Preparation and properties of Waterborne polyurethane/nanosilica composites: A diol as extender with triethoxysilane group

• Published in: Journal of applied polymer science 2014-08, Vol.131 (15), p.np-n/a
• Main Authors: Wang, Gang, Ma, Guozhang, Hou, Caiying, Guan, Taotao, Ling, Lixia, Wang, Baojun
• Format: Article
• Language: English
• Subjects: Applied sciences; Chains; Composites; Contact angle; Diols; Elongation; Exact sciences and technology; Forms of application and semi-finished materials; Materials science; nanoparticles; Nanostructure; nanowires and nanocrystals; Polymer industry, paints, wood; Polymer matrix composites; Polymers; Polyurethane resins; polyurethanes; Reduction; Technology of polymers
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.40526

ABSTRACT Waterborne polyurethane (WPU) was prepared from toluene diisocyanate, polypropylene glycol, 2,2‐bis(hydroxymethyl)propionic acid and a diol containing triethoxysilane group as the chain extender which was synthesized via Michael addition between 3‐triethoxysilylpropylamine and 2‐hydroxyethylacrylate. Different amounts of nanosilica were incorporated into the WPU to prepare WPU/nanosilica composites. The results showed that the particle size of the emulsions increased and their viscosity decreased first and then increased with increasing the amount of nanosilica. Incorporation of nanosilica into WPU enhanced the water contact angle and thermal stability of the composites films, meanwhile, their tensile strength and hardness increased first and then decreased. However, increasing the amount of nanosilica resulted in reduction in the elongation at break of the films. It suggested that nanosilca was anchored into the side chain of WPU due to the condensation process between the triethoxysilane group in the side chain of WPU molecular and the silanols group on the surface of nanosilica. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40526.