Poly(ester‐amine) hyperbranched polymer as toughening and co‐curing agent for epoxy/clay nanocomposites

Abstract

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 organo‐modified Montmorillonite clay (OMMT) as a reinforcing filler. HP was synthesized via Michael addition reaction of poly(ethylene glycol) diacrylate (PEODA) to N‐methyl‐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. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

A New Epoxy-Based Layered Silicate Nanocomposite Using a Hyperbranched Polymer: Study of the Curing Reaction and Nanostructure Development

“…HBPs have attracted considerable attention as modifiers of epoxy resins, principally for the purposes of toughening [ 13 – 19 ], though their effects on the morphology [ 20 – 22 ] and on other properties, such as the cure kinetics [ 23 – 25 ] and the thermal expansion coefficient and microhardness, have also been investigated [ 26 ]. The study of HBPs in epoxy composites in general [ 27 ] and in nanocomposites in particular has been more limited, most studies being on polyurethane nanocomposites [ 28 – 35 ], although there have been some studies on HBPs in epoxy-based nanocomposites systems [ 36 – 38 ], in which the epoxy is usually DGEBA.…”

“…The supposed advantages of incorporating an HBP in the nanocomposite system are both to improve the dispersion of the clay in the epoxy resin matrix and also to increase the degree of exfoliation that takes place when the system is cured. In this respect, we review briefly the results reported in [ 36 – 38 ]. In the work of Becker et al .…”

“…Eissa et al . [ 38 ] fabricated DGEBA-based nanocomposites using an amino-terminated poly(ester-amine) HBP as a co-curing agent with a commercial amine hardener. For clay contents greater than 3 wt%, there are clear peaks in the small angle X-ray scattering (SAXS) scattering pattern, corresponding to about 3-nm d -spacing; for lower clay contents, the absence of peaks is not convincing, due to the substantial scatter, presumably as a consequence of insufficient exposure of the sample to the X-rays, while the TEM micrographs show clay agglomerations for the sample with5 wt% loading and are at too low a magnification to identify individual clay layers.…”

Thermal–oxidative degradation and accelerated aging behavior of polyamide 6/epoxy resin‐modified montmorillonite nanocomposites

“…The absence of solvents in proceeding the preparation is environmentally good and makes the process more suitable for industrialization . Heretofore, a wide variety of compounds have been intercalated in MMT by ion‐dipole interaction, such as amines, aniline salts, aldehydes, alcohols, imidazoles, block copolymers, epoxy resin, etc.…”

Using of Hyperbranched Poly(amidoamine) as Pretanning Agent for Leather

“…Several types of hyperbranched polymers were prepared such as polyphenylenes, polyethers, polyesters, polyamides, polycarbonates, poly(ether ketones), and polyurethanes [6][7][8][9][10][11][12]. Generally, hyperbranched polymers are readily feasible for different potential applications, such as toughening and cocuring agents, multifunctional initiators, rheology control compounds for surface modification, medical applications, nanofillers for polymer nanocomposites, nonlinear optics, nanoporous generators for low dielectric constant insulators, coatings, and drug delivery systems [13][14][15][16][17][18][19][20][21][22][23][24]. Therefore, hyperbranched polymers are of immense importance for industrial applications.…”