title: Further understanding on the mechanism of alkyl ketene dimer sizing on the causticized calcium carbonate filled paper and its improvements.
abstract: Causticized calcium carbonate (CCC), a solid waste derived from kraft black recovery process, can be used as an alternative for the conventional precipitated calcium carbonate (PCC). However, the application of the CCC has been limited due to its low sizing efficiency in its filled paper. In this study, the characteristics of the CCC were studied aiming to improve the alkyl ketene dimer (AKD) sizing performances of the CCC filled papers, and the results were compared with those from PCC filled papers. The results showed that the CCC had higher pore structure, higher specific surface area, and more negative charge density than the PCC, thus leading to a higher cationic AKD adsorption onto the CCC filler. The lower AKD sizing efficiency in the CCC filled paper can be explained by the combination of higher AKD adsorption and migration, both of which resulted in preferred AKD adsorption onto/into the CCC fillers, rather than the cellulose fibers. Based on the above, the prior addition of polyamide-polyamine epichlorhydrin (PAE) resin to the CCC filler system was proposed to remedy the related issues, thus improving the sizing efficiency.
authors.affiliation: College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China. zzwangjian@sust.edu.cn.|State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China. zzwangjian@sust.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Dang
authors.affiliation: College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Duan
authors.affiliation: College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, China.
authors.forename: Li
authors.initials: L
authors.lastname: Qian
mesh_terms: D000327:Adsorption; D002119:Calcium Carbonate / Q000737:chemistry*; D019281:Dimerization; D005030:Ethylenes / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D010209:Paper; D062611:Solid Waste
chemical_list: D005030:Ethylenes; D007659:Ketones; D062611:Solid Waste; D002119:Calcium Carbonate; C008223:ketene
keywords: AKD sizing efficiency; Adsorption mechanism; Causticized calcium carbonate; Filler; Migration mechanism; Solid waste