Thermoplastic toughened layered silicate epoxy ternary nanocomposites—Preparation, morphology, and thermomechanical properties

Abstract

Epoxy-clay ternary nanocomposites were processed by melt blending of hydroxyl terminated poly (ether ether ketone) oligomer with pendant methyl groups (PEEKMOH) with diglycidyl ether of bisphenol A (DGEBA) epoxy resin along with organically modified montmorillonite (OMC-OH) followed by curing with 4,4 0 -diamino diphenyl sulfone. Small angle X-ray diffraction and transmission electron microscopy revealed an intercalated morphology. Tensile, flexural, storage, and loss moduli were increased whereas the tensile, flexural, and impact strength and glass transition temperature were decreased with increase in clay content for the PEEKMOH toughened epoxy system. Fracture toughness and percentage strain were increased by 66% and 45% respectively whereas the coefficient of the thermal expansion was decreased by 27% with the incorporation of 1 phr OMC-OH to the PEEKMOH toughened epoxy system compared with neat epoxy. The scanning electron microscope pictures of fracture and tensile failed surfaces revealed crack path deflection and ductile fracture with the incorporation of OMC-OH confirming the improvement in toughness. The domain size and the distance between the domains of thermoplastic phase were decreased with the addition of nanoclay into the epoxy matrix indicating the restriction of the growth mechanism by nucleation during phase separation.

Eggshell reinforced biocomposite—An advanced “green” alternative structural material

“…Similar results have been reported in CaSiO 3 /SSE nanocomposites . Also, a study of CaCO 3 /bioplast showed improved dimension stability because of stiffer and deformation resistant CaCO 3 NPs which tend to restrict the motion of chain segments of the polymer …”

“…Modified CaCO 3 with silane coupling agent (KH550) has been found to have led to improvement in strength and toughness in epoxy/fiber composite . Also, about 13.5%, 6.1%, 42.5%, and 106.3% improvements in strength, modulus, displacement, and total fracture work was respectively obtained by unmodified nano‐CaCO 3 . Furthermore, nanosized CaCO 3 /polylactide nanocomposites showed improvement in strain‐at‐break over a pure polylactide system whereas, a study on fracture toughness and deformation mechanism of polypropylene/CaCO 3 composites showed that the addition of 15 wt % CaCO 3 NPs led to increase in the fracture toughness by 180% .…”

“…Figure (b,c) also shows evidence of microvoids in the composites. These flaws serve as stress concentration points in the materials and immensely lead to compromises in mechanical properties and unexpected failures . This indicates that there is high potential for further improvement in mechanical properties if the flaws can be minimized.…”

Nanoclay reinforced thermoplastic toughened epoxy hybrid syntactic foam: Surface morphology, mechanical and thermo mechanical properties

“…In our earlier studies, we have observed significant improvement in fracture toughness, modulus and thermal stability and reduction in gas permeability and CTE for thermoplastic (PEEKMOH and PES) toughened epoxy clay ternary nanocomposites [28][29][30][31]. The present study deals with the preparation and evaluation of surface morphology, mechanical and thermo mechanical properties of PEEKMOH toughened epoxy hybrid syntactic foam containing glass microballoon as hollow filler and Cloisite 30B as nanofiller.…”

Preparation and characterization of polyimide/modified layered double hydroxide nanocomposites

“…The anions (A n − ) in the interlayers of the LDHs are exchangeable, and a variety of anions can be incorporated. Therefore, these anions have received attention as prominent hosts for hybrid materials 5…”