Design and Development of Low-Density Polyethylene Composites Reinforced with Coconut Fiber for Enhanced Material Properties for Composite Structures

The increasing demand for sustainable and lightweight materials in various industries has driven the exploration of natural fiber-reinforced polymer composites. This study focuses on the design and development of low-density polyethylene (LDPE) composites reinforced with coconut fiber, aiming to enhance material properties for use in composite structures. Coconut fiber, an abundant and eco-friendly material, was chosen as reinforcement due to its favorable mechanical properties, biodegradability, and cost-effectiveness. LDPE, a widely used thermoplastic, was selected as the matrix material for its low density, excellent processing capabilities, and compatibility with natural fibers. The composite materials were fabricated using a compression molding technique, incorporating coconut fiber in varying weight percentages (0%, 20%, 40%, 60%, and 80%). Key physical and mechanical properties, including tensile, flexural, and impact strengths, were assessed to evaluate the performance of the composites. The results demonstrated that composites with 40 wt% and 60 wt% fiber loading exhibited optimal tensile and impact strengths, making them suitable for structural applications requiring enhanced mechanical performance. Conversely, composites with 20 wt% fiber content displayed suboptimal properties due to inadequate fiber-matrix bonding, highlighting the importance of achieving proper interfacial adhesion. Microstructural analysis using Scanning Electron Microscopy (SEM) revealed a heterogeneous distribution of fibers within the LDPE matrix, with noticeable weak interfacial bonding at higher fiber loadings. Moisture absorption tests showed that composites with lower fiber content had minimal water uptake, while those with higher fiber loadings experienced significant absorption and swelling, limiting their use in water-based environments. However, the composites were found to be suitable for non-structural applications in moist conditions, such as partitions, false ceilings, roof tiles, and door and window frames. This study demonstrates the potential of coconut fiber-reinforced LDPE composites as lightweight, sustainable alternatives for non-structural and low-strength applications. The findings provide valuable insights into the optimization of fiber loading and processing techniques to achieve desirable mechanical and physical properties. Furthermore, the research underscores the role of natural fibers in promoting environmentally friendly materials and reducing waste in polymer composite production.