Effect of filler addition

The purpose of this work was to study the effects of filler addition on the properties and microstructues of both Cj/SiC-BN composites and Cf/SiC-ZrC composites. 

It is observed from Table 4 that the effect of filler addition on tensile strength is far more than that on flexural strength. At 40% filler content, tensile strength is reduced by 40% while reduction in flexural strength is only 17.4%. 

Effect of fillers addition on the thermo-optical parameters of prepared composites was detailed in fig 3 and fig 4. Those two figures show the reflection coefficient for different wavelength ranges. They were used to calculate the solar absorption and the total emissivity of composites. 

Effect of Filler Addition on Flammability of Flame-Retardant PP Makoto Seino Masaya Kotaki ... 

EFFECT OF FILLER ADDITION ON FLAMMABILITY OF FLAME-RETARDANT PP.1877... 

The gluability of the lignin-epoxy resin adhesives was found to be improved by the addition of calcium carbonate (50% by weight) to the liquid resin. This must be attributed to the nature of the weak alkali in calcium carbonate as a cure accelerator, and to the reinforcement effect of fillers. Since wood surfaces are acidic, the addition of alkaline fillers effectively alters the pH of the glue line. 

The incorporation of carbon black into elastomeric systems is a process of significant commercial importance. However, the additional stiffness of the sample imparted by the reinforcement effect of fillers is not favourable in terms of the experimental conditions for high-resolution NMR spectroscopy. Electric conductivity of the carbon black may also interfere to some extent. Under these circumstances, filled formulations are not widely used for the study of elastomer vulcanisations where high resolution and signal-to-noise ratios are required to detect small amounts of vulcanisation products. 

In addition to jetness, plastics pigmented with carbon blacks typically exhibit color undertones. Undertone in black plastics appears as a distinct blue or brown-to-orange undertone, depending on the particle size of the carbon black used. In general, in full-shade, black molded applications, fine-particle-size carbon blacks impart a bluer tone. This behavior reverses itself in tints. Large-particle-size carbon blacks impart bluer undertone. Note that the effects of fillers, polymers, and dispersion can alter the typical behavior described above. Tint strength is the relative ability of the carbon black to darken a resin colored with chromatic pigments. 

Heat-resistant [218] soft foams were prepared from the blends of hdPE with E-P random copolymers. The azodicarbanamide acts as a thermal antioxidant and the crosslinking of the blend was increased by electron beam radiations and foamed at 225 °C with 2320% expansion. A blend of 35 wt.% PE-PP (8 92), 15 wt.% E-P block copolymers, and 50 wt.% EPDM showed accelerated weathering resitance [219] 1000 h probably due to crosslinking between constituents of the block copolymer, polyblend and EPDM. The effect of filler and thermodynamic compatibility on kaolin-filled PE-PP blend was studied by Lipatov and coworkers [220]. The thermodynamic interaction parameter (%) decreased and thermodynamic stability increased by filler addition, the degree of crystallinity decreased with increasing thermodynamic compatibility of the components due to sharp decrease in the phase separation rate during cooling. 

The effect of filler density on the density of filled product can be closely approximated by the additivity rule. If a more precise method of density estimation is required or filler/matrix mixtures are far Ifom being perfect, several corrections are necessaiy. System density becomes nonlinear close to the critical volume concentration (CVC). The critical volume concentration determines the amount of conductive filler which rapidly increases the conductivity of the composite. Figure 5.1 shows that at, or close to the critical volume concentration, density decreases. This density difference can be detected either after the CVC (polyethylene), before (polystyrene) or the two depressions are observed - one before and one after the CVC (polymethylmethacrylate) is reached. This density depression is due to filler-matrix interaction. 

Literature contains little data on the effect of fillers on hardness but what is available indicates that the addition of fillers increases hardness. 

The effect of filler on polymer melts is discussed in several papers. Figure 9.30 shows that the melt flow index decreases rapidly on calcium carbonate addition. The changes as concentration increases are much less pronounced. This study was conducted for a large particle sized (50-400 pm) grade of calcium carbonate. 

Figure 10.1 shows the effect of the addition of fillers to polypropylene on its crystallinity. This study was conducted under the same conditions for all specimens tested. There is a difference in the effect of CaCO-, and talc. Calcium carbonate lacks surface functional groups so it tends to have a very small influence on crystallinity and the crystallization behavior. Talc has interacting functional groups on its surface which cause the increase in crystallinity along with the concentration increase. 

Table 13.4 shows the effect of the presence and absence of 1% silica on the performance of various UV stabilizers in stabilized polypropylene. The performance of all stabilizers was substantially retarded in the presence of silica. The addition of silica without the presence of UV stabilizer improves UV stability of the polymer. The data shows that the effect of filler is not restricted to HALS but extends to a broad spectrum of UV stabilizers. 

Applications. Smoke evolution of commercial materials and the effect of various additives including fillers on smoke production rate. 

Figure 9.13 shows the effect of filler concentration on torque. The smallest increase was due to magnesium carbonate and the largest due to the presence of glass fibers. The mechanical properties of filled composites are substantially improved by additions of magnesium carbonate, wollastonite and glass fiber. The most important improvement is in creep resistance (Figures 6.68 and 8.69). 

The above description stresses either chemical reactions in these combinations or physical interactions between components. In reality there is still additional effect which may induce changes to structure and thus properties. It is a commonly known effect of fillers on the nucleation of polymers. It can be perceived that filler does not affect nucleation of both polymers with the same intensity. In addition, the availability of polymers at the interface with fillers depends on various parameters such as viscosity, acid/base interaction, etc. If these two are included in the number of combinations, there is a theoretical abundance of possible combinations and thus... 

Combination of several properties is becoming increasingly important in modem industry. One example may be taken from electronics, where in addition to mechanical properties and electric resistance, themial stability and conductivity are important requirements. It was estimated that the increase of temperature by 10°C reduces time to failure by the factor of two." A finite analysis model was developed which accounts for the following properties of filled composites microstructure, effect of particle shape, formation of conductive chains, effect of filler aspect ratio, and interfacial thermal resistance. The predictions of the model indicate the most... 

A dataset containing the dielectric constants of 61 polymers measured at room temperature was prepared by careful comparison and combination of the data provided by many sources [3,14-20]. For polar polymers, special care was exercised to select values of e which represented, whenever possible, the "intrinsic" properties of the polymers, rather than the effects of the additives and fillers used. It will be seen in Section 9.D that the dielectric constants of typical commercial grades of many polar polymers, which contain significant amounts of additives, are considerably higher than the "intrinsic" values used in this section. 

For a given polymeric structure, the morphology (crystallinity and orientation), formulation (additives, fillers and impurities), humidity (especially for polar polymers), temperature, and pressure, are the most important factors which affect the thennal conductivity. References [1-8] review many of these factors. In addition, see Bigg [14] and Ross et al [15] for detailed treatments of the effects of fillers and of pressure, respectively, on thermal conductivity. 

TABLE 17.6 Effect of filler and additives in HDPE (MEI 0.48 g/10 min) on the consistency index (j/o) [zero viscosity] and power-law index (n) determined in the parallel plate (dynamic shear) rheometer... 

F. Mijangos-Santiago and J.M. Dealy. Effect of filler content and additives on the extru-date swell of polyethylene pipe resin. Polym. Eng. Sci. 1991,31(16), 1176-1181. 

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