Effect of cationic polymethacrylates on the rheology and flocculation of microfibrillated cellulose |
| |
Authors: | Anni Karppinen Arja-Helena Vesterinen Tapio Saarinen Pirjo Pietikäinen Jukka Seppälä |
| |
Institution: | (1) School of Chemical Technology, Polymer Technology, Aalto University, P.O. Box 16100, 00076 Aalto, Finland; |
| |
Abstract: | Using two cationic methacrylate polymers: poly(2-(methacryloyloxy)ethyl] trimethyl ammonium iodide) (PDMQ) and poly(stearyl
methacrylate)-stat-(2-(methacryloyloxy)ethyl] trimethyl ammonium iodide)] (PSMA13Q), we modified microfibrillated cellulose (MFC) water suspensions.
The aim was to affect the flocculation and rheological behavior of the MFC suspension. PDMQ is a strongly cationic polymer
while PSMA13Q, also a cationic polymer, contains hydrophobic segments. We studied the MFC/polymer suspension rheological properties
with a rotational rheometer in oscillatory and flow measurements. To observe structural changes in suspensions at different
shear rates, we measured flow curves with transparent outer geometry and photographed the sample with a digital camera. The
oscillatory measurements showed that a small amount of the cationic PDMQ in the MFC suspension strengthened the gel, whereas
a small amount of amphiphilic PSMA13Q weakened it. Increased amounts of either polymer increased the gel strength. PSMA13Q
also changed the rheological character of the MFC suspension turning it more fluid-like. When we photographed the flow curve
measurement, we saw a clear change in the floc structure. This floc structure rupture coincided with a transient region in
the flow curve. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|