The Effects of Some Phosphorus-Containing Fire Retardants on the Properties of Glass Fibre-Reinforced Composite Laminates Made from Blends of Unsaturated Polyester and Phenolic Resins

This study investigated the effects of phosphorus fire retardants (FRs) in matrices from co-cured blends an unsaturated polyester (UP) with inherently fire-retardant phenolic resoles (PH) on mechanical and flammability properties resultant glass fibre-reinforced composites. Three different UP have been used: (i) ethanol soluble (PH-S), (ii) epoxy-functionalised (PH-Ep), (iii) allyl-functionalised resin (PH-Al) two FRs: resorcinol bis (diphenyl phosphate) (RDP) 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). The flammabilities composites were evaluated using cone calorimetry UL-94 test. Cone calorimetric results showed reductions peak heat release rate (PHRR) total released (THR) as expected compared to those respective UP/PH composite laminates without FRs. tests that while all had HB rating, FR containing samples self-extinguished after removal flame. flexural, tensile impact tests. All FRs reduced properties, reduction was more severe UP/PH-S (least compatible blends) than UP/PH-Al (most Amongst composites, DOPO best retardancy little deterioration performance.