The effect of clay and mixing conditions to fire resistant and mechanical property of unsaturated polyester – glass fiber composites by a vacuum bagging method

Glass fiber reinforced polymer (GFRP) composites have a weakness in fire resistant property. The addition of clay can improve the fire resistant property of GFRP. However, a good mixing is needed to disperse the clay. This research aims to observe the effect of clay and mixing conditions on fire resistance and impact strength of GFRP/clay composites. Unsaturated polyester (UP), glass fiber and 3-Aminopropyltriethoxysilanewere used as a matrix, a reinforcement and a compatibilizer, respectively to build the composites. Unsaturated polyester-clay-silane were mixed using a magnetic stirrer with a variation of rotation speed and mixing duration. The composites were fabricated using a vacuum bagging method. The composition of clay was varied from 1, 2, and 3 wt%. The rotation speed and mixing time were varied at 100, 150, 200 rpm and 60, 90, and 120 minutes, respectively. UP-glass fiber was used as a comparison material. The results showed that composites with 1 wt% clay content was not burned with the burning rate value of 0 mm/min. There were no significant effects of variables on impact strength in between the boundaries that attributed to different mechanisms such as shear and diffusion that worked together to disperse the clay. The shear action should work at high speed rotation and short mixing time, while diffusion at low speed rotation and long mixing time.