Design and Synthesis of a Novel Mannitol Fumarate Ester-Based Lanthanum Alkoxide as Multifunctional Additive for Polyvinyl Chloride

This work aims to design and develop friendly multifunctional heat stabilizers with sterilization, and lubrication for widely used polyvinyl chloride (PVC). Herein, a novel multifunctional antimicrobial thermal stabilizer, mannitol fumarate ester-based lanthanum alkoxide (MFE-La) was successfully obtained, and fully characterized. The thermal stability and processing performance of PVC were evaluated via antibacterial, hemolysis study, conductivity measurement, thermal aging, torque rheology experiments, and the mechanical tensile test. Antibacterial experiments showed that MFE-La has a bactericidal rate of more than 99% against Escherichia coli and Staphylococcus aureus; and antifungal experiment results also showed that MFE-La also provides the possibility of antifungal effects on PVC. The hemolysis experiment results showed that the hemolysis rate of MFE-La on red blood cells is about 4%. In addition, oven aging, conductivity, and UV–vis spectra measurement verified that MFE-La can significantly improve the initial and long-term thermal stability of PVC. Mechanistic studies showed that MFE-La has a good ability to absorb HCl and replace allyl chloride. The mechanical tensile test on the tensile strength of PVC showed that the elongation at break of PVC after adding MFE-La is significantly increased, indicating that MFE-La can improve the softness and elasticity of PVC. Torque rheology experiments verified that MFE-La has good plasticizing properties and lubrication properties. MFE-La has multiple functions such as retarding PVC thermal degradation, lubrication, plasticization, and sterilization, and has considerable potential in medical supplies and biomedicine application prospects.