Interaction Effect of Scomberomorus Guttatus-Derived Hydroxyapatite and Montmorillonite on the Characteristics of Polylactic Acid Blends for Biomedical Application

The objective of this work was to investigate the effect of Mackerel-derived hydroxyapatite (MHAp) and native montmorillonite (MMT) on the mechanical-physico properties of the polylactic acid (PLA) blends. Various amounts of MHAp (2 to 10 phr) and MMT (0 to 4 phr) were added into PLA matrix by using melt-blending method. The results of tensile test and X-ray diffraction analyses indicated that the reinforcing and nucleating effect of MHAp on PLA matrix has effectively improved the tensile strength and crystallinity of pristine PLA. The addition of MMT particles has significantly increased the mechanical strength but decreased the crystallinity of relevant PLA/MHAp composites, indicates the effective melt intercalation of PLA matrix into MMT interlayer space. The d-spacing of MMT deflection peak could be increased by further increasing of MMT loading from 2 to 4 phr in PLA/MHAp/MMT blends. This indicates the occurrence of PLA hydrolysis during melt compounding at higher MMT loading level, being supported by the FTIR analysis and the deterioration in morphological properties of PLA ternary composites. However, the hydrolytic degradation-induced increment of PLA functional groups for reaction with excessive amount MHAp could counterbalance the adverse effect of interfacial tension between PLA and MHAp (8-10phr) on mechanical properties.