Comparative Performance Evaluation of Smooth and Textured White Geomembranes Under UV Exposure

High-density polyethylene (HDPE) geomembranes are widely utilized in environmental protection projects, where they are produced in various colours to meet specific technical requirements. The addition of colour to these geomembranes involves the use of additives other than carbon black, which is traditionally employed for its cost-effectiveness and superior Ultraviolet (UV) protection properties, giving HDPE geomembranes their characteristic black colour. This study examines the degradation of smooth and textured HDPE geomembranes with a white surface. These geomembranes, with a nominal thickness of 1.00 mm, were manufactured using both flat die and round die processes and subjected to accelerated UV aging for 500 and 1000 hours, with the white surface exposed. Physical and mechanical tests were conducted to assess the performance of the geomembranes post-exposure. Initial High Load Melt Index (HLMI) and Low Load Melt Index (LLMI) values indicate differences in manufacturing processes and composition despite both geomembranes achieving similar HLMI values after 500 hours of UV exposure. The textured geomembrane exhibited a significant reduction in strain at break, likely linked to its high standard deviation, a typical characteristic of textured geomembranes. Despite these differences, both geomembranes subjected to accelerated ageing exceeded the minimum tensile property requirements specified by the GRI-GM13.