| Abstract:Relatively pure xylan was extracted from poplar, and treated with acid to prepare the samples with different molecular weights. The xylan was characterized by HPLC and GPC. All of the xylan hemicelluloses samples were used to improve pulp strength as wet-end additive and surface sizing agent. The results showed that xylan can improve the physical properties of handsheets significantly, and the xylan with larger molecular weight has better paper-strengthening effects. It also showed that the surface sizing results are better by using xylan to replace starch partly. The best formula of surface sizing agent is 4% xylan+4% starch, and the tensile index, tear index, folding endurance and water-resistant performance of sized handsheets increase by 56.0%, 17.1%, 10.7 times and 39.6%, respectively, compared to those of the control. |
