Study on the surface sizing of modified chitosan and its effect on the properties of dialysis paper

In order to improve the paper properties and enhance the utilization efficiency of functional chemical additives, surface sizing agents were prepared by combining water-soluble maleic anhydride acylated chitosan (MAAC), carboxymethylated chitosan (O-CMCS) and polyvinyl alcohol (PVA), and the effects of sizing process on the surface morphology, physical strength and antimicrobial properties of the dialysis paper were investigated. The results showed that when the coating weight was about 6.5 g/m2 and the dosage of the modified chitosan was about 1.5% of the paper weight, the dry tensile strength, wet tensile strength and burst strength of paper sized with MAAC/PVA sizing agent increased by 46.5%, 82.2% and 107%, respectively, compared to that of unsized paper, while the dry tensile strength, wet tensile strength and burst strength of paper sized with O-CMCS/PVA sizing agent increased by 41.4%, 53.6% and 107%, respectively. In addition, the paper sized with MAAC/PVA and O-CMCS/PVA sizing agent displayed excellent antibacterial effect, which had the antibacterial rate against E. coli of 94.8% and 92.9%, respectively. In a word, the physical strength and antimicrobial properties of paper could be greatly improved by adding a small amount of modified chitosan (CS) to the surface sizing agent, and the strength improvement and antibacterial effect of MAAC/PVA sizing agent were better than that of O-CMCS/PVA.