Development Of Carbonated Hydroxyapatite/ Poly(L-Lactide)/ Poly(Vinyl Alcohol) Biocomposites.
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Date
2013-11
Authors
Chia Ching, Kee
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Nanosized B-type carbonated hydroxyapatite (CHA) was successfully
synthesized through nanoemulsion method, by both dropwise (DW) and direct
pouring (DP) techniques. The CHA powders obtained by DP method contained
higher CO3
2- content with smaller near-spherical size, as compared to the one by DW
with elongated shape. Moreover, the CHA particle size was found to decrease with
increasing CO3
2- content, with maximum CO3
2- substitution of 14 wt%. Annealing
followed by carbonation at cooling stage on CHA was carried out in the range of
300 900 °C. The optimum temperature of 700°C was determined from the adequate
B-type CO3
2- content retained and improved crystallinity of the annealed powder. In
the biocomposite fabrication of CHA with poly(L-lactide) (PLLA) and/or poly(vinyl
alcohol) (PVA), hydrogen bonding was deduced to form between hydroxyl group of
CHA and carbonyl of PLLA, while no interaction was observed between CHA with
PVA. When CHA/PLLA/PVA biocomposites were fabricated, PLLA served as
coupling agent which bridged CHA and PVA via hydrogen bonding. From the
mechanical aspect, diametral tensile strength (DTS) of the biocomposites was found
to increase with increasing polymer loading and when PLLA was added instead of
PVA. Nevertheless, CHA/PLLA/PVA biocomposites exhibited comparable DTS
value at lower polymer content. In terms of bioactivity, the CHA/PLLA/PVA
biocomposite showed better resorption rate and apatite formation as compared to
CHA/PLLA, while CHA/PVA was low with highest weight loss in simulated body
fluid.
Description
Keywords
Development Of Carbonated , Hydroxyapatite/ Poly