对甲苯磺酸预处理对纳米纤维素膜性能的影响

Effect of p-Toluenesulfonic Acid Pretreatment on Properties of Nanocellulose Film

中文关键词:  对甲苯磺酸  木质素  纳米纤维素纤丝

Key Words:p-toluenesulfonic acid  lignin  cellulose nanofibril

中文摘要:

      利用两步对甲苯磺酸（p-TsOH）预处理选择性分离蔗渣中的半纤维素和木质素，并对p-TsOH预处理的剩余固体和商业级漂白蔗渣浆进行高压均质处理，获得2种纤维素纳米纤丝（LCNF和BCNF）；然后对LCNF和BCNF进行真空抽滤及热压（T）处理，制得不同的纳米纤维素膜（LCNF膜、BCNF膜、T-LCNF膜和T-BCNF膜）。结果表明，p-TsOH预处理后残留的木质素有利于CNF的制备和分散，且可提高CNF滤水性能，使其成膜性大幅提升；此外，木质素的存在可显著提高CNF膜的疏水性，但对其力学性能有一定阻碍作用；通过热压作用可实现木质素的热熔和再分布，改变CNF膜的结构，使其拉伸强度大幅提高（166.7 MPa）的同时具有良好的疏水性。

Abstract:

      Hemicellulose and lignin in bagasse were selectively separated by two-step p-toluenesulfonic acid （p-TsOH） pretreatment. The residual solids from p-TsOH pretreatment and bleached bagasse pulp were homogenized at high pressure to prepare cellulose nanofibril with and without lignin （LCNF and BCNF）. LCNF and BCNF were further treated with vacuum filtration and hot pressing （T） to prepare different CNF films （LCNF film， BCNF film， T-LCNF film， and T-BCNF film）. The results show that the residual lignin after p-TsOH pretreatment is conducive to the preparation and dispersion of CNF and can improve water filtration performance of CNF， rendering a great improvement in film formation of CNF. In addition， the residual lignin significantly improves the hydrophobicity of CNF films but has a certain hindrance to its mechanical properties. However， lignin can be hot-melted and redistributed through hot pressing， and the structure of CNF films thusly changes， so that the tensile strength of the CNF film significantly increases to 166.7 MPa and the film possesses excellent hydrophobicity.