Surface functionalized boehmite sheets filled epoxy composites with enhanced mechanical and thermal properties

Abstract

Boehmite (AlOOH) sheets were synthesized via a hydrothermal method and then successfully functionalized with a bi-functional coupling agent, γ-aminopropyl- triethoxysilane (APTES), through a facile neutral solvent method. Scanning electron microscope and transmission electron microscopy images showed a uniform morphology of AlOOH sheets. APTES was found to be covalently bound with AlOOH sheets. The linked APTES can be combined with an epoxy oligomer through a ring opening addition reaction. The modified AlOOH was used as reinforcing agent to reinforce the epoxy resin cured by 4,4-diaminodiphenylsulfone. The results of tensile and differential scanning calorimetric test revealed the tensile strength and glass transition temperature (Tg) firstly increase and then decrease with the increase of functionalized AlOOH sheets loading. When the loading of functionalized AlOOH sheets increased to 5 parts per hundred resin, the highest tensile strength and Tg were obtained. They are 100.8 MPa and 174.5 °C. Microscopic examinations revealed the presence of large plastic deformations at the micronscale in the formed composites in agreement with the observed strengthening effect of functionalized AlOOH sheets. Copyright © 2014 John Wiley & Sons, Ltd.