Development of nanocomposite for rigid riser application: Diallyl bisphenol A modified Bismaleimide / epoxy interpenetrating network and its nanocomposite (NH2-MWCNT)

High performance composites have drawn substantial attention from the offshore industry for the development of rigid riser. This paper focuses on the development of a cost effective nanocomposite matrix system with a Tg of about 200 °C for potential use as a matrix in composite risers. An interpenetrating network (IPN) was developed by introducing Diallyl bisphenol A (DBA) modified Bismaleimide (BMI) into the Diglycidylether of Bisphenol A (DGEBA) epoxy matrix and it's nanocomposites were developed by introducing MWCNT (such as unfunctionalized and NH2-functionalized) into the BMI/DBA-Epoxy IPN. The effect of NH2-MWCNTs on the thermal and mechanical properties of NH2-MWCNTs/BMI/DBA/epoxy nanocomposite IPN were investigated and compared to un-functionalized MWCNTs/BMI/DBA/epoxy and BMI/DBA/epoxy IPN. Dynamic mechanical analysis shows significant increase in storage modulus as well as Tg (increased by 50 °C) with the addition of NH2-MWCNT in comparison to BMI/DBA/epoxy IPN. Mechanical studies indicated that the incorporation of NH2-MWCNT into BMI/DBA/epoxy resin not only improved the tensile (more than 2.5 times) and flexural strength (more than 2 times) but also significantly improved the impact strength of the composite (more than 3 times) in comparison to pure BMI/DBA/epoxy resin. It is noteworthy that the NH2-MWCNT/BMI/DBA/epoxy nanocomposite IPN resin exhibit improved thermal and mechanical properties, indicating that this novel toughened IPN resin system have great potential to be used as a matrix for advanced functional composites for rigid riser applications in offshore applications.