A targeted review of bio-derived plasticizers with flame retardant functionality used in PVC

For decades, a wide variety of products have benefitted from the use of flexible PVC, ranging from healthcare to cable to packaging & household items. The uniqueness of PVC rises from its growth as polymer from monomers and the final structure. Due to the presence of chlorine atoms, PVC is inherently flame retardant, but it cannot always meet all fire safety requirements and maintain a needed balance of properties. One approach to meet this balance of properties is to incorporate flame retardant functionality directly into the plasticizer that is added to PVC. However, the toxicity of current plasticizers has motivated a focus on bio-based plasticizers. In flexible PVC products where flame retardancy is necessary, reports have begun to appear involving bio-plasticizers where flame retardant functionality is included. This focused review presents current research in the flexible PVC field emphasizing development of bio-plasticizers and flame retardants, and an analysis of examples of bio-plasticizers, chemical structures, and effects on flame retardancy. The review concludes with a perspective on the main challenges and future research directions for this exciting fire research field.