Evaluation of the Degree of Exfoliation in Poly(<i>ε</i>‐caprolactone)/Organoclay Nanocomposites Based on Viscoelastic Relaxation

Abstract

Abstract Poly( ε ‐caprolactone) nanocomposites, PCLOC25A and PCLOC30B, with organoclays (OCs) having nonpolar and polar organic modifiers, respectively, were prepared by the melt mixing method and additional heat treatment. WXRD analysis revealed that both nanocomposites were exfoliated, irrespective of the OC polarity. However, WXRD failed to show the degree of exfoliation of the nanocomposites, because the d 001 peaks disappeared. Thus, dynamic mechanical analysis (DMA) was carried out to compare the degree of exfoliation of the PCL nanocomposites. From DMA, PCLOC30B showed higher elasticity, storage moduli, viscosity, and activation energy than PCLOC25A, indicating that PCLOC30B had a more exfoliated structure than PCLOC25A. This is due to the polar interaction in PCLOC30B, as verified by the plots of a T versus temperature. Thus, it was confirmed that DMA provides an alternative approach to evaluating the degree of exfoliation of nanocomposites. magnified image