Factors affecting the mechanical properties of mica‐filled polypropylenes

Abstract

Water‐ground Phlogopite mica (Kemira Siilinjarvi phlogopite) has been evaluated as a reinforcing filler in polypropylene. The major factors which influence the composite strength and modulus include the size, aspect ratio, and uniformity of the mica flakes. Aqueous delamination permits the production of very small flakes (less than 44 microns diameter) with aspect ratios near 50. Such small flakes impart greater tensile and modulus values to polypropylene than larger flakes and the former can also be reprocessed many times without any deterioration of properties. Surface treatment is necessary for adequate dispersion and coupling, particularly with the finely divided mica fillers. Other properties such as the heat‐distortion temperature, fracture toughness, and gas permeability are also influenced by the mean size and aspect ratio of the mica filler. Guidelines are presented to indicate the preferred characteristics of mica fillers for optimum performance.

Prediction of mechanical properties of composites of HDPE/HA/EAA

“…The results of E, σ B and ε B shown in Table 1 suggest that several parameters affect the mechanical properties of the composites: average particle size and particle size distribution of the filler (Busigin et al, 1983), adhesion of the compatibilizer or coupling agent to the filler (Newman and Meyer, 1980), the wettability of the filler (Inubushi et al, 1988) and the amount of compatibilizer or coupling agent used (Anderson and Farris, 1988). It is also important to note that for small particles, the interface between the filler and the binder plays a significant role (Inubushi et al, 1988;De Debnath and Khastgir, 1987;Jarvela and Jarvela, 1996).…”

Nucleation of Polypropylene Homo- and Copolymers

“…The main types of naturally occurring mica are phlogopite, muscovite and biotite, with muscovite being the preferred mineral due to its lack of color (Maine and Shepherd, 1974), whereas phologopite is normally dark brown with large aspect ratios (Busigin et al, 1983) and biotite has a dark-yellow or brown color (Trotignon et al, 1982). In addition to coloring effect, problems attributed to particle distribution and fracture have limited the application of mica, while other minerals such as kaolin or wollastonite have shown attractive industrial aspects.…”

Filled polymers: Mechanical properties and processability

“…The destruction of the matrix in a composite may be TaMe 17. Effect of the number of processing cycles on the properties of molded PP samples filled with mica particles [374] Mean At the same time a lower degradation of the polymer may be expected, according to preliminary data [378][379][380], in composites with P M F .…”