Dynamic relaxations in a bio-based polyamide with enhanced mechanical modulus

摘要

A new grade of bio-based polyamide (PA)-PA meta-xylylene diamine 10 (PA mXD 10)-was investigated. Its first interest is that it permits mild processing conditions at about 200 degrees C. The calorimetric study shows the existence of two cold crystallizations indicative of slow crystallization rate. The glass transition stabilizes at 55 degrees C. By combining calorimetry with dynamic mechanical analysis and dynamic dielectric spectroscopy, we found a perfect consistency between the set of data giving the molecular mobility. The localized relaxations follow Arrhenius equations while the viscoelastic transition follows a Vogel-Fulcher-Tammann law. The compilation of all the relaxation times determined by means of the different analyses highlights a good correlation. This result is perfectly explained by the polarity of the macromolecular chain. The dynamic mechanical behavior showed a storage modulus higher than for the corresponding aliphatic PA and nearly constant until room temperature. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46846.