Peculiarities of mechanical response of heavily filled polypropylene composites
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Temperature dependences of dynamic moduli of polypropylene filled with flame retardant Mg(OH)2 or with CaCO3 were investigated. The filler content varied from O to 50 vol% and both storage (G′) and loss (G″) shear moduli were measured from + 50 to + 300 °C at frequencies 1 and 90 Hz. The influence of the filler particle shape was dominant for the origin of the physical network. Chemical adhesion aid was superfluous in composites with subcritical particle size. Two step decrease of G′ and two peaks on G″ temperature dependences were observed above the critical filler concentration. The explanation of this phenomenon was based on the proposal that polypropylene immobilized on the filler surface creates a new continuous phase, while primary polypropylene exists only in separated domains. Destruction of the physical network was explained using results of thermoanalysis, providing the catalytic effect of Mg(OH)2 on the thermal oxidation of polypropylene in the interlayer above 240 °C.
KeywordsPolypropylene CaCO3 Flame Retardant Thermal Oxidation Filler Content
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- 2.P. S. Theocaris in “Proceedings of the European Workshop on NDE of Polymers and Polymer Matrix Composites”, Technomic, Lancaster-Basel, 1986.Google Scholar
- 3.J. S. Lipatov and V. F. Babich, Mekh. kompoz. mater. 1 (1987) 17.Google Scholar
- 7.B. Pukanszky and F. Tüdös, in “Proceedings of the IUPAC International Symposium on Polymers for Advanced Technologies”, edited by M. Lewin (Jerusalem, 1987) p. 792.Google Scholar
- 12.Idem., J. Mater. Sci. (submitted).Google Scholar
- 13.J. Jančář, J. Kolařík and M. Kummer in “Proceedings of the 2nd International Conference on Interface in Polymer Composites”, Cleveland, July, 1988, edited by H. Ishida (Elsevier, New York, 1988) p. 746.Google Scholar
- 15.P. Veselý et al., in “Proceedings of the 4th European Symposium on Thermal Analysis and Calorimetry”, Jena, East Germany, 1987.Google Scholar
- 18.R. Zahradník and R. Hobza, “Weak Interactions”, Vol. 1 (Academia, Prague, 1982) p. 121.Google Scholar
- 19.P. N. Hornsby and C. L. Watson, Plast. Rubber Proc. Appl. 6 (1986) 169.Google Scholar