Non-isothermal crystallization kinetics in melt-drawn PCL/PLA microfibrillar composites

0468287 - ÚMCH 2017 RIV US eng C - Conference Paper (international conference)
Kratochvíl, Jaroslav - Kelnar, Ivan
Non-isothermal crystallization kinetics in melt-drawn PCL/PLA microfibrillar composites.
AIP Conference Proceedings 1736. Melville: American Institute of Physics, 2016 - (D’Amore, A.; Acierno, D.; Grassia, L.), s. 1-4, č. článku 020109. ISBN 978-0-7354-1390-0. ISSN 0094-243X.
[International Conference on "Times of Polymers (TOP) & Composites" /8./. From Aerospace to Nanotechnology. Ischia (IT), 19.06.2016-23.06.2016]
R&D Projects: GA ČR(CZ) GA13-15255S
Institutional support: RVO:61389013
Keywords : polymer composites * non-isothermal crystallization * kinetics
Subject RIV: JI - Composite Materials

The non-isothermal crystallization kinetics of the system poly(epsilon-caprolactone)/poly(lactic acid)/clay C15 and related microfibrillar composites has been studied using a simple method based on mathematical treatment of the DSC cumulative crystallization curves in their inflection point. The method provides three kinetic parameters: temperature of start of crystallization, temperature of maximum crystallization rate, and numerical value of the maximum crystallization rate. In the range of cooling rates 5 – 20 degrees C/min, the temperatures of crystallization start and of maximum crystallization rate are determined with standard deviation of 0.3 and 0.4 degrees C, respectively. Average standard deviation of maximum crystallization rate is 1.0 K-1 corresponding to coefficient of variation 5.8 %. Repeatability is slightly better at lower cooling rates. The modified samples show intensive nucleation effect during the non-isothermal crystallization, as demonstrated by their values of temperatures of crystallization start and of maximum crystallization rate that are significantly higher than that of neat PCL. The highest maximum crystallization rate has been found for the blend PCL/PLA 80/20. The proposed method does not refer to any crystallization model and does not require exact determination of the starting point of crystallization. On the other hand, it does not provide any information about dimensionality of crystal growth. The method is particularly useful for characterizing a series of samples derived by modification of the neat polymer.
Permanent Link: http://hdl.handle.net/11104/0266305