Research progress of novel bio-based plasticizers and their applications in poly(vinyl chloride)

Plasticized polyvinyl chloride (PVC) has been widely used in the world. Petroleum-based plasticizers especially phthalates have been the most common plasticizers used in PVC. However, the global petroleum resources are becoming scarce gradually, and the hygienic requirements for plasticizers are increasing. Owing to the negative impact of petroleum-based plasticizers on human health and the environment, their use has been restricted in the USA, the European and so on. Biomass renewable resources have wide range of sources and low prices, and the chemicals obtained from them have various structures, which can provide a huge platform to design novel PVC plasticizers with the aim of replacing traditional phthalate plasticizers. Many bio-based PVC plasticizers, such as vegetable oil-based plasticizers, cardanol-based plasticizers, lactic acid-based plasticizers, waste cooking oil-based plasticizers, polyester plasticizers, hyperbranched plasticizers and so on, have been extensively studied. We have reviewed recent research progress on different types of novel bio-based PVC plasticizers and assorted them by raw materials and chemical structure. Through in-depth analysis of the relationship between the chemical structure and the plasticizing performance, the efficiency of plasticizers may be predicted before they have been designed. This review will be beneficial for the development of bio-based plasticizers by pointing out the research and application direction.