Morphology and Thermomechanical Properties in Epoxy Acrylate Interpenetrated Networks

Abstract

Interpenetrated Polymer Networks (IPNs) were produced from the simultaneous UV-photocuring of Bisphenol A propoxylate diacrylate (BPA-PDA) and 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (ECH) under a polychromatic source. Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM) were used to investigate the morphology of the samples, when dependence in thermal stability with the composition was evidenced from Thermogravimetric Analysis (TGA). The aptitude to create a wide range of thermomechanical properties was investigated towards Differential Scanning Calorimetry (DSC), Dynamic mechanical Analysis (DMA) and tensile tests. Post-curing contributes to increase the glass transition and the strain at break of the materials, and is also responsible to higher resistance to thermal degradation. Results show promising possibilities for the future development of graded materials with property control at different scales

A structural interpretation of the two components governing the kinetic fragility from the example of interpenetrated polymer networks

“…For each composition, the degree of swelling and the gel percentage were measured at ambient temperature after immersion in acetone following the same procedure as Yang et al The elastic modulus was determined at ambient temperature, about 298 K, from tensile tests (the curves are shown in Butterfield et al). The values of these parameters are given in Table , with the uncertainties calculated from repeatability.…”

“…In this work, a series of acrylate/epoxy IPNs with very different crosslinking densities and structural rigidities were considered (see SI.1, Supporting Information), which lead to a considerable variation of physical properties that generated a large domain of different molecular dynamics. More details on the IPNs investigated in this work can be found in a work previously published by Butterfield et al Cooperativity was investigated through Donth's approach based on modulated temperature differential scanning calorimetry (MT‐DSC) and fragility was determined from dynamic mechanical analysis (DMA).…”

Controlling properties of acrylate/epoxy interpenetrating polymer networks by premature termination of radical polymerization of acrylate

“…Figure shows the heat flow signals, which have been shifted and scaled to magnify the glass transition signatures (T g ). Pure acrylate (Tg = −30°C) and pure epoxy (Tg = 135°C) are included as references . In general, the FSC signals are not well defined, but show a gradual appearance of the acrylate Tg as the exposure time is increased.…”

“…Elastic modulus against acrylate content of the (a) sequential acrylate/epoxy IPNs, and (b) previously constructed simultaneous IPNs from the same systems []. [Color figure can be viewed at wileyonlinelibrary.com]…”

“…For comparison, Fig. b shows the modulus of simultaneous IPNs manufactured under a polychromatic lamp . As can be seen, the trends were similar, but the values of the sequentially made IPNs are smaller.…”