Abstract
Mica (i.e., muscovite and phlogopit) are platelet-shaped reinforcing fillers used for increasing heat deflection temperature and reducing warpage in polymers. Mineralogically the mica group consists of phyllosilicates all with monoclinic crystal structure and perfect basal cleavage. Micas are muscovite (typically white to gray color), phlogopite (brownish depending on iron concentration), biotite (dark brown to black), lepidolite (lithium-mica, white to gray), and others. Industrially in general and especially in polymers, the most commonly used are muscovite, phlogopite, and to some extent also biotite.
Main use is in polyamide for under the bonnet applications in automotive industry. They are truly versatile functional fillers. Whereas sheet and scrap mica minerals are used for larger thermal and electrical insulating shields, ground mica minerals (mostly muscovite) are used as fillers in lacquers, exterior and interior paints, plasterboards, joint compounds, adhesives, and sealants as well as in polymers. Most of the properties conveyed to the matrix are due to the crystal structure, chemical composition, fracture and cleavage behavior, as well as processing parameters used to produce the products. As functional fillers, mica mineral flours are making a crucial contribution to improve the properties of modern plastics.
In polypropylene muscovite mica is commonly used for reinforcing purposes due to the good equilibrium between modulus and IZOD strength as well as good HDT. Due to the brownish color, phlogopite mica is not that common in polypropylene although the reinforcing properties due to the good equilibrium between modulus and IZOD strength as well as a high HDT reveal the benefits for the compound even more than muscovite mica.
Muscovite and phlogopite mica are commonly used in polyamide 6 because of their equilibrated mechanical behavior but even more due to their ability to reduce isotropically the shrinkage of the compound and increase the HDT both resulting in extremely low warping materials. This is one of the prerequisites for using PA6 compounds as functional parts in environments being subjected to high temperature changes.
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References
Busigin C, Lahtinen R, Martinez GM, Thomas G, Woodhams RT (1984) Polypropylenes. T P-F Polym Eng Sci 24(3):169–174
Merlin Thomas AD (2013) A study on the influence of compatibilizer and mica filler on the properties of thermoplastic polyurethane/polyolefins blends. Chem Sci Trans 2(1):181–191
Nolte-Ernsting B (2007) Glimmer für temperaturbeständige Kunststoffe. Kunststoffe 9:237–240
Sreekanth MS (2009) Effect of concentration of mica on properties of polyester thermoplastic. J Min Mater Charact Eng 4(4):271–281
Thorsten Hilgers HM (2010) Properties made to measure. Kunstoffe Int 8:S.68–S.72
USGS (2012) U.S. geological survey minerals yearbook – 2011. US Department of the Interior, US Geological Survey, US Department of the Interior, US Geological Survey
Zilles JU (2006) High performance fillers conference 2006. Conference proceedings, Cologne
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Zilles, J.U. (2016). Micas. In: Palsule, S. (eds) Polymers and Polymeric Composites: A Reference Series. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-37179-0_14-2
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DOI: https://doi.org/10.1007/978-3-642-37179-0_14-2
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Publisher Name: Springer, Berlin, Heidelberg
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