0462571 - ÚMCH 2017 RIV NL eng J - Journal Article
Serkis, Magdalena - Špírková, Milena - Hodan, Jiří - Kredatusová, Jana
Nanocomposites made from thermoplastic waterborne polyurethane and colloidal silica. The influence of nanosilica type and amount on the functional properties.
Progress in Organic Coatings. Roč. 101, December (2016), s. 342-349. ISSN 0300-9440. E-ISSN 1873-331X
R&D Projects: GA ČR(CZ) GA13-06700S
Institutional support: RVO:61389013
Keywords : polymer-matrix composites (PMCs) * mechanical properties * microstructures
Subject RIV: CD - Macromolecular Chemistry
Impact factor: 2.858, year: 2016 ; AIS: 0.51, rok: 2016
DOI: https://doi.org/10.1016/j.porgcoat.2016.07.021

Novel waterborne polyurethane/silica nanocomposites were prepared via blending of two aqueous dispersions. Polyurethane water dispersion (PUD) was synthesized from polycarbonate diol (PC), 1,6-diisocyanatohexane (HDI) and butane-1,4-diol (BD) in order to provide solely linear character of PU chain. Two types of commercial colloidal silica, Ludox AS and Ludox TMA, differing in the size, shape and type of counter ions were used. The nanocomposites were made from negatively charged PUD and aqueous nanofiller sol at concentrations 5, 32 and 50 wt% of nanosilica. The films were obtained after slow drying of the water mixtures and characterized by AFM, SEM, tensile testing, DMTA, TG and water uptake measurements. It was found that all films are thermoplastics materials, reinforced by hydrogen bonds between silica particles and the polymer matrix, soluble in organic solvents and possible to re-production of PUD. Ludox AS was smaller than TMA and revealed better improvement of PUD-based films due to higher physical cross-linking density. It was observed that film containing 32 wt% of silica Ludox AS showed ten-times increasing Young’s modulus with slight improvement of elongation at break and two-times higher melting temperature in comparison to the neat PU matrix. Moreover sample with 5 wt% of AS nanofiller loading revealed excellent water resistance (swelling 0.8%). The obtained PU/silica nanocomposites have promising applications in recyclable environment-friendly waterborne coatings.
Permanent Link: http://hdl.handle.net/11104/0262571