Surface-Functionalized Layered Double Hydroxides (LDHs) Nanoplatelets for Enhanced Thermal Stability of Plasticized Polyvinyl Chloride (PVC) films

Surface and interfacial engineering of additives is crucial for enhancing the compatibility between inorganic additives and polymer matrices. Thermal stabilizers are particularly prevalent in polyvinyl chloride (PVC) compounding. Recently, layered double hydroxidehydroxide (LDH) structures have been explored as a new class of efficient and environmentally-friendly stabilizers. This study uses oleic acid (OA) as a bio-sourced surface-active agent for improved compatibility between MgAlZn-CO3 LDH and the PVC matrix. Scanning electron microscopy (SEM) results indicated that OA substantially influences the distribution of LDHs throughout PVC matrix. Additionally, Raman spectroscopy confirmed that the incorporation of OA enhances the HCl absorption capability of LDHs, leading to an over two-fold increase in the static thermal stability of PVC. Correspondingly, color stability of PVC compounds with the modified LDH also improves significantly. The surface-functionalized LDH developed in this work exhibits tremendous potential as a highly potent and yet environmentally-friendly stabilizer for PVC processing as well as for PVC recycling and its circular economy.