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Characterization and thermal degradation of poly( d , l ‐lactide‐ co ‐glycolide) composites with nanofillers
Author(s) -
Palacios Jordana,
Albano Carmen,
González Gema,
Castillo Reina Verónica,
Karam Arquímedes,
Covis María
Publication year - 2013
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.23396
Subject(s) - materials science , composite material , differential scanning calorimetry , plga , dynamic mechanical analysis , glass transition , nanocomposite , nanoparticle , copolymer , thermogravimetry , dispersion (optics) , polylactic acid , lactide , polymer , carbon nanotube , composite number , chemical engineering , nanotechnology , physics , thermodynamics , optics , engineering
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 E 2 function methodologies were used to calculate the reaction order and the activation energy ( E a ) of the thermal degradation process. It was found that the addition of nanoparticles increased the glass transition temperature ( T g ) of the composites. Also, higher degradation temperatures and E a 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 T g . POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers