Recycling of Waste PET Plastic on Asphalt, by Using Application of Response Surface Methodology: Effect of Production Process Parameters

Abstract

Plastic, polymers of variable compositions have become object of common use and difficult to digest by micro-organisms, especially single-use plastic waste, such as polyethylene terephthalate (PET) water canisters. These polymers are source of environmental pollution. Therefore, it is important to manage theme in the good way to protect environment. In this study, different conditions of waste plastic PET (Polyethylene Terephthalate) recycling on asphalt were optimized. Response Surface Methodology (RSM) using the Doehlert experimental design has been employed in the optimization. The independent variables considered were bitumen (5-8%), PET (0-12%), Mixing temperature (150-160°C) and Mixing time (20-30min). Four-second order polynomial models were generated. The responses obtained by the models were well described as: specific density (Y.<SUB>SD</SUB>), penetrability (Y.<SUB>P</SUB>), softening point (Y.<SUB>SP</SUB>), and flash point (Y.<SUB>FP</SUB>) of the process with satisfactory fits in terms of absolute average deviation, bias factor and accuracy factor. The optimum responses were 1,04 as specificity gravity (Y.<SUB>SG</SUB>), 60*(1/10mm) as penetrability at 25°C, 100g and 5sec (Y.<SUB>P</SUB>), 50°C as softening point (Y.<SUB>SP</SUB>), and 242°C as flash point (Y.<SUB>FP</SUB>). The statistical relation between the four independent variables and the process responses were well described.