Barna, Elisabeth. Synthesis and characterization of scratch resistant polyurethane clear coatings by incorporation of surface modified nanoparticles. 2012, PhD Thesis, University of Basel, Faculty of Science.
Official URL: http://edoc.unibas.ch/diss/DissB_10057
In this work the reinforcement of different kinds of nanoparticles in transparent polyurethane coating compositions was studied, particularly with regard to scratch resistance of the resulting nanocomposite. Nanoparticles synthesized by flame spray synthesis, microemulsion polymerization and conventional aerosol process were employed as well as commercially available silica organosols. Some of these nanoparticles were surface modified with organosilanes to improve the interaction with the polymer matrix and provide for a uniform dispersion in the coating system. Surface modification with functional organosilanes bearing amino-, mercapto- or glycidoxy groups allow for reactive integration of the nanoparticles in the polyurethane network and thus enhance the mechanical properties. Also tailor made mixed oxide nanoparticles with a refractive index matched to that of the polymer system were synthesized via flame spray synthesis.
Nanoparticles were characterized by means of Transmission electron microscopy (TEM). The quality of organosilane surface modification was controlled with the help of Solid State 29Si NMR and Thermogravimetric Analysis (TGA). The nanoparticles were incorporated in polyurethane coating formulations and films thereof applied on glass sheets. After curing at 180 °C the transparency of these films was determined using UV/vis spectroscopy. To check the particle dispersion within the coating layer ultramicrotomed cross-sections were investigated by TEM. The scratch behavior of the nanocomposite films was studied with the help of a Nano Scratch Tester (NST). Further investigations like Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Thermal Analysis (DMTA) was performed on selected samples.
|Advisors:||Meier, Wolfgang Peter|
|Committee Members:||Taubert, Andreas|
|Faculties and Departments:||05 Faculty of Science > Departement Chemie > Chemie > Makromolekulare Chemie (Meier)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||75 S.|
|Last Modified:||30 Jun 2016 10:50|
|Deposited On:||03 Oct 2012 14:34|
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