Mechanical Properties of Recycled Polyethylene Terephthalate/ Polycarbonate/ Methylene Diphenyl Diisocyanate (r-PET/PC/MDI) Composite

Abstract

The present study aimed to investigate the mechanical properties of recycled Polyethylene Terephthalate (r-PET) and Polycarbonate (PC) composites, with the incorporation of Methylene Diphenyl Diisocyanate. The primary objective was to identify the optimal composition for achieving superior mechanical performance. The composition under examination comprises four ratios, namely r-PET/PC1 (20/80), r-PET/PC2 (40/60), r-PET/PC3 (60/40), and r-PET/PC4 (80/20), expressed as weight percentages. The concentration of MDI utilized in the experiment was maintained at a constant level of 0.9% based on weight. The r-PET/PC/MDI composite underwent blending using a Brabender Plastograph prior to being introduced into the injection moulding process for sample production. The mechanical properties can be ascertained through the analysis of data acquired through mechanical testing, encompassing Tensile tests, Flexural tests, and Impact tests. The findings indicate that there is an inverse relationship between the percentage of r-PET in the blend and the tensile strength, with an increase in r-PET resulting in a decrease in tensile strength. Conversely, there is a positive relationship between the percentage of r-PET and Young's modulus, with an increase in r-PET leading to an increase in Young's modulus. The flexural strength and flexural modulus exhibit variations as the r-PET content increases in the r-PET/PC/MDI blend. Lastly, it can be observed that the impact strength reduces as the proportion of r-PET in the blend increases. The findings of this experiment indicate that the composition of r-PET/PC1 yielded the most favourable results. The composition under investigation demonstrated the greatest recorded tensile strength, measuring 22.30 MPa, as well as the second highest flexural strength, measuring 119.77 MPa. However, the impact strength of r-PET/PC1 exhibited the greatest value compared to the other samples, measuring 0.32J. In summary, the findings indicate that the mechanical characteristics of the r-PET/PC/MDI mix can be improved through the optimization of PC content, hence enhancing the features of r-PET.