Study On The Flame Resistances Of The Reactive Phosphorus-containing Flame Retardant To Unsaturated Resin

The composite materials of fibers reinforced resin matrix are increasingly used in industrial applications. And unsaturated polyester resin(UPR) is the largest amount of resin varieties.With the development of composite materials, the requirements of the resin are increasingly strict. Many applications need to give the UPR flame retardant properties with environmental protection. Therefore, the non-halogen flame retardant UPR is the focus of current research.The reactive phosphorus-containing flame retardants have a stable flame retardant effect, environmentally-friendly, little effect on the process performance and the physical mechanical properties of the resin. Therefore, the reactive phosphorus-containing flame retardants have become a hot research in recent years.2-Hydroxyethyl methacrylate phosphate(HEMAP) were used as the reactive phosphorus-containing flame retardant and added to the 191 UPR and TH110 Vinyl ester resin to improve them flame retardant properties. Studied the effects of HEMAP on curing kinetics, flame retardant properties, water resistance, bending and tensile performances of these two structural types of UPR.The results are as follows:The flame retardant resins with HEMAP were heat cured by BPO initiator. And by studying the cuing process of the flame retardant resins, we know that the initial curing temperature and the peak temperature were moved to lower temperature in the 191 resin with HEMAP flame retardants system. The Ea activation energy of this system decreased with the increase of HEMAP content. But the characteristic temperature and the Ea were improved in the HEMAP/TH110 flame retardants system. However, the reaction order hadn't been changed much in the both systems. HEMAP hadn't change the curing reaction type of the flame retardant resins.After adding HEMAP, the flame retardancy of 191 resin and TH110 resin have been improved. After adding 17wt% of HEMAP, the limiting oxygen index value improve to 29 in the U-20 of 191 resin systems. In the TH110 resin, after adding 9.1wt% of HEMAP, the limiting oxygen index value improve to 35 in the V-10 system. With adding HEMAP, the thermal stability of flame retardant UPRs has decreased. In N2 atmospheres, the decomposition temperature of 10% mass loss and maximum weight loss both dropped with increase of HEMAP. But the char yield at 800?of the two ststems increased. From U-0 system to U-20 system, the char yield of 191 resins significantly increased from 4.7% to 16%. From V-0 system to V-20 system, the char yield of TH110 resins significantly increased from 3.8% to 31%. The results of cone calorimeter test showed that, the heat release rate and the total heat release of unsaturated resin systems had reduced after adding HEMAP. The heat release rate and the total heat release of U-15 system were reduced by 40% and 38% compared with the U-0 system. And the heat release rate and the total heat release of V-15 system were both reduced by 23% compared with the U-0 system.Since HEMAP added to the resins with copolymerization, the crosslink density of the resin system had increased. So the bending properties and the tensile strength of the flame retardant resins were both improved. In the 191 resin system, the bending strength increased from U-0's 77.3MPa to U-20's 87.7MPa, and the tensile strength increased from U-0's 47.8MPa to U-20's 54.4MPa.In the TH110 resin system, the bending strength increased from V-0's 110 MPa to V-20's 121 MPa, and the tensile strength increased from V-0's 41.8MPa to V-20's 62.8MPa.Because the HEMAP has strong polarity, after adding HEMAP to the UPRs, the number of hydrophilic groups-OH in the systems had increased. So the water absorption of the resins was increased and the water resistance of the resins was reduced.