Brittle-ductile transition in the PETG/PC blends by adding PTW elastomer

In this paper, an elastomer containing epoxy groups, ethylene-butylacrylate-glycidylmethacrylate (PTW), was used as toughening modifier for the poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG)/poly-carbonate (PC) blends. A remarkable improvement of toughness was achieved by addition of only 5 wt% PTW. In particular, an obvious brittle-ductile (B-D) transition in impact toughness was found when the PTW content increased from 3 to 5 wt%. The toughening mechanism and observed B-D transition have been explored in detail, combining with electronic microscopy observation, melt rheological investigation and dynamic mechanical analysis (DMA). It is suggested that the B-D transition can be attributed to a better interfacial adhesion between different phases, and importantly, to a continuum percolation dispersed-phases network formed at appropriate PTW content, in which PC particles are connected with each other by PTW phase. Our present study offers new, profound insight on the toughening mechanism for the elastomer modified amorphous/amorphous plastic blends. Copyright (C) 2009 John Wiley & Sons, Ltd.