Construction of enhanced self-plasticized PVC via grafting with bio-derived mannich base

Developing lauraldehyde-derived Mannich base grafted PVC materials (PVC-ML-g, g = 1, 2, 3, 4, where the lauraldehyde-derived Mannich base is abbreviated as ML) via clean and efficient strategies is an effective way to resolve the increasing diseases in humans and environmental pollution caused by toxic dioctyl phthalate (DOP) traditionally used to plasticize PVC materials. Thus, in this study, the lauraldehyde-derived Mannich base, which contains both phosphate ester groups and highly flexible long carbon chains, was grafted onto PVC chains to efficiently plasticize PVC materials. The PVC-ML-g materials displayed a lower glass transition temperature than pure PVC and were comparable to conventional DOP plasticized PVC. The good plasticization behavior in the PVC-ML-3 materials was due to the simultaneous introduction of more ester groups and mobile, unentangled longer alkyl chains into the structure of PVC, which decreased the molecular interactions between the PVC chains. Moreover, the PVC-ML-g materials showed improved thermal stability and outstanding anti-migration ability because of the covalent bonds between PVC and lauraldehyde-derived Mannich base grafts.