Mechanical Engineering
Graduate Seminar
NOTICE OF 1st PhD SEMINAR PRESENTATION
CANDIDATE: Sajjad Dehghanpour
DEGREE SOUGHT: PhD
DATE: 7/11/2025
TIME: 11:30am
PLACE: Room 1102 CEI
TITLE: Analyzing the Impact of Lignin Additives on the Mechanical Performance of Glass/PP Long Fibre Thermoplastics
Abstract
This study examined long-fibre thermoplastics (LFTs) with 30% glass fibre and varying lignin bio-filler content (0%, 14%, 21%) using direct inline compression moulding. Samples cut from charge and flow regions were tested in four directions (0°, ±45°, 90°) to assess anisotropy. At low strain rates, tensile strength dropped from ~100 MPa (0% lignin) to ~70 MPa (21% lignin), while 14% lignin showed intermediate results. Shear strength remained stable at 14% but declined ~10% at 21%. At high strain rates (200 s⁻¹), tensile strength increased significantly across all samples. SEM analysis revealed more fibre pull-out and matrix–fibre debonding with higher lignin content, especially at 21%, indicating weaker interfacial bonding. Tensile strength varied with orientation, lowest at 90° and highest at 0°.