High density polyethylene/micro calcium carbonate composites: A study of the morphological, thermal, and viscoelastic properties

Abstract

High density polyethylene (HDPE) with micro calcium carbonate (CaCO 3 ) masterbatch was pelletized by using a twin screw extruder and different ASTM specimens were molded by an injection molding machine. The morphology of the composites was characterized by scanning electron microscopy (SEM) and Image Analysis software. The dispersion and interfacial interaction between CaCO 3 and the polymer matrix were also investigated by SEM. The thermal properties of HDPE and its composites were investigated by differential scanning calorimetry (DSC). The crystallization process of the composites samples was found to be slightly different than that of the neat HDPE. Otherwise, the presence of CaCO 3 did not have a considerable effect on the melting behavior of the composites. Thermogravimetric analysis (TGA) revealed that the composites had better thermal stability than the neat HDPE resin as indicated by a higher temperature of 50% weight loss (T 50% ) for the composites as compared to that of the neat resin. The viscoelastic properties of the composites and HDPE were also investigated via torsional and rotational techniques. The presence of CaCO 3 increased the shear modulus at low frequency of the composites at 80 C over that of the neat resin. However, at higher frequencies, the difference between the neat resin and the composites' shear modulus was less than that at low frequencies. The complex viscosity of the composite increased upon the addition of CaCO 3 . However, the shear sensitivities of the neat resin and the microcomposite were similar.

Toughness of HDPE/CaCO3 microcomposites prepared from masterbatch by melt blend method

“…Moreover, agglomerization is well-known phenomenon in CaCO 3 , 32 and the tendency of the nano/ micro CaCO 3 to agglomerate increased the effect of the stress concentration where bigger debonding area has higher stresses than the small ones as shown in Figure 7. In addition, our earlier publication 31,32 we showed that there are larger size CaCO 3 for higher loadings of CaCO 3 than that of smaller loading. We also observed that the processing condition employed for the preparation of these composite was not enough to break the agglomerization at higher % loading of CaCO 3 .…”

“…Figure 2 shows that yield stress decreases with increasing the % loading of CaCO 3 . In our previous work, 31 we showed that CaCO 3 agglomerates in samples of composites with higher CaCO 3 loading. Visual observation of deforming specimens of the composites samples showed that yield and plastic flow is accompanied by very strong whitening of the sample in the necking zone for all compositions with CaCO 3 .…”

Probing of dielectric properties of high density poly-ethylene/calcium carbonate (HDPE/CaCO3) nano-micro composite

“…The melting was at 235°C under pressure of 7.0 bars. The extrudate was cooled in a water bath, dried and palletized for further use (Elleithy et al, 2010). Flat sheets 100 mm wide, 110 mm long and 1 mm thick were injection molded for the purpose of testing.…”

Morphology and Properties of Acrylonitrile‐Butadiene‐Styrene/ZnO Nanocomposites with Compatibilizer

“…[2] The nanoparticles have a high surface to volume ratio and provide highenergy surfaces because of their small size, thus nanoparticles usually are difficult to disperse and agglomerate in the polymer matrix. [3][4][5][6] Agglomeration has a bad effect to the properties of polymer nanocomposites. Therefore, the compatibilizer is needed to improve the dispersion of the nanoparticles and interfacial adhesion between the polymer matrix and filler.…”