Govindan, SrinivasanRamos, MaximianoAl-Jumaily, Ahmed2026-04-102026-04-102026-02-23ASME 2025 International Mechanical Engineering Congress and Exposition November 16–20, 2025. Memphis, Tennessee, USA. Volume 3: Advanced Materials: Design, Processing, Characterization and Applications; Advancements in Industry; Advances in Aerospace Technology ISBN: 978-0-7918-8934-39780791889343http://hdl.handle.net/10292/20901<jats:p>This research demonstrates that improving the characterization of Polyhydroxy butyrate (PHB) with 20 wt% Polycaprolactone (PCL), 5 wt% mixed Plasticizer (i.e., monomeric plasticiser (Triacetin 99%) and Polymeric plasticiser (Ultramoll IV), and nanomaterials, i.e., 1 wt% nanocellulose and 6 wt% nano clay, can improve the PHB characteristics for packaging purpose. Biodegradable polymer films were developed using injection moulding and hot-pressing methods, and characterised by tensile properties, water vapor barrier properties, and biodegradation properties in compost and seawater medium. The properties of the nanocomposite films compared to plasticised PHB-PCL 20 films show improved tensile strength, water vapour barrier properties, and slightly higher biodegradation rate with nanomaterials, though with reduced elongation at break. The nanocomposite films were also compared to neat PHB, with 1% nanocellulose (nCell) and 6% nano clay (nClay) providing higher tensile elongation (168% &amp; 146% higher), higher water vapor barrier properties / Lower water vapor transmission rate (46% &amp; 58% lower), and higher biodegradation in home compost (13 % &amp; 11% higher) and seawater medium (10% &amp; 11% higher). The research outcome shows that the high-performance PHB nanocomposite blend with 1% nanocellulose and 6% nano clay.</jats:p>Copyright © 2025 by ASME; reuse license CC-BY 4.040 Engineering4016 Materials Engineeringpolyhydroxy butyrate (PHB)polycaprolactone (PCL)nano compositetensile propertieswater vapor barrier propertiesbiodegradation propertiesConference ContributionOpenAccess10.1115/imece2025-168046