Thermal and surface characteristics of some β-cyclodextrin-based side-chain azo amphiphilic polyurethanes

New amphiphilic azo aromatic beta-cyclodextrin poly(ether urethanes) with different soft segment lengths have been synthesized and characterized. The thermal stability and kinetic parameters of the synthesized polyurethanes by using thermogravimetry (TG) and derivative thermogravimetry (DTG) under dynamic conditions of temperature, were evaluated. The non-isothermal kinetic parameters of the thermal degradation (activation energy, order of reaction, pre-exponential factor) were discussed in terms of the integral methods: Coats-Redfern, Flynn-Wall, van Krevelen and Urbanovici-Segal. The Reich-Levi method was also employed in evaluation of variation of the kinetic parameters with conversion. Surface parameters were evaluated based on contact angle determinations. Surface-free energy values and the polar and dispersive components were obtained by applying the Owens-Wendt-Rabel and the Kaelbe methods. (C) 2013 Elsevier Ltd. All rights reserved.