Toughening of epoxy resins is traditionally carried out by adding small proportions of a low Tg oligomer containing reactive end groups. These induce the precipitation of crosslinked rubbery particles during curing. In this study, an investigation was carried out to examine the possibility of using randomly functionalized low molecular weight polyethylene for the same purpose. In the first part of the work we examined the miscibility of binary and ternary blends of several low molecular weight polyethylenes, containing either hydroxyl or acid functional groups, with two types of epoxy resins and two anhydrides, respectively. Various chemical reactions were performed on some of the polyethylenes, as well as on a bisphenol epoxy resin, with the view to increase the miscibility between the components prior to the curing. From these experiments it was established that by modifying the polyethylene component with a monofunctional epoxy resin it is possible to substantially improve their miscibility with both types of difunctional epoxy resins, but to a lesser extent in the presence of anhydride hardeners.
Miscibilization of Low Molecular Weight Functionalized Polyethylenes in Epoxy Resins. I. Effects of Compositions and Modifications Chemistry
FRIGIONE, Mariaenrica;
1999-01-01
Abstract
Toughening of epoxy resins is traditionally carried out by adding small proportions of a low Tg oligomer containing reactive end groups. These induce the precipitation of crosslinked rubbery particles during curing. In this study, an investigation was carried out to examine the possibility of using randomly functionalized low molecular weight polyethylene for the same purpose. In the first part of the work we examined the miscibility of binary and ternary blends of several low molecular weight polyethylenes, containing either hydroxyl or acid functional groups, with two types of epoxy resins and two anhydrides, respectively. Various chemical reactions were performed on some of the polyethylenes, as well as on a bisphenol epoxy resin, with the view to increase the miscibility between the components prior to the curing. From these experiments it was established that by modifying the polyethylene component with a monofunctional epoxy resin it is possible to substantially improve their miscibility with both types of difunctional epoxy resins, but to a lesser extent in the presence of anhydride hardeners.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
