| Abstract:The common sizing agent, alkylketene dimer (AKD), and the coating binder carboxylated styrene-butadiene latex (XSBRL), were taken as model compounds of microstickies in whitewater to investigate their stability characteristics in the liquid phase. The basic characteristics of AKD and XSBRL were characterized by Infrared Spectrometric Analyzer (FT-IR) and Scanning Electron Microscopy (SEM), and the thermal properties were analyzed through differential scanning calorimetry (DSC) and thermogravimetry (TG). Furthermore, the effects of the conditions of papermaking system on the change of the particle size distribution were investigated by using a method combining laser, flow cytometric technology and fluorescent tracers. The results showed that both of the two model compounds were sticky and in high elastic state in the temperature range of papermaking system compared with in glass state at room temperature, which induced the aggregation among particles. XSBRL was more sensitive to temperature and its aggregation degree was higher than AKD’s. With the temperature increasing, the aggregation tendencies of these two model compounds were slightly increased. When the system temperature was kept at 50℃, the aggregation state of the two model compounds increased slightly and changed marginally with time went on. The effect of mechanical agitation on the particle size distribution of the two model compounds was related to the strength of agitation. The particles of the two model compounds didn’t slightly aggregate anymore and tended to disperse when the stirring speed exceeded 800 r/min. |
