Morphologies and mechanical properties of polyethersulfone modified epoxy blends through multifunctional epoxy composition

Abstract

Thermoplastic polyethersulfone (PES) modified multifunctional tetraglycidyl-4,4 0 -diaminodiphenylmethane (TGDDM) and triglycidyl para-aminophenol (TGAP) epoxy prepolymers cured with 4,4 0 -diaminodiphenylsulfone (44DDS) were prepared using a continuous reactor method and their reaction-induced phase separated morphologies and mechanical properties were measured and correlated with chemical compositions. 1 H nuclear magnetic resonance ( 1 H NMR) and near-infrared spectroscopy (NIR) were used to quantify the chemical network formation. Atomic force microscopy (AFM) with nanomechanical mapping was employed to resolve the nanoscale phase-separated morphologies. The extent of phase separation in cured networks and resultant domain sizes were determined to be controllable depending upon the multifunctional epoxy compositions. The results obtained from mechanical studies further indicated that tensile modulus was not largely affected by multifunctional epoxy compositions while fracture toughness increased with increase of TGAP content.

Thermoset modified with polyethersulfone: Characterization and control of the morphology

“…It is important to note that the end‐group of the PES5003P can react with epoxy as studied by Cheng et al [31] and mentioned by Rosetti [13]. Thus an epoxy‐PES block copolymer is formed which is more soluble with epoxy than the PES.…”

“…Fernandez et al [35] did not see phase separation on TGDDM/DDM/PES system by SEM but DMA showed a small shoulder on the α‐relaxation peak of the TS which confirmed that phase separation had occurred. Cheng et al studied TGDDM/TGAP/44′DDS/15 wt% PES with OH end‐group through different formulations (along different quantities of each monomer) [31]. Besides no phase separation was seen on SEM, they distinguished nanophases around 50 nm by Atomic Force Microscopy.…”

Facile strategy and mechanism of greatly toughening epoxy resin using polyethersulfone through controlling phase separation with microwave‐assisted thermal curing technique

“…Although the two systems have similar toughening mechanism including energy consuming as well as preventing crack growth by particle bridging, crack deflection, and crack termination [Figure (a,b)], dimensions of thermoplastic phase will also play an effect on toughening. Specifically, the size of PES phase in m‐PES8/EP is about two times of that in t‐PES8/EP, so m‐PES8/EP has a bigger toughening effect than t‐PES8/EP (Figure ) because island with larger size tends to have a bigger toughening effect …”

Significant enhancement of fracture toughness and mechanical properties of epoxy resin using CTBN‐grafted epoxidized linseed oil

“…Polymeric matrices used for composite preparation can be classified into two types: thermoplastic and thermoset. Among these, epoxy resin (EP) has become one of the most widely used matrices for fabrication of fiber‐reinforced polymer‐based composites because of its processability, good mechanical performance, chemical resistance, and compatibility with most fibers . However, cured EP has a high sensitivity to external forces, due to its high crosslinking density .…”