Ca^(2+)交联羧基化麦草秸秆化机浆的制备及性能研究

Study on Preparation and Properties of Ca^(2+)-Crosslinked Carboxylated Wheat Straw Chemi-mechanical Pulp

本研究采用TEMPO氧化体系,转化麦草秸秆化机浆(SP)纤维素C6位上的羟基为羧基,制备羧基化麦草秸秆化机浆(CSP);对CSP进行Ca^(2+)交联,制备Ca^(2+)交联羧基化麦草秸秆化机浆(CSP@Ca^(2+)),探究其纸浆的物理强度性能。基于FT-IR、XPS等手段可以明显检测CSP纤维的羰基/羧基官能团:羧基化1 h麦草秸秆化机浆纤维(CSP1)的羧酸含量为0.27 mmol/g,其Zeta电位从SP的-21.7 mV变化为-29.2 mV,这为Ca^(2+)的交联提供作用位点。纸张物理强度结果表明,CSP1@Ca^(2+)0.5的抗张指数、耐破指数和撕裂指数分别较SP提高154.4%、170.8%和12.9%。最终,CSP1@Ca^(2+)0.5与SP配抄纸张(配抄比例为50∶50)的抗张指数、耐破指数和撕裂指数分别达27.1 N·m/g、2.28 kPa·m^(2)/g和3.68 mN·m^(2)/g,较SP分别提高83.4%、115.1%和8.3%。

In this study,TEMPO oxidation was used to transform the hydroxyl group at C6 position of wheat straw pulp(SP)cellulose into carboxyl group to prepare carboxylated wheat straw pulp(CSP).Ca^(2+)crosslinked carboxylated wheat straw pulp(CSP@Ca^(2+))was prepared by crosslinking CSP with Ca^(2+),and its strength properties were explored.The carboxyl/carbonyl groups of CSP fibers were determined by using FT-IR and XPS:the carboxyl group content of CSP carboxylated for 1 h(CSP1)was 0.27 mmol/g and its Zeta potential varied from−21.71 to−29.2 mV,which provided reactive sites for Ca^(2+)crosslinking.Compared with SP,tensile,burst,and tear indexes of CSP1@Ca^(2+)0.5 improved by 154.4%,170.8%,and 12.9%,respectively.Tensile,burst,and tear indexes of the mixed CSP@Ca^(2+)0.5/SP(50∶50)paper were 27.1 N·m/g,2.28 kPa·m^(2)/g,and 3.68 mN·m^(2)/g,increased by 83.4%,115.1% and 8.3%,respectively,compared with SP.