Untitled

271

241

Three types of mineral fillers-talc, calcium carbonate (CaCO 3 ), and kaolin (10 -40 wt % filler loadings)-were compounded with polypropylene (PP) with a twin-screw extruder. The composites were injectionmolded, and the effects of the filler loading on the mechanical, flow, and thermal properties for the three different types of filled composites were investigated. The aim was to compare their properties and to deduce prospective filler combinations that would yield hybrid PP composites in following studies. The results showed that in most cases, the strength and stiffness of the talc-filled PP composites was significantly higher than those of the CaCO 3 -and kaolinfilled PP composites. However, CaCO 3 , being a nonreactive filler, increased the toughness of PP. The kaolin-filled PP composites also showed some improvement in terms of strength and stiffness, although the increases in these properties were not as significant as those of the talc-filled PP composites. The effects of interfacial interactions between the fillers and PP on the mechanical properties were also evaluated with semiempirical equations. The nucleating ability of all three fillers was studied with differential scanning calorimetry, and the strongest nucleating agent of the three was talc, followed by CaCO 3 and kaolin. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: [3315][3316][3317][3318][3319][3320][3321][3322][3323][3324][3325][3326] 2004

Section: Thermal Propertiesmentioning

confidence: 99%

Comparison of the mechanical properties and interfacial interactions between talc, kaolin, and calcium carbonate filled polypropylene composites

Leong

Bakar

Ishak

et al. 2004

271

241

“…7 Talc is a secondary mineral formed through the hydrothermal degradation of magnesium-rich metamorphic rocks. 8 For this reason, it is rarely found as a pure mineral, with chlorite groups {(Mg, Al, Fe) 12 [(Si,Al) 8 O 20 ](OH) 16 2 ] being the most common impurities. 9 The charge satisfaction of pure talc also leads to a different surface chemistry than many other clay minerals.…”

Section: Introductionmentioning

confidence: 99%

“…[10][11][12][13] PP has the highest stiffness and melting point and the best thermal resistance of all of the polyolefins. The modulus increase can be concomitant with an increase in the aspect ratio of platy minerals, but PP shows greater performance than, say, an uncoated kaolin, because of the greater compatibility of surface chemistries.…”

Section: Introductionmentioning

confidence: 99%

Effect of the talc filler content on the mechanical properties of polypropylene composites

Lapčík

Jindrová

Lapčı́ková

et al. 2008

This research examines the effect of a microsize/nanosize talc filler on the physicochemical and mechanical properties of filled polypropylene (108MF10 and 33MBTU from Saudi Basic Industries Corp. and HE125MO grade from Borealis) composite matrices. A range of mechanical properties were measured [tensile properties, bending properties, fracture toughness, notched impact strength (at the ambient temperature and À20 C), strain at break, and impact strength] along with microhardness testing and thermal stability testing from 40 to 600 C as measured by differential thermal analysis and thermogravimetric analysis. Increasing filler content lead to an increase in the mechanical strength of the composite material with a simultaneous decrease in the fracture toughness. The observed increase in tensile strength ranged from 15 to 25% (the maximum tensile strength at break was found to be 22 MPa). The increase in mechanical strength simultaneously led to a higher brittleness, which was reflected in a decrease in the mean impact strength from the initial 18 kJ/m 2 (for the virgin polypropylene sample) to 14 kJ/m 2 , that is, a 23% decrease. A similar dependency was also obtained for the samples conditioned at À20C (a decrease of 12.5%). With increasing degree of filling of the talc-polypropylene composite matrix, the thermooxidative stability increased; the highest magnitude was obtained for the 20 wt % sample (decomposition temperature ¼ 482 C, cf. 392 C for the virgin polymer).

“…This is because the ductility behavior is often related to the miscibility level. Thus, although negative deviations can be observed due to a decrease in the free volume as a result of mixing, 49,50 miscible and partially miscible blends usually present ductility synergistic 51,52 or neutral 40,53 values. Immiscible blends are expected to show negative deviations from the rule of mixtures 54 due to the lack of interfacial adhesion.…”

Section: As-molded Blendsmentioning

confidence: 99%

Compatibility in immiscible polysulfone/poly(ethylene terephthalate) blends

Retolaza¹,

Eguiazábal²,

Nazábal³

2004

Self Cite

Polysulfone (PSU)/poly(ethylene terephthalate) (PET) blends were obtained by direct injection molding across the composition range. Their phase behavior, thermal properties, morphology, and mechanical properties were measured. The blends were composed of a pure PSU amorphous phase and either a pure PET phase in PSU-poor blends, or a PET-rich phase with some dissolved PSU in PSU-rich blends. The morphology of the dispersed phase was mostly spherical with some elongated particles in the PET-rich blends. A slight synergistic behavior was observed in the Young's modulus, mainly in the 90/10 blend, which is probably due to orientation effects. The presence of some broken particles indicated some interfacial adhesion. The ductility values were approximately linear with composition. This was generally the case in PSU-rich blends, and was attributed to the higher level of PSU in the PET-rich phase. Although embrittlement was seen in blends with 30% of the second component, the ductility of the two pure components did not significantly decrease after annealing due to the presence of low amounts (up to 10%) of another component of the blend.