Recycled polyethylene/polycarbonate blends compatibilized with oxidized polyethylene/CaCO3

Polyethylene (PE) and polycarbonate (PC) are not thermodynamically miscible, and they tend to be phase-separated during melt-processing, because of significant incompatibility in structures and properties. Interestingly, minerals such as CaCO3 are used in PE-based supermarket bags for improving surface characteristics. In this study, recycled low-density polyethylene (LDPE) and PC resins are melt-blended at 50/50 wt%, without and with oxidized polyethylene (OPE) as a compatibilizer. A parallel experiment is conducted with 50/50 blends of virgin LDPE and PC resins. Various characteristics such as tensile, viscoelastic, melt-flow, and phase morphology of the materials are analyzed. The 50/50 blend of recycled LDPE/PC blend shows an average tensile strength of 15 MPa, which increases to 24 MPa on the addition of 5 wt% OPE, where total recycled content is 95 wt% including 15 wt% CaCO3. Notably, the presence of CaCO3-based filler in recycled LDPE has a profound effect in improving the mechanical performance of the materials.