Chemorheology of thermoplastic polyurethane and thermoplastic polyurethane/carbon nanotube composite systems. (2nd September 2016)

• Record Type: Journal Article
• Authors: Solouki Bonab, Vahab; Manas-Zloczower, Ica
• Is Part Of: Polymer. Volume 99(2016)
• Page Start: 513
• Page End: 520
• Publication Date: 2016-09-02
• Subjects: Chemorheology -- Thermoplastic polyurethane -- Thermoplastic polyurethane/carbon nanotube nanocomposite in-situ polymerization; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2016.07.043
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: In-situ polymerization of thermoplastic polyurethane (TPU) and carbon nanotubes (CNTs) is one of the best methods to obtain nanocomposites with well dispersed nanofillers and superior properties. The effect of nanofillers on reaction is an important factor during in-situ nanocomposite preparation. TPU/CNT nanocomposites were prepared via a sustainable in-situ polymerization of Polycaprolactonediol and 1, 4- Phenyldiisocyanate (PPDI) in the presence of multiwall carbon nanotubes. Chemorheological studies conducted at different temperatures indicated that by increasing the temperature, in addition to linear polymerization, branching and crosslinking reactions contribute to viscosity evolution. Empirical and semi-analytical chemoviscosity models were employed to clarify the difference between reaction kinetics of TPU formation in the presence of CNTs. A semi-analytical model developed here, gave more insight into the reaction as well as system structural evolution. Activation energy of viscosity evolution due to polymerization was found to decrease by addition of carbon nanotubes. This acceleration effect is correlated to higher heat conductivity of the nanocomposite as well as CNT effects on the structure evolution in the polymerizing system. Graphical abstract: Highlights: A semi-analytical model is developed to explain viscosity evolution during polyurethane polymerization. Semi-analytical model enables calculation of the activation energy of viscosity evolution due to polymerization. Incorporating CNTs into the reacting system accelerates the reaction. Branching contributes to viscosity enhancement in addition to linear polymerization at high temperature.