Synthesis and Properties of Organosilicon-GraftedCardanol Novolac Epoxy Resin as a Novel Biobased Reactive Diluentand Toughening Agent

摘要

The aim of this work is to develop a biobased functional reactive diluent for thermosetting epoxy resins suitable for high-performance applications. An advanced organosilicon-grafted cardanol novolac epoxy resin (SCNER) was synthesized from cardanol novolac epoxy resin and heptamethyltrisiloxane. After the chemical structure of SCNER was identified by Fourier transform infrared, ¹H NMR, and ¹³C NMR, it was used to modify the diglycidyl ether of the bisphenol A (DGEBA)/methylhexahydrophthalic anhydride system. The SCNER showed unique advantages, reducing the viscosity of DGEBA and improving the properties of the cured resin. With 10 wt % SCNER, the cured resin exhibited a higher tensile strength (78.84 MPa) and impact strength (32.36 kJ·m^–2). The single glass transition temperature (Tg) step proved the homogeneous phase structure of the cured resin. Inevitably, the Tg of the cured resin decreased for the addition of SCNER. The dynamic mechanical analysis results indicated that the storage modulus of the cured resin decreased with the increasing content of SCNER. The morphology showing the ductile fracture of the cured resinwas testified by scanning electron microscopy. The dilution and tougheningproperties of SCNER paves the way to a wide range of possible “eco-friendly”applications, especially in the fields of coatings, paintings, andadhesives.