Structure and properties of a poly(amino ether) resin after reprocessing in the melt state

The effects of reprocessing by extrusion for up to five cycles, at both the usual (200°C) and an extreme (230°C) temperature, on the structure and mechanical properties of a poly(amino ether) (PAE) resin were studied. A slight darkening and viscosity increase was observed, mainly upon reprocessing at 230°C. The melt flow index and solubility analysis indicated that grafting and crosslinking reactions took place, respectively, after reprocessing at 200 and 230°C. The Young′s modulus and the yield stress of PAE increased slightly with successive extrusion cycles. This was attributed to the viscosity‐induced increase in orientation, and to a minor extent to the partially grafted/crosslinked nature of the samples. The decrease in the ductility was more noticeable in the samples reprocessed at 230°C, and was attributed to the reduced ability to elongate of partially grafted and partially crosslinked structures present after reprocessing, respectively, at 200 and 230°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1368–1373, 2006