International Journal of Advanced Engineering Application

Mechanical, Thermal and Biodegradation Characteristics of Polylactic Acid Composites Reinforced with Hydroxyapatite Nanoparticles for Biomedical Scaffold Applications

Author(s):Rajesh Kumar , Suresh Chandra Mishra, Ananya Bhattacharyya

Affiliation: Department of Biomedical Engineering, Rajasthan Institute of Technology and Management, Jaipur, Rajasthan, India Department of Metallurgical Engineering, Assam Institute of Engineering and Applied Sciences, Guwahati, Assam, India

Page No: 56-63

Volume issue & Publishing Year: Volume 3, Issue 4, May 2026

Journal: International Journal of Advanced Engineering Application (IJAEA)

ISSN NO: 3048-6807

DOI:

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Abstract:
Polylactic acid (PLA) is one of the most widely investigated biodegradable polymers for tissue engineering scaffolds; however, its inherently brittle fracture behaviour, limited thermal stability above the glass transition temperature (Tg approximately 58–62°C), and insufficient osteoconductivity restrict its clinical applicability as a load-bearing bone scaffold. Incorporation of hydroxyapatite (HA, Ca10(PO4)6(OH)2) — the principal inorganic constituent of natural bone — as a nano-scale reinforcing filler has been proposed to simultaneously address these limitations through mechanical reinforcement, thermal stabilisation, and enhancement of bioactivity. Despite extensive literature on individual property improvements, systematic multi-variable investigations correlating processing parameters, filler surface modification strategy, filler loading fraction (5, 10, 15 wt%), and integrated mechanical-thermal-biodegradation performance under physiologically relevant conditions remain limited. This study fabricates PLA/HA nanocomposites by solvent casting followed by compression moulding, employing silane coupling agent (3-aminopropyltriethoxysilane, APTES) surface modification of HA to improve polymer-filler interfacial adhesion. Comprehensive characterisation includes uniaxial tensile testing at temperatures 25–120°C, three-point flexural testing, Charpy impact testing, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) of fracture surfaces, and in vitro biodegradation in simulated body fluid (SBF) over 180 days. PLA/10%HA achieves 21.5% improvement in tensile strength (55.6 vs 48.2 MPa), 25% improvement in flexural modulus (4.5 vs 3.6 GPa), and 12°C elevation of thermal onset degradation temperature relative to neat PLA. The 15%HA loading induces filler agglomeration that reduces elongation at break, identifying 10%HA as the optimal composition. Biodegradation rate in SBF decreases monotonically with HA content, consistent with HA’s role in reducing moisture uptake. FTIR and SEM confirm effective APTES-mediated interfacial coupling and homogeneous filler dispersion at 10%HA loading.

Keywords: polylactic acid, hydroxyapatite, nanocomposite, tissue engineering, scaffold, biodegradation, thermal analysis, TGA, DSC, FTIR, SEM, mechanical properties

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