Crystallization kinetics of polyurethane nanocomposites

Abstract

Nanocomposites of the segmented polyurethane (SPU) polymer containing different grades of Cloisite Ò nanoclay at 3 mass% loading have been prepared. The morphology of the prepared nanocomposites has been viewed through scanning electron microscope combined with energy dispersive X ray for the confirmation of the nanocomposite formation. Their non-isothermal crystallization kinetics have been investigated by applying modified Avrami and combined Avrami-Ozawa equations at four different cooling rates using a modulated differential scanning calorimeter. The crystallization parameters e.g., peak temperature (T p ), associated enthalpy (DH), etc., have been calculated. It has been observed that the addition of nanoclay into SPU accelerates the rate of nucleation and thereby, growth of crystallization in SPU. The Avrami exponent 'n' has shown two dimensional growth, while the rate constant 'Z c ' indicates an increase in the crystallization rate with increasing rate of cooling. The activation energy of the crystallization process has been calculated using Kissinger method. The glass transition temperature has also been estimated using thermomechanical analyzer, and the nanocomposites show superiority over the neat SPU.

Synthesis of Vegetable Oil‐Based Polyurethane: A Study on Curing Kinetics Behavior

“…Similar E a values were observed in all the B PU samples using the Ozawa model. Hence the E a for all polyurethane systems is very much similar to those reported earlier .…”

Shape Memory Materials from Rubbers

“…The shapememory performance of polyurethane in very low temperatures is significant for automobile industrial uses, such as low spin-out resistance, winter tires, and apparel constituents for usage in exceptionally icy environments, such as locations high above sea level [ 22 , 64 , 78 , 79 , 80 , 81 ].…”