Modification of epoxy resin: a comparison of different types of elastomer

Composites were prepared using epoxy resin (ER), carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) and hydroxyl-terminated polybutadiene (HTPB), in different proportions. A chemical link between the HTPB and the epoxy resin was promoted employing tolylene diisocyanate (TDI). The reactions between elastomers and epoxy resin were followed by FTIR. The mechanical properties of the composites were evaluated and the microstructure was investigated through scanning electronic microscopy (SEM). The results showed that the impact resistance of CTBN-modified ER was superior to that of the pure epoxy resin. For the composites with HTPB, the impact resistance increased with elastomer concentration up to three parts per hundred parts of resin (phr). Higher concentrations of HTPB resulted in larger particles and gave lower impact values. (c) 2004 Elsevier Ltd. All rights reserved.