Two‐component interpenetrating polymer networks (IPNs) from polyurethanes and epoxies. I. Studies on full IPN, pseudo‐IPN, and graft polymer alloys of polyurethanes and epoxies

Abstract

In this article we review the synthesis and morphology and the physical and mechanical properties of two‐component interpenetrating polymer networks (IPNs) from polyurethane and epoxy polymers; the corresponding pseudo‐IPNs and grafted IPNs are also discussed. A comparison was made of full IPNs, pseudo‐IPNs, grafted IPNs, and related homopolymers by examining their mechanical properties, mechanical spectra, and electron microscopy on an investigation of the effects of interpenetration or permanent entanglement in the IPN and related systems. This interpenetration has resulted in improved compatibility between the two polymer systems and has caused a decrease in the degree of phase separation. An observed shift in the dynamic glass transition temperatures (Tgs) of the two components which yielded a single IPN Tg further substantiates our results.

Composites of UHMWPE fiber reinforced PU/epoxy grafted interpenetrating polymer networks

“…The tensile and Izod impact strengths of the PU/DGEBA-g-IPNs increased upon increasing the PU content. This behavior is due to the covalent chemical bonding between the PU and DGEBA networks and, possibly, permanent interpenetration and entanglement between the PU and DGEBA networks [18]. As a result, the polyurethane was dispersed in the PU/DGEBA-g-IPN system on the molecular scale; the cross-linking density between PU and DGEBA and the dispersion of polyurethane in the PU/DGEBA-g-IPN systems clearly enhanced the tensile strength and Izod impact strength.…”

Photocured Simultaneous and Sequential PDMS/PMMA Interpenetrating Polymer Networks

“…Some authors have chosen to directly compare sequential and simultaneous IPNs by using the same polymers at similar concentrations to determine the impact of network architecture on various properties. − These studies generally compare optical properties, mechanical properties, and miscibility as reflected by the observation of single or multiple glass transition temperatures. In a previous publication, we demonstrated the ability to synthesize UV-cured semi-IPNs of PDMS and PMMA using a sequential route and UV-cured graft IPNs of PDMS and PMMA using a simultaneous reaction (Figure ).…”

Preparation and Properties of Toluene-Diisocyanate-Trimer-Modified Epoxy Resin

“…Thus, an interface is formed between PUP and the modified EP, giving poor compatibility. Meanwhile, in Figure 4c, uniform fibers and the typical flexible fracture surface can be seen, which means that a complete network was formed [39]. This may be the reason for the results shown in Figure 2 and Figure 3.…”