engleski

Silane pre-treatment of calcium carbonate nanofillers for PU composites

In this work we have investigated the effects of CaCO3 nanofiller pre-treatment by using two functional trialkoxy silane coupling agents. The aim was to improve the filler distribution and interactions with PU matrix of high plasticity. The main problem in the achievement of the improved and/or new properties in nanocomposites is uniform distribution of nanofillers without agglomerates, which could assure the strong interactions with matrix. Silane coating can be reactive and act as coupling agents between filler and polymer, reduce the agglomeration and improve the compatibility and dispersion. The chemical interactions between the various silane coupling agent and CaCO3 filler were studied by Fourier transform infrared spectroscopy. In this work the polyurethane composites were prepared by mixing procedure. Mechanical and thermal properties of PU composites have been determined. The CaCO3 filler surface pre-treatment by silane changed the filler surface energy and influence on the interactions with matrix in PU composites. The effect of CaCO3 addition into PU matrix was a composite reinforcement. DMTA analysis of PU composites showed the significant decrease of tand and increase the modulus E', respectively. The results were interpreted as a consequence of a constrained matrix structure due to a direct influence of nanofiller particles on the molecular movements of polymer chains.

PU composites; CaCO3 nanofiller; silane pretreatment; FTIR; mechanical properties; failure

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