Investigation of Mechanical Properties of Hemp Fiber‐Reinforced PC / PBT Thermoplastic Composites

The present work introduces a novel hemp fiber‐reinforced polycarbonate/polybutylene terephthalate (PC/PBT) composite with enhanced mechanical performance for high‐performance engineering applications. Composite samples with 10 wt.%, 20 wt.%, and 30 wt.% hemp fiber were fabricated under controlled production conditions, and their mechanical performance was systematically characterized with Shore D hardness measurements and three‐point bending tests. Hemp fiber‐reinforced PC/PBT composites were produced via melt mixing followed by controlled hot‐ and cold‐press molding. The flexural behavior of the fabricated composites was evaluated in terms of flexural strength, strain at maximum stress, elongation at fracture, and modulus of bending. The neat PC/PBT matrix was used as the reference material in performance comparisons and exhibited a flexural strength of 35.18 MPa and a modulus of bending of 1703.97 MPa. Increasing hemp fiber content resulted in higher calculated flexural strength and stiffness, together with reduced deformation capability. Notably, the 30 wt.% hemp composite sustained the same maximum load as neat PC/PBT despite its substantially smaller cross‐sectional area, indicating a favorable flexural response and improved structural rigidity. Experimental results demonstrate that hemp fiber‐reinforced PC/PBT composites hold significant potential as lightweight and sustainable engineering material candidates with promising structural performance. In addition to the experimental studies, the generated mechanical properties database provides reliable input parameters for finite element modeling, structural design optimization, and the development of advanced engineering components, particularly for lightweight defense and transportation applications.