Initial Studies in the Characterisation of a Polymer Matrix for use in Composite Wind Turbine Blades

Hitachi Chemical Company Ltd. (HCCL) has developed a glass fibre reinforced polymer composite based on an anhydride-cured epoxy resin. Preliminary HCCL testing has suggested that it has improved interlaminar and mechanical properties compared to the amine-cured epoxy system which is currently used, making it an attractive alternative for use in wind turbine blades. In this work, extensive studies on the epoxy-anhydride system were conducted, allowing the determination of thermal properties, such as the glass transition temperature and modulus, along with cure kinetics. Processing parameters of rheological behaviour and in-situ resin shrinkage during cure were also studied. The apparent interlaminar shear strength was determined to be 62 MPa, verifying the improved interlaminar properties originally stated. The multifaceted nature of this research enabled the characterisation of a novel composite system, this will be pivotal in future research to develop an informed manufacturing process and has identified some mechanical properties which can be improved.