The search for innovative and cost-effective flame-retardant polymers is attracting increasing interest in both the academics and industrial community. In this work, flame-retardant polymers with high performance are developed through a monomer-to-polymer strategy. Specifically, biobased N–P synergistic vanillin-based acrylate monomers (MAPDVAs) are designed and synthesized, which are then polymerized via reversible addition–fragmentation chain transfer (RAFT) polymerization to obtain a biobased polymer, namely, PMAPDVA. The obtained PMAPDVA (Mn,GPC = 39100 g/mol) has a high residual carbon content of about 42.0 wt % at 800 °C. The peak heat release rate (PHRR) of PMAPDVA is only 62.0 W/g in a micro calorimeter (MCC) test, confirming excellent flame-retardant efficiency. The PHRR and the total heat release rate (THR) of poly 2-ethylhexyl acrylate (2-EHA) decreased by 33.8% and 42.7%, respectively, when 30.0 mol % MAPDVA was copolymerized. In addition, the copolymer coatings display light transmission more than 80% in the range of 380–780 nm, indicating fine transparency of the copolymer and satisfying compatibility of PMAPDVA. Finally, scanning electron microscopy (SEM) and thermogravimetric analysis infrared (TGA-IR) are applied to explore the flame-retardant mechanism of the resultant polymers. This work provides a key clue for the preparation of flame retardants from natural products.
Li et al. (Mon,) studied this question.