Unsaturated Polyester Resin/Aluminum Tri-hydroxide Added with Short Glass Fiber for Battery Box

A battery box made of polymer material must consider mechanical strengthand flame retardancy. One solution to increase the flame retardancy of polymers is toadd a flame retardant filler. However, sometimes adding a flame retardant filler cancause degradation of mechanical strength compared to neat polymers. The combinationof more than one type of filler or hybrid fillers can produce the optimal combination offlame retardancy and mechanical strength. An experimental study was carried out tocharacterize several composite polymer samples of unsaturated polyester (UP) resincombined with fillers of aluminum tri-hydroxide (ATH) to increase flame retardancyand short glass fiber (G) to improve mechanical strength. The DSC results show thatthe maximum endothermic of all samples occurred at a temperature of around 70 ºC.The TGA results prove that ATH and G can maintain the thermal stability of UP so thatthe composite samples were degraded at higher temperatures by reducing the rate ofweight degradation due to a temperature of around 0.1%/ºC. The burning test alsoshows that samples with ATH and G have a lower burning rate value than neat UP. Formechanical characterization, the tensile strength of the samples with ATH and G waslower than that of neat UP. However, UP/ATH/G2 showed an optimal compositioncompared to other filler compositions with a tensile strength of 41.5 MPa. This samplealso produces an optimal bending strength of 68.9 MPa and even higher than neat UP.These results were confirmed by SEM observations, in which filler G was exfoliated inthe UP. The broken G particles on the fracture surface observation prove the goodinterlock bonding between UP and G, which contributes to increasing the mechanicalstrength of the UP composite.