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- Title
Thermal and mechanical properties of nanocomposites based on a PLLA- b-PEO- b-PLLA triblock copolymer and nanohydroxyapatite.
- Authors
Loiola, Lívia M. D.; Fasce, Laura A.; da Silva, Laura C. E.; Gonçalves, Maria C.; Frontini, Patricia M.; Felisberti, Maria I.
- Abstract
ABSTRACT Composites which combine biocompatible polymers and hydroxyapatite are unique materials with regards to their mechanical properties and bioactivity in the development of temporary bone-fixation devices. Nanocomposites based on a biocompatible and amphiphilic triblock copolymer of poly( l-lactide) (PLLA) and poly(ethylene oxide) (PEO) -PLLA- b-PEO- b-PLLA- and neat (nHAp) or PEO-modified (nHAp@PEO) hydroxyapatite nanoparticles were prepared by dispersion in benzene solutions, followed by freeze-drying and injection moulding processes. The morphology of the copolymers of a PEO block dispersed throughout a PLLA matrix was not changed with addition of the nanofillers. The nHAp particles were spherical and, after modification, the nHAp@PEO nanoparticles were partially agglomerated. In the nanocomposites, these particles characteristics remained unchanged, and the nHAp particles and nHAp@PEO agglomerates were uniformly dispersed through the copolymer matrix. These particles acted as nucleating agents, with nHAp@PEO being more efficient. The incorporation of nHAp increased both the reduced elastic modulus (∼22%) and the indentation hardness (∼15%) in comparison to the copolymer matrix, as determined by nanoindentation tests, while nHAp@PEO addition resulted in lower increments of these mechanical parameters. The incorporation of untreated nHAp was, therefore, more beneficial with regards to the mechanical properties, since the amphiphilic PLLA- b-PEO- b-PLLA matrix was already efficient for nHAp nanoparticles dispersion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44187.
- Subjects
NANOCOMPOSITE materials; AMPHIPHILES; COPOLYMERS; ETHYLENE oxide; BENZENE
- Publication
Journal of Applied Polymer Science, 2016, Vol 133, Issue 44, pn/a
- ISSN
0021-8995
- Publication type
Article
- DOI
10.1002/app.44187