; Morphology; Concentration effect; Nanocomposite; Activation energy; Thermal degradation; Rheological properties
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.23396

Chemical and thermal characterization of poly(d,l‐lactide‐co‐glycolide) (PLGA) composites filled with hydroxyapatite (HA) or carbon nanotubes (CNT) were evaluated by infrared spectroscopy, differential scanning calorimetry, thermogravimetry, and dynamic–mechanical–thermal analysis. The morphology and distribution of the nanoparticles were studied by transmission electron microscopy. The composites were prepared by solvent casting using 30% HA or 1, 3, and 5% of pristine and functionalized CNT as nanoparticles and PLGA 75:25 and PLGA 50:50 as copolymer matrix. The Coats–Redfern and E2 function methodologies were used to calculate the reaction order and the activation energy (Ea) of the thermal degradation process. It was found that the addition of nanoparticles increased the glass transition temperature (Tg) of the composites. Also, higher degradation temperatures and Ea values were obtained for PLGA–HA composites and compared with the neat copolymer, and the opposite behavior was exhibited by PLGA–CNT composites. The thermal and mechanical properties were highly dependent on the morphology and dispersion of the filler. The functionalization process of CNT promoted, to some extent, a better distribution and dispersion of CNT into the matrix, and these composites exhibited a slight enhancement on storage modulus. On the other hand, PLGA–HA composites showed a good dispersion but no improvement on the storage modulus below Tg. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers