US EPA

2645547 

Journal Article 

Delamination toughness of fiber-reinforced composites containing a carbon nanotube/polyamide-12 epoxy thin film interlayer 

White, KL; Sue, HJue 

2012 

1 

Polymer
ISSN: 0032-3861 

53 

1 

37-42 

10.1016/j.polymer.2011.11.022 

WOS:000300073600003 

We present a simple, out-of-autoclave approach to improve the delamination toughness of fiberreinforced composites using epoxy interlayers containing 20 wt.% polyamide-12 (PA) particles and 1 wt.% multi-walled carbon nanotubes (MWCNTs). Composites were prepared by integrating partially cured thin films at the laminate mid-plane using vacuum-assisted resin transfer molding. The introduction of epoxy/PA interlayers increased fracture toughness due to the ductile deformation and crack bridging of PA particles within an interlaminar damage zone with uniform thickness of about 20 pm. Composites interlayered with epoxy/PA/MWCNT exhibited nearly 2.5 and 1.5 times higher fracture toughness than composites containing neat epoxy and epoxy/PA interlayers, respectively, without an observable increase in interlaminar thickness. The fracture surface was analyzed to identify failure modes responsible for the fracture toughness improvement. The MWCNTs are proposed to inhibit critical loading of defects by minimizing stress concentration within the interlaminar region, thereby enabling greater deformation of the PA particles during fracture. (C) 2011 Elsevier Ltd. All rights reserved. 

Carbon nanotubes; Composite materials; Multi-scale