Dual-surface modification of calcium sulfate whisker with sodium hexametaphosphate/silica and use as new water-resistant reinforcing fillers in papermaking
Published:1 February 2015
DOI: 10.1016/j.powtec.2014.11.015
Xin Feng , Ying Zhang , Gangling Wang , Miao Miao , Liyi Shi
Abstract
Inorganic calcium sulfate whisker (CSW) was surface modified with sodium hexametaphosphate (SHP) as waterproof modifier to reduce the solubility, and subsequently CSW/SHP was further modified using the coating of silica to improve water tolerant and enhance the bondability between CSW and wood fibers. Through the dual-surface modification, electrical conductivity (EC) of the pure unmodified CSW decreased dramatically and reached an equilibrium value of 73.9?μs·cm???1 in the CSW/SHP/SiO2 solution. The mechanical properties of hybrid handsheets containing 2.5–20?wt.% modified fillers were investigated, and the retention of the modified fillers was higher than that of unmodified fillers.