Study On Properties Of Filled Flame Retardants Unsaturated Polyester Resin

In this work Aluminum Trihydrate (ATH) and two kinds of phosphorus-containing polymers (Ammonium Polyphosphate (APP) and DEEP (Diethyl Ethanephosphonate), were used as filled flame retardants in unsaturated resin (UP). The reactivity, rheo-performance, flame retardant performance, thermal performance and mechanical performance of filled flame retardants unsaturated resins was investigated by Peak-Pro test, viscosity, LOI, UL-94, Smoke Density, HDT, Tg and mechanical tests. Study on combinations of additive flame retardants (ATH/APP, ATH/DEEP) which revealed different synergistic effect was carried out. The main studies and results are as follows:a) Rheological property of the resins filled with different amount of flame retardants was studied. Viscosity of the mixed system rapidly increased with the amount of FR additives increasing. High viscosity would cause great trouble to the resin casting and molding process. In this work, viscosity was reduced by styrene dilution and adding BYK additives, but the effect didn’t turn out well.b) Gel time and peak temperature of the mixed system was tested with the Peak-Pro method. As the loading amount of FR additives increased the gel time increased and peak temperature decreased. Gel time is a major consideration to determine the processing parameters, and it was adjusted by changing the amount of curing agent and accelerating agent.c) To study the flame retardant property, LOI, UL-94and SD were tested, it was found that, all three FR properties (SD, UL94and LOI) improved with the increase of flame retardants loading amount, APP shows better FR effect than DEEP and much better than ATH. The compound flame retardants showed excellent flame retardant performance, mainly reflecting in top grade of UL94burning test, high LOI and low SDR. Samples with ATH/DEEP got higher LOI value and lower SDR than those with ATH/APP in the same ratio, because the synergistic effect of ATH/DEEP was much better than that of ATH/APP.d) Influence of FR additives on thermo-property (HDT and Tg) of the UP resin was investigated. The variation tendencies of the HDT and Tg curve were approximately the same. As the loading amount of ATH increased, HDT and Tg increased first, then decrease and then increase. Changes of HDT and Tg were not obvious while using ATH/APP. Compared to single ATH, the compound ATH/APP was more effective on the improvement of the material’s heat resistance.e) Tensile and flexure properties of samples with different formulations were tested by Instron Universal Tester. The results showed that, both tensile strength and strain displayed a drop-down followed by an increase when ATH loading increased from20phr to110phr and APP loading increased from5phr to30phr. The tensile modulus was basically on the increase when increasing ATH or APP loading. However, DEEP affected the tensile modulus and strain in the opposite way compared with ATH and APP.It was shown that these studies can not only contribute to the formulation design of fire-retardant UP materials but also facilitate the process design of the fiber reinforced UP composites.