The marriage between hardness and flexibility of epoxy
resins (improved toughness) is a desired feature, which
broads their application in various industrial fields,
especially for high impact resistance purposes.
Accordingly, this work aims to improve toughness
properties of epoxy resin (Epon-828)/Ancamine (curing
agent) system using amino-terminated hyperbranched
poly(ester-amine) [Poly(PEODA-NPA)] (HP) as toughening
and/or co-curing agent, in presence of organomodified
Montmorillonite clay (OMMT) as a reinforcing
filler. HP was synthesized via Michael addition reaction
of poly(ethylene glycol) diacrylate (PEODA) to Nmethyl-
1,3-propanediamine (NPA). Chemical structure
and molecular weight of HP were elucidated using
infrared (FTIR) spectroscopy and gel permeation chromatography
(GPC) techniques, respectively. Epoxy/
OMMT nanocomposites toughened with HP (at different
concentrations) showed remarkable improvement
in their toughness without any adverse effect on the
other physico-mechanical properties. The optimum
concentration of HP and OMMT was found to be 20 wt
% and 1–3 wt% of the epoxy resin, respectively. The
extent of exfoliation and dispersion of OMMT platelets
within the epoxy cured films was assessed by X-ray
diffraction (XRD) and transmission electron microscopy
(TEM) measurements. In addition, thermal gravimetric
analyses (TGA-DTA) of epoxy/OMMT nanocomposites
toughened with HP showed a slight increase in their
decomposition temperature, particularly at low OMMT
loading.
د.مشيره سامى عبد العزيز يوسف | Dr.Moshera Samy Abdelaziz Youssef | 2249