The impact of water released from boehmite nanoparticles during curing in epoxy‐based nanocomposites

Abstract

The enhancing effect on mechanical properties of boehmite (γ‐AlOOH) nanoparticles (BNP) in epoxy‐based nanocomposites on the macroscopic scale encouraged recent research to investigate the micro‐ and nanoscopic properties. Several studies presented different aspects relatable to an alteration of the epoxy polymer network formation by the BNP with need for further experiments to identify the mode of action. With FTIR‐spectroscopic methods this study identifies interactions of the BNP with the epoxy polymer matrix during the curing process as well as in the cured nanocomposite. The data reveals that not the BNP themselves, but the water released from them strongly influences the curing process by hydrolysis of the anhydride hardener or protonation of the amine accelerator. The changes of the curing processes are discussed in detail. The changes of the curing processes enable new explanation for the changed material properties by BNP discussed in recent research like a lowered glass transition temperature region (Tg) and an interphase formation.

Electrospun Nanocomposite Fibers of Polycarbonate- and Taurine-Modified Boehmite Nanoparticles: What Can Be Learned from Structural and Thermal Investigations?

“…However, the residue found from TGA measurements depicts a nonlinear dependence and exhibits lower BNP amounts than formulated. However, as the BNP was not dried, some of the initial mass might be attributed to water contained in the nanoparticles, which can be, in principle, lost at high temperatures during the TGA measurements . Furthermore, some BNP might be lost during the electrospinning process from the spinning solution, where also BNP might be deposited outside the rotating collector.…”

“…However, as the BNP was not dried, some of the initial mass might be attributed to water contained in the nanoparticles, which can be, in principle, lost at high temperatures during the TGA measurements. 37 Furthermore, some BNP might be lost during the electrospinning process from the spinning solution, where also BNP might be deposited outside the rotating collector. Therefore, all estimated quantities are plotted versus the formulated BNP concentration.…”