What effect would decreasing melt viscosity by increasing melt temperature have on filler disaggregation in an extruder/compounder?

PLA has a melting point of around 150-160 degrees Celcius (the grade I am working with). I have microcellulosic fillers with aspect ratios that I am introducing to the polymer for compounding in a Brabender single screw compounder with an L/D of 25:1 and two mixing zones in the screw. Due to a low affinity between the hydrophobic matrix and the hydrophilic filler phase, there's an aggregation of microcellulosic fillers. The extrudate is in the form of a 1.5-2 mm diameter filament. Microstructure analysis shows that some degree of aggregation persists even after I run the chipped composite filament a second time through the melt extruder/compounder.


1. I am wondering what would be the effect of reducing the melt viscosity by increasing the processing temperature to something like 230 degrees Celcius on the filler aggregation? Please do note that this temperature is within the safe range where neither the PLA nor microcellulosic filler I am using degrades.
2. Should I instead try to process the extrudate at a lower processing temperature which would not decrease the melt viscosity and hence subject the microcellulosic aggregates to higher shear stresses in the extruder, thereby facilitating filler disaggregation?


