Influence of TiO2 and Fe2O3 fillers on the thermal properties of poly(methyl methacrylate) (PMMA)

doi:10.1016/j.matlet.2004.09.014

Materials Letters

Volume 59, Issue 1, January 2005, Pages 36-39

https://doi.org/10.1016/j.matlet.2004.09.014 Get rights and content

Abstract

The thermal properties of pure poly(methyl methacrylate) (PMMA) and PMMA filled with 5%, 10%, 15% and 20% of nanometric particles of titanium oxide (TiO₂) and ferric oxide (Fe₂O₃) were investigated under air atmosphere by DSC, TGA and LOI measurements on samples prepared by solvent casting method. In the presence of the filler, the thermal stability of the polymer appeared to be significantly improved. A linear relationship between LOI and glass transition temperature (T_g) suggests that the restriction of mobility of the polymer chains is directly linked to the increase of stability.

Introduction

The improvement of thermal and flammability properties of polymer materials is a major concern, particularly in the domains of transportation, building, civil and electrical engineering. Numerous and recent studies have shown the interest of the use of lamellar nanofillers (above all modified montmorillonites) as flame retardants [1], [2] or as components of flame retardants systems [2]. Moreover, the use of oxide particles in the submicronic or nanometric range as synergistic agents in addition to usual fire retardant additives seems to be very promising. Since a few years ago, we are involved in the search of strongly fire retarded poly(methyl methacrylate) (PMMA), and, at present, we have undertaken researches with such an approach. In a first step, we are investigating the influence of oxide fillers alone on the thermal properties of PMMA before to incorporate them as synergistic agents of phosphorous flame retardants. This paper presents the first results obtained with Fe₂O₃ and TiO₂ fillers.

Section snippets

Sample preparation

The poly(methyl methacrylate) was from Aldrich with a weight-average molecular weight of 350,000 g mol⁻¹ (based on GPC analysis) and obtained by free radical synthesis.

Commercial TiO₂ from Degussa (P-25 99.5%) with a mean particle size of 21 nm was used. The surface area was checked by the BET method and found equal to 48 m² g⁻¹. Submicron Fe₂O₃ particles were prepared according to the procedure described by Deb et al. [3]. The method is based on the precipitation of ferric oxide hydroxide

Conclusion

The thermal properties of PMMA filled with titanium oxide (TiO₂) and ferric oxide (Fe₂O₃) were investigated under air atmosphere by DSC, TGA and LOI measurements and compared to those of PMMA alone. From the results obtained, an improvement of the thermal stability was observed increasing with the amount of oxide. A direct influence of the restriction of mobility of the polymer chains on the thermal oxidative degradation mechanism is suggested to explain the observed phenomena.

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Citation Excerpt :
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Influence of TiO2 and Fe2O3 fillers on the thermal properties of poly(methyl methacrylate) (PMMA)

Abstract

Introduction

Section snippets

Sample preparation

Conclusion

Appl. Clay Sci.

Scr. Mater.

Polym. Degrad. Stab.

Polym. Degrad. Stab.

Polym. Degrad. Stab.

Influence of TiO₂ and Fe₂O₃ fillers on the thermal properties of poly(methyl methacrylate) (PMMA)