Effects of Phosphite and Phenolic Antioxidants on the Mechanical and Optical Properties of Recycled Polycarbonate

Polycarbonate (PC) is an amorphous thermoplastic polymer with robust mechanical propertiesand good transparency. Due to the ever-increasing polycarbonate market, recycling thispolymer is an unavoidable reality. Nevertheless, recycling faces many impediments.Recycling-induced yellowness is one of the most important yet most stubborn phenomenonsduring recycling which negatively affects the optical properties and aesthetics ofpolycarbonate; thus limiting its applications. This research tried to improve the mechanical andoptical properties of polycarbonate recycled from CD by upcycling it. For this purpose, a kindof phosphite antioxidant, Irgafos ۱۶۸, was used, and its effects on the mechanical and opticalproperties of recycled polycarbonate were investigated, alone and with the combination of aphenolic antioxidant (Irganox ۱۰۱۰). According to the results, adding ۲۰۰۰ ppm of Irganox۱۶۸ prior to processing proved to be an effective solution in hindering yellowness while usinga mixture of both antioxidants was also useful. Using Irgafos ۱۶۸ alone and with Irganox ۱۰۱۰reduced Yellowness Index up to ۹۶ and ۸۱%, respectively. Also, the addition of ۲۰۰۰ ppmIrganox ۱۶۸, improves elastic modulus, elongation at break, and impact strength by ۱۹, ۲۸, and۲۸%, respectively. However, mechanical results show that using Irgafos ۱۶۸ in combinationwith Irganox ۱۰۱۰ has adverse effects on mechanical properties.

Keywords:

Plastics Recycling , Polycarbonate , Antioxidant , Upcycling