Impact of Natural and Synthetic Antioxidants on The Stability of High-Density Polyethylene

High-Density Polyethylene (HDPE) has been playing a crucial role in the life of every human being, due to its properties, such as chemical resistance, lightweight, and ease of forming, among others. Its usage ranges from bottles for beverages and other liquids, pipes, wire and cable insulations, and prosthetics. As it undergoes several thermal cycles during its life cycle, it is important to maintain its qualities even after undergoing thermal and thermo-oxidative degradations. Here, various dosages of synthetic (Irganox 1010) and natural (vitamin E) antioxidants are added into HDPE formulations to study their impacts on HDPE stability. The antioxidants are mixed physically with HDPE before the mixtures are melt-mixed three times to represent their life cycles. Samples are taken after each time and used to analyze the molecular weight distribution, rheological behavior, mechanical properties, and thermal stability. The results show that vitamin E is superior to Irganox 1010 in those tests, as vitamin E performance exceeds Irganox 1010, even in lesser doses. The only drawback of using vitamin E is the yellow color caused by it, which may necessitate another additive to enhance the color stability of HDPE in color-sensitive applications.