Method to optimize fabricating process and FR properties of fiber reinforced unsaturated polyester composites

The influence of Aluminum Trihydrate (ATH) and Ammonium Polyphosphate (APP) on the LOI (Limited Oxygen Index) performance, UL-94 performance and smoke density of unsaturated polyester (UP) resin was investigated. It was found that all three FR properties improved with the increase of ATH loading till 110 phr. However, the influence of APP became not obvious? when the loading amount of it was more than 20 phr. More than 20 phr of APP had no further contribution to the FR properties of UP resin. The influence of ATH and APP loading on the physical properties of liquid unsaturated polyester resin was also studied so as to know the process-ability of unsaturated polyesters with different loading of ATH or APP. It was found that, the more ATH or APP, the more viscous, the longer the gel time and curing time and the lower the peak exotherm. For the cured resins both flexural strength and modulus displayed an increase followed by a drop down when ATH loading increased from 20 phr to 110 phr. However, the flextural strain showed a drop-down followed by an increase when increasing ATH loading. Flexural strength and strain decreased with increase of APP loading from 5 phr to 30 phr. Flexural modulus varied oppositely. 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. (C) 2013 International Association for Lire Safety Science. Published by Elsevier Ltd. Open access under CC BY-NC-ND license.