Rheological Behaviour of Polypropylene/Kenaf Fibre Composite: Effect of Fibre Size

Abstract

In evaluating thermoplastics for their effective performance during processing, rheology properties are very useful. Similarly, in designing processing apparatus, knowledge of rheological behavior of composite melt is critical. In this study, melt flow and viscosity behavior of polypropylene/kenaf fibre composite was investigated using a single-screw extruder. Subsequently, flow behavior of the compounded formulation were evaluated by comparing the melt flow index, flow curve and viscosity curve of the PP and that of the composites at 190oC processing temperature and varying the fibre size. There appears to be a positive linear increase of the apparent shear stress with increase in the apparent shear rate and, as expected, viscosity values for the composite samples are much higher than the PP especially at larger fibre size. The additional of kenaf fibre in composite reduces the MFI value basically because of the hindrances in the plastic flow of the polymer. In addition the increase in viscosity with increase in fibre loading might contributed to the high specific area of the fibre in the matrix thereby increasing the shear stress in the composite. Moreover loading of polymer system with fibre tends to disturb or disorganize the normal free movement of the polymer and certainly hindered the mobility chain segments in flow.

Melt volume flow rate and melt flow rate of kenaf fibre reinforced Floreon/magnesium hydroxide biocomposites

“…Ersoy and Taşdemir ( 2012 ) indicated a more than 52.22 % decline of MFR from 0 to 20 wt% of MH filled composites. By increasing the MH content from 5 to 10 wt% (sample 4–5), the MH particles formed new network junctions in the composites, resulting in better interaction forces and friction forces (Crowson et al 1980 ; Khalina et al 2011 ). Therefore lower MVR and MFR values for the composites were found with increasing MH contents (Liang et al 2000 ).…”

Studies on the properties of polypropylene/(waste tire dust)/kenaf (PP/WTD/KNF) composites with addition of phthalic anhydride (PA) as a function of KNF loading

“…In Malaysia, KNF crops have been planted in large numbers to replace tobacco and are widely studied to sustain the development of new applications of KNF crops . There are numerous studies on (KNF fiber)‐filled polymer composites being investigated and reported . The utilization of KNF fiber in polymer composites applications can help in solving waste management on disposal, hence protecting the environment.…”

Influence of kenaf form and loading on the properties of kenaf‐filled polypropylene/waste tire dust composites: A comparison study

“…KNF is a low cost, renewable, and quick growing annual plant, which is used extensively as a filler in polymer composites . For instance, Ismail et al used KNF core fiber as a filler in high‐density polyethylene/soya powder composites and found that the tensile modulus, flexural strength, and flexural modulus of the composites increased with the addition of KNF core.…”