INEB
INEB
TitleStructure development and control of injection-molded hydroxylapatite-reinforced starch/EVOH composites
Publication TypeJournal Article
1997
AuthorsReis, RL, Cunha, AM, Allan, PS, Bevis, MJ
JournalAdvances in Polymer TechnologyAdv Polym Technol
Volume16
Issue4
Pagination263 - 277
Date Published1997///
07306679 (ISSN)
Biodegradation, Composition effects, Compounding (chemical), Copolymers, Extrusion molding, hydroxyapatite, Injection molding, Microstructure, Molecular orientation, Phosphate minerals, Polymer blends, Polyvinyl alcohols, Reinforced plastics, Rotating drum extrusion, Starch, Twin screw extrusion
This article reports on the development of novel composites of starch-based polymers reinforced with hydroxylapatite (HA). Two different grades of blends of starch and ethylene vinyl alcohol copolymers were reinforced with up to 30% (wt) of sintered and nonsintered HA. The initial compounding stage was carried out either in a rotating drum or by twin-screw extrusion (TSE). Compounds were injection molded using both conventional molding and a shear-controlled orientation in injection molding (Scorim) technique. It was possible to obtain composites with very good mechanical properties, approaching those of cortical bone. The best results were achieved for 30% sintered HA composites processed by TSE and Scorim, due to the in situ formation of HA fibers, and the development of molecular orientation and more compact microstructures in the moldings. This was confirmed by SEM analysis of the fracture surfaces, x-ray diffraction, and Raman spectroscopy. The biodegradability of the composites was also assessed and was found to be faster than that of the matrix. © 1997 John Wiley & Sons, Inc.
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