Utilisation of recycled thermoplastics sourced from rejected-unused disposable diapers as polymer blends

Abstract

The blending of two or more thermoplastics could produce polymer blends, which are preferable compared to developing a new type of plastic. This paper presents the study on the utilisation of recycled thermoplastic polymers which are recovered from rejected unused disposable diapers. The aim of study is to characterise the effect of manufacturing temperature on the tensile and morphological properties of recycled plastic blend. Besides that, the polymer blend sourced from virgin materials was also prepared to compare the properties. The recycled and virgin materials were blended by using an internal mixer with fixed parameters. Later, the blended materials were crushed and moulded using hot compression moulding with temperature variations of 180 °C, 190 °C and 200 °C. The tensile tests were conducted in accordance with the ASTM D638 using a universal testing machine, followed by scanning electron morphological analysis. The results showed that as temperature increases, tensile strength decreases and tensile strain increases for both recycle and virgin blends. Tensile strength and strain for the recycled blend were also lower than the virgin blend at all temperatures, due to low miscibility in the recycled blend compared to the virgin one. The low miscibility caused more macrophase separation and resulted in poor adhesion between the polymer components. Also, the increase of temperature caused the tensile modulus to be reduced for the recycled blend. Meanwhile for the virgin blend, the modulus reduced at 190 °C but increased suddenly at temperature of 200 °C.