Effect of Hydroxyapatite Particle Size on Mechanical and Thermal Properties of
FDM
Printed
PEEK
Composites
Justy N. Francis, Ananya Chattree, Mrityunjay Doddamani, Indranil Banerjee, Ankita Chugh, Jaiveer Singh ABSTRACT
Polyetheretherketone (PEEK) is FDA‐approved and bioinert, which has prompted researchers to modify this nature by incorporating bioactive inorganic fillers, mainly hydroxyapatite (HA). This study compares and establishes a correlation between particle size (nano vs. micro) of hydroxyapatite and its impact on the thermal and mechanical properties of PEEK‐HA polymer composites. Thermal analysis reveals a slight decrease of 2°C–4°C in the glass transition and melting temperatures of the HA‐incorporated PEEK samples. Tensile and flexural tests demonstrate that the size of HA significantly influences the mechanical properties, with nano‐hydroxyapatite (nHA) PEEK exhibiting superior performance compared to micro‐hydroxyapatite (mHA). On evaluating the ultimate tensile strength, PEEK‐nHA (PnH) is 28.09% higher than PEEK‐mHA (PmH), and the tensile modulus of PnH is 17.67% higher than PmH. A similar trend is seen for flexural strength, where PnH depicts 19.87% higher flexural strength than PmH. FE‐SEM fractography of the samples reveals that mHA particles have a greater impact on sample failure. The results together imply that nHA is more suitable than mHA when used as a filler particle for creating polymer composites with desirable properties. This study offers a thorough insight into the performance and suitability of these polymer composites for patient‐specific implants in load‐sharing applications.