Organoclay‐filled caprolactam‐blocked methylenediphenyl diisocyanate‐toughened epoxy interpenetrating network matrices

Abstract

Abstract An interpenetrating networks of varying weight percentages (5, 10, and 15%) of caprolactam‐blocked methylenediphenyl diisocyanate(CMDI)‐toughened epoxy matrices were developed and characterized. The toughened epoxy system was further modified with 1, 3, and 5% (by wt) of organophilic montmorillonite (MMT) clay. Organoclay‐filled hybrid CMDI‐epoxy matrices, developed in the form of castings, were characterized for their thermomechanical properties. The data obtained from differential scanning calorimetry and dynamic mechanical analysis showed that there was a significant loss in the values of glass transition temperatures ( T g ) of organoclay‐filled hybrid epoxy systems when compared with that of neat epoxy resin, whereas increasing trend in thermal stability was observed. The values obtained from mechanical studies indicated that the CMDI‐toughened epoxy and organoclay‐filled CMDI‐epoxy systems were improved the mechanical properties according to its percentage concentration. From X‐ray diffraction analysis, it was observed that the presence of d 001 reflections of the organophilic MMT clay in the CMDI‐toughened epoxy systems indicated the development of intercalated clay structure which in turn confirmed the formation of intercalated nanocomposites. Homogeneous surface morphologies of CMDI‐toughened epoxy and organoclay‐filled CMDI‐toughened epoxy systems were ascertained from scanning electron microscope. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers