The use of wheat straw phenol condensation products as molded materials

In this study, wheat straw (Triticum aestivum L.) was successfully phenolated using hydrochloric acid (HCl) as a catalyst under atmospheric pressure in order to make novolak resin-type molded materials. The relationship between phenolation parameters (i.e., conversion ratio and the amount of reacted phenol) and some reaction factors was investigated. In addition, the flow properties and molecular weight of the phenolated straw as well as some static and dynamic mechanical properties of the phenolated straw-based molded materials were studied. It was found that the straw could be thermo-plasticized after phenolation and its molecular weight could be considerably reduced. Moreover, it was determined that the phenolated straw could be cured with hexamethylenetetramine (HMTA), and the mechanical properties of the resulting molded materials were comparable to those of commercial Novolak resin-based materials.