Effect of bark flour on melt rheological behavior of high density polyethylene

Abstract

ABSTRACT:The melt rheological behavior of neem bark flour (BF) filled high density polyethylene (HDPE) has been studied at varying volume fraction (U f ) from 0 to 0.26 at 180, 190, and 200 C in the shear rate range from 100 to 5000 s À1 using extruded pellets of the composites. The melt viscosity of HDPE increases with U f because the BF particles obstruct the flow of HDPE. With the incorporation of the coupling agent HDPE-g-MAH, the viscosity decreased compared to the corresponding compositions in the HDPE/BF systems due to a plasticizing/lubricating effect by HDPE-g-MAH. The composites obeyed power law behavior in the melt flow. The power law index decreases with increase in the filler content and increases with temperature for the corresponding systems while the consistency index showed the opposite trend. The activation energy for viscous flow exhibited inappreciable change with either U f or inclusion of the coupling agent, however, the pre-exponential factor increased with filler concentration.

Evaluation of the Mechanical, Thermal and Rheological Properties of Recycled Polyolefins Rice-hull Composites

“…The MFR of rHDPE <0.5 mm particle size is comparable with the MFR of corn cob composites as reported by Adefisan and McDonald [34]. In the presence of natural fiber fillers, there is the resistance to flow and sliding between the intermolecular layers, causing an increase in melt viscosity [17]. rPP composites MFR were significantly higher, with values of 125 and 109 g/10 min and concomitant lower viscosities of 0.35 and 0.41 kPa.s for <1 mm and <0.5 mm particles, respectively.…”

Influence of filler loading and palm oil‐based green coupling agent on torque rheological properties of polypropylene/cocoa pod husk composites

“…This suggests that the composite compound experienced a lower shear thinning with addition of GCA‐P. A number of researchers conducted torque rheological studies on thermoplastic composites with different natural filler also have the similar observation …”

“…As highlighted in preceding section, the viscosity of composite compound increased at higher filler loading. [22,33,34] Figure 6 shows the viscosity of neat PP and all PP/CPH composites at different shear rate. [32] For composite formulation with addition of GCA-P, higher shear stress of the composite compounds was recorded.…”

“…This suggests that the composite compound experienced a lower shear thinning with addition of GCA-P. A number of researchers conducted torque rheological studies on thermoplastic composites with different natural filler also have the similar observation. [22,33,34] Figure 6 shows the viscosity of neat PP and all PP/CPH composites at different shear rate. At similar shear rate, both composites show an increasing trend in viscosity as the filler loading increases.…”

Rheological Properties of Natural Fiber Polymer Composites

“…Rheology can interpret degree of dispersion of wood fiber, behavior of interfacial region, and polymer-wood fiber affinity and has a vital role in processing of these composites [12,13]. Both capillary and oscillatory rheometers have been reported to generate rheological data for WPC.…”