Synthesis of new flame-retardants by radical chain transfer copolymerization of glycidyl methacrylate and dimethoxy-phosphorylmethyl methacrylate

phosphorus flame retardants flax fabrics


R. Ménard, C. Negrell-Guirao, L. Ferry, R. Sonnier, G. David


European Polymer Journal, 57, 109-120


May 2014


We present a new and original approach to prepare flame retardants (FR) compounds. The strategy adopted consists first in synthesizing new reactive phosphorus-containing oligomers and then to chemically graft them to an epoxy network. These reactive FR compounds are synthesized by radical chain transfer copolymerization of dimethoxy-phosphorylmethyl methacrylate (MAPC1) with glycidyl methacrylate (MAGLY). Reactivity ratios were determined rMAPC1 = 0.78 and rMAGLY = 1.28 at 80 °C. The molecular weight of all the (co)oligomers was calculated by steric exclusion chromatography between 1000 and 3000 g mol−1. The synthesized FR were incorporated into an epoxy matrix as reactive binders. Then these formulations were cured at high temperature and the cross-linking densities were determined by DSC. The thermal properties and burning behaviors of cured epoxy resins were investigated. Thermogravimetric analysis showed a small decrease in thermal stability accompanied by a 50% increase in char yield. Pyrolysis combustion flow calorimetry (PCFC) was also used to evaluate the flammability of the modified epoxy resin. A significant decrease in peak of heat release rate (pHRR) and total heat release (THR) was observed. Indeed, with 3%wP, the THR was reduced by 25% and the maximal heat release rate by 60% compared to the reference. These results demonstrate the good flame retardant properties of reactive oligomers in epoxy matrix.


chain transfer reaction, phosphorus oligomer, reactive flame retardant, epoxy network
Access the publication