Mechanically strong waterborne poly(urethane‐urea) films and nanocomposite films

0535895 - ÚMCH 2022 RIV US eng J - Journal Article
Špírková, Milena - Pavličević, J. - Aguilar Costumbre, Yareni - Hodan, Jiří - Urbanová, Martina - Krejčíková, Sabina
Mechanically strong waterborne poly(urethane‐urea) films and nanocomposite films.
Journal of Applied Polymer Science. Roč. 138, č. 11 (2021), č. článku e50011. ISSN 0021-8995. E-ISSN 1097-4628
R&D Projects: GA ČR(CZ) GA18-03932S
Grant - others:AV ČR(CZ) UNESCO/IUPAC Postgraduate Course in Polymer Science
Institutional support: RVO:61389013
Keywords : coatings * composites * mechanical properties
OECD category: Polymer science
Impact factor: 3.057, year: 2021
Method of publishing: Limited access
https://onlinelibrary.wiley.com/doi/10.1002/app.50011

A series of transparent waterborne poly(urethane‐urea) (PUU) films and nanocomposite films were prepared using isocyanate excess (5–50 mol% excess relative to the hydroxyl groups) and omitting the common chain‐extension step in the acetone method of the preparation. The surplus isocyanate groups were converted into urea and eventually biuret linkages via the reaction with water during the last phase inversion step. Nanocomposites were prepared by the direct mixing of the PUU nanoparticles in water with aqueous nanosilica or montmorillonite powder followed by slow water evaporation. Variable urea/biuret content is responsible for substantially different tensile properties. The neat organic films show elongation‐at‐break values of 100%–1120%, tensile strength values of 0.07–22.1 MPa, and energy‐to‐break of 0.1–85 mJ × mm−3. All of the materials can be potentially used as soft‐to‐hard topcoats, depending on the specific demands. The most promising materials are films prepared at 30 and particularly 40 mol% isocyanate excess.
Permanent Link: http://hdl.handle.net/11104/0314362