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Fire retardant polyurethane elastomers/aluminophosphorate nanocomposites for higher temperature application
|Magdalena Jurczyk-Kowalska , Joanna Ryszkowska , Krzysztof J. Kurzydlowski
Warsaw University of Technology, Faculty of Materials Science and Engineering (InMat), Wołoska 141, Warszawa 02-507, Poland
Nanocomposites offer new possibilities in the area of fire retardant polymer-based materials. Traditional flame retardant polymeric composites, containing aluminum trihydrate and magnesium hydroxide, require a high content of the filler. Volume fractions of more than 60 weight % are needed for sufficient flame resistance in the industrial applications. Compared with micro-composites, the corresponding nano-composites show significantly improved properties at the filler content of 2-10 wt. %.
Boehmites ([Al(O)(OH)]n) are composed of Al-O double layers interconnected by hydrogen bonds between the hydroxyl groups. The size of boehmite crystals used in commercial applications is below 100 nm. An important advantage of such boehmite nanoparticles is commercial availability and possibility to tailor their interfaces (either hydrophobic, hydrophilic, silane treated and organically modified), which is crucial for their dispersion in a polymeric matrix.
This work reports the results obtained in the study aiming at evaluation of the possibility to use of phosphate-modified boehmite particles in fabrication of polyurethane elastomers nanocomposites. Polyurethane elastomers/aluminphosporates composites were prepared via in-situ polymerization from poly(ethylene adipate), 4,4’diphenylmethane diisocyanate, glycol and glycerine and 0,5 wt. % of aluminophosphorates. Two ways of the filler dispersion were employed, by (a) ultrasonic and mechanical mixing and (b) by mechanical mixing alone.
Investigations of the composite nano-structure have been carried out using high-resolution microscopy. Thermally activated phase transformations were studied using differential scanning calorimetry. Thermal stability and thermal degradation were determined by thermogrvimetric analyses. The results are discussed in terms of the possible applications of developed nanocomposites.
AcknowledgmentsThe authors thanks the Prof. Z. Florjańczyk , dr A.Wolak and K.Łokaj a for supplying modified boehmite.
Presentation: Poster at E-MRS Fall Meeting 2009, Symposium I, by Magdalena Jurczyk-Kowalska
See On-line Journal of E-MRS Fall Meeting 2009
Submitted: 2009-05-19 12:20 Revised: 2009-08-02 16:59