DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
Cyanate Ester Resin Modified with Nano-particles for Inclusion in Continuous Fiber Reinforced Composites
Final technical rept. 15 Feb 2008-30 Nov 2010
IOWA STATE UNIV AMES
Pagination or Media Count:
The mismatch in coefficient of thermal expansion CTE between the polymer matrix and low CTE carbon fibers causes development of residual stresses in polymer matrix composites PMCs that can lead to micro cracking and failure. This report describes the development of hybrid polymer composites comprising of a unique low viscosity bisphenol E cyanate ester resin BECy resin reinforced with macro scale carbon fibers and negative CTE nanoparticles. Polymer nanocomposites were developed with negative CTE fillers such as multiwalled carbon nanotubes CNTs and zirconium tungstate ZrW2O8. The BECy ZrW2O8 nanocomposites were identified as the most promising candidates for development of hybrid composites and a silane surface treatment strategy was developed to improve the compatibility of the ZrW2O8 nanoparticles with the polymer matrix. The hybrid composites were prepared with 30 wt. unidirectional carbon fibers and various loadings of ZrW2O8 nanoparticles. Incorporation of 20 vol. ZrW2O8 nanoparticles was found to result in a 75 reduction in the normal and in plane CTE of 10 ply symmetric composites. Furthermore, the warpage in 2 ply unsymmetrical composites was found to decrease systematically with nanoparticle loading due to a reduction in the CTE mismatch between the matrix and fiber reinforcements.
APPROVED FOR PUBLIC RELEASE