Vibration welding of PLA/PHBV blend composites with nanocrystalline cellulose

Abstract

Thermoplastic composites have garnered significant attention in various industries due to their exceptional properties, such as recyclability and ease of molding. In particular, biocomposites, which combine biopolymers with natural fibers, represent a promising alternative to petroleum-based materials, offering biodegradability and reduced environmental impact. However, there is limited knowledge regarding the efficacy of joining PLA/PHBV-based biocomposites modified with nanocrystalline cellulose (NCC) using vibration welding, which restricts their potential applications. This study demonstrates that vibration welding enables efficient bonding of PLA/PHBV composites with NCC, resulting in strong, biodegradable, and environmentally friendly materials. The investigation revealed that the addition of nanocrystalline cellulose (NCC) at 5, 10, and 15 wt.% significantly enhanced the strength of welded joints, with the highest strength achieved at 15% NCC content. Microstructural analysis using scanning electron microscopy (SEM) and deformation studies with digital image correlation (DIC) indicated that a higher NCC content led to greater local deformation, reducing the risk of brittle fracture. Mechanical hysteresis tests confirmed the composites’ favorable resistance to variable loads, highlighting their stability and energy dissipation capabilities. Optimization of welding parameters, such as vibration amplitude, welding time, and pressure, is crucial for achieving optimal mechanical performance. These findings suggest that PLA/PHBV composites modified with NCC can be utilized as durable and eco-friendly materials in various industries, including automotive and packaging. This research presents new opportunities for the development of biodegradable high-strength materials that can serve as alternatives to traditional plastics.