Polymer Engineering and Science, Vol.51, No.8, 1650-1661, 2011
Crystallization Studies on a Clay Nanocomposite Prepared From a Degradable Poly(ester amide) Constituted by Glycolic Acid and 6-Aminohexanoic Acid
An intercalated nanocomposite was prepared from an organomodified clay (Cloisite 25A) and a new biodegradable poly(ester amide) characterized by an alternating arrangement of glycolic acid and 6-aminohexanoic acid units by the melt-mixing technique. The influence of the final silicate layer morphology on hot and cold crystallization behavior was investigated by optical microscopy, differential scanning calorimetry, and synchrotron radiation. Primary nucleation increased significantly with the incorporation of nanoparticles, in contrast with the decrease previously observed when exfoliated structures were obtained. The secondary nucleation constant was higher for the nanocomposite sample, indicating that the growth mechanism was hampered by the presence of clay particles. However, the increase in primary nucleation had a greater effect, resulting in a faster overall crystallization rate for the nanocomposite. The addition of clay particles slightly reduced the degree of crystallinity attained after the hot and cold crystallization processes and favored a lamellar insertion mechanism. POLYM. ENG. SCI., 51: 1650-1661, 2011. (C) 2011 Society of Plastics Engineers