Epoxy materials have attracted attention for many applications that require fireproof performance; however, the utilization of hazardous reagents brings about potential damage to human health. Eugenol and cardanol are renewable, harmless resources (according to ECHA) that allow the achievement of synthesis of novel phosphorylated epoxy monomers to be used as reactive flame retardants. These epoxy building blocks are characterized by ¹H NMR and ³¹P NMR (nuclear magnetic resonance) and reacted with a benzylic diamine to give bio-based flame-retardant thermosets. Compared to DGEBA (Bisphenol A Diglycidyl Ether)-based material, these biobased thermosets differ by their cross-linking ratio, the nature of the phosphorylated function and the presence of an aliphatic chain. Eugenol has led to thermosets with higher glass transition temperatures due to a higher aromatic density. The flame-retardant properties were tested by thermogravimetric analyses (TGA), a pyrolysis combustion flow calorimeter (PCFC) and a cone calorimeter. These analyses demonstrated the efficiency of phosphorus by reducing significantly the peak heat release rate (pHRR), the total heat release (THR) and the effective heat of combustion (EHC). Moreover, the cone calorimeter test exhibited an intumescent phenomenon with the residues of phosphorylated eugenol thermosets. Lastly, the higher flame inhibition potential was highlighted for the phosphonate thermoset.

The facile one-pot, two-step synthesis of a new bio-sourced monomer derived from cardanol and its radical aqueous miniemulsion polymerization are presented.

A recently revisited biobased styrenic monomer, acetyl-protected 4-vinylguaiacol (AC4VG), was used for the synthesis of partially biobased, functional core–shell polymers. P(S-co-BA)@PAC4VG and PBA@PAC4VG latex particles with a PAC4VG shell were prepared using a two-step seeded radical emulsion polymerization process. The P(S-co-BA) and PBA seed particles were synthesized first, and the AC4VG monomer was subsequently added as a pre-emulsion over time. The aqueous emulsion polymerizations were carried out at 10 wt% solids at 80 °C using ammonium persulfate as a radical initiator and sodium dodecyl sulfate as a surfactant. These polymerizations resulted in colloidally stable latexes with high monomer conversions (>95%). The resulting particles were 80–90 nm in diameter (intensity-average) and TEM observations revealed core–shell and partially encapsulated particle morphologies. Up to 70% of the acetoxy groups of PAC4VG in the P(S-co-BA)@PAC4VG latex were deprotected under mild basic conditions over 18 hours to produce core–shell polymers decorated with phenolic functions on their surface. This deprotection procedure did not adversely affect the particle size or colloidal stability of the latex. Finally, partially biobased phenolic networks (phenolic resins) were produced from these functional core–shell particles by crosslinking with glyoxal, a naturally-sourced dialdehyde.