Preparation and thermal stability of bio-based Na/Zn composite liquid stabilizers for poly(vinyl chloride)

•Liquid Na(L-Na-MAME and L-Na-DFA), liquid Zn(L-Zn-MAME and L-Zn-DFA,), and Na/Zn composite liquid stabilizers(LTS-Na/Zn-MAME and LTS-Na/Zn-DFA) for poly(vinyl chloride)(PVC) were successfully synthesized from the adduct of maleic anhydride and methyl eleostearate (MAME) and dimer fatty acid (DFA), respectively.•L-Na-MAME and L-Na-DFA both well synergistically interact with CaSt2/ZnSt2 to affect the initial and long-time heat stability.•LTS-Na/Zn-MAME can more effectively enhance the primary coloring of PVC.•The bio-based Na/Zn composite liquid stabilizers for PVC can fully or partially replace the general calcium zinc stearate composite heat stabilizer and other heat stabilization products.