Morphology and film performance of phthalate-free plasticized poly(vinyl chloride) composite particles via the graft copolymerization of acrylate swelling flower-like latex particles

This study reports an intriguing preparation of a nontoxic and phthalate-free polyacrylate/poly(vinyl chloride)-swollen then grafted-polyacrylate (PBA/PVC-sg-PBA) for the production of flexible PVC by means of a multistage emulsion polymerization. Flower-like PBA/PVC composite particles with rich hydrophilic groups and functional end groups were first synthesized through the seeded emulsion polymerization of poly(butyl acrylate) (PBA), vinyl chloride (VC), 3-(trimethoxysilyl) propyl methacrylate (MPS), and allyl methacrylate (AMA), and then the anisotropic PBA/PVC composite particles were used as seeds to prepare PBA/PVC-sg-PBA composite particles. PBA is biologically safe without producing an acute toxicity response. This formation process was studied in detail, and the effects of the BA/(PBA/PVC) feed weight ratio on the PBA/PVC-sg-PBA composite particle morphology and mechanical properties of the prepared film materials were investigated. Scanning electron microscopy (SEM) observations indicated that the content of MPS in the PBA/PVC seeds was crucial to control the morphologies of the flower-like PBA/PVC composite particles. Transmission electron microscopy (TEM) illustrated that the PBA was uniformly dispersed in the PBA/PVC particles to form an interpenetrating network layer. Dynamic mechanical analysis (DMA) revealed that the compatibility between PBA and PVC was well improved with increasing PBA content. The flexibility of phthalate-free PBA/PVC-sg-PBA was comparable to the corresponding performance of a commercial PVC/DOP mixture, and its stretchability was superior to the PVC/DOP system.