碱回收白泥精制碳酸钙对AKD施胶剂的吸附特性研究

Adsorption Behaviour of Alkyl Ketene Dimer on Lime Mud Calcium Carbonate

关键词:  白泥精制碳酸钙  商品碳酸钙  AKD施胶  吸附特性

Key Words:lime mud  commercial calcium carbonate  alkyl ketene dimmer  adsorption behaviour

摘要:用紫外分光光度法和颗粒电荷滴定法测定了几种碱回收白泥精制碳酸钙（LMCC）和商品碳酸钙（包括PCC1、PCC3、GCC1和GCC2）填料对AKD施胶剂的吸附特性。结果显示，LMCC和GCC1对AKD的吸附量高于实验用其他商品碳酸钙， GCC1的比表面积远低于LMCC，但其AKD吸附量却高于LMCC，这可能与填料的电荷特性密切相关。LMCC加填后成纸的施胶度最差，且随干燥温度的增加LMCC对AKD施胶的负面影响增加，AKD吸附量最高的GCC1加填纸的施胶度远高于LMCC加填纸，这与通常所认为的吸附量越高的填料对AKD施胶的影响越大相矛盾，有可能LMCC对AKD施胶的影响并非单纯的吸附原因。

Abstract:UV spectrophotometry and particle charge titration were used to measure the adsorption isotherms of AKD on different lime mud calcium carbonates. The same measurements were also conducted with various commercial calcium carbonates (include PCC1、 PCC3、 GCC1 and GCC2) for comparison. The results showed that more AKD particles were absorbed on lime mud calcium carbonates and GCC1 than other commercial fillers used in the experiment. Although lime mud calcium carbonates have higher specific surface area, they tend to absorb less AKD than GCC1 which has lower specific surface area, this probably relates to the charge density of the fillers. The sizing degree of the papers containing different fillers was expressed as Cobb value, the results showed that samples loaded with lime mud calcium carbonate had the maximum Cobb value，and the negative influence of lime mud calcium carbonates on AKD sizing was obvious as the drying temperature increased. Fine GCC had the maximum adsorption of AKD, the sizing degree of paper filled with fine GCC was much higher than the papers filled with lime mud calcium carbonates. This implies that adsorption is not the only main reason for low sizing efficiency.