生物活化改性小麦秸秆纤维素基仿贻贝复合材料的制备

Preparation of biomimetic nacre-like composite based on bioactive modification wheat-straw-fibers

为进一步研究纤维素基结构-功能一体化复合材料,寻求一种简便、快捷和无污染、低成本的方法制备优良性生物基复合材料。通过机械胶膜法将小麦秸秆纤维和贝壳粉体有效的交联一起,再通过无胶热压得到层状结构的仿贻贝复合材料。借助SEM、EDS、FT-IR和XPS对仿贻贝复合材料的形貌结构、化学组分的主要基团和元素变化进行分析。通过机械热胶磨之后,小麦秸秆纤维会分层分支且无胶热压后呈层状结构;仿贻贝复合材料的静曲强度(MOR)、弹性模量(MOE)、内结合强度(IB)分别为29.58、5967和0.888 MPa;吸水厚度膨胀率(TS)仅为0.316%,表现出一定的尺寸稳定性。仿贻贝复合材料的MOR、MOE、IB以及TS均优于其他材料,这主要是由于胶磨过程产生的分层和分支使秸秆纤维素有更多的酯键和氢键,增大了比表面积,更多的羟基裸露,增加了纤维之间的交联作用,从而增大了仿贻贝复合材料的机械强度。

In order to further study cellulose-based structure-functional integrated composites,a simple,fast and pollution-free,low-cost method was sought to prepare bio-based lignocellulosic composites with excellent properties.Wheat-straw-fibers and shell particles could be effectively compounded by mechanical film method.Biomimetic nacre-like composite was obtained by hot-spot.The morphology,structure,chemical components and element variation of the biomimetic nacre-like composite were analyzed by SEM,EDS,FT-IR and XXPS.The results showed that the wheat-straw-fibers were laminated through the grinding and the biomimetic nacre-like composite appeared layered-structure by hot-pressing method under binderless.The MOR,MOE and IB were 29.58 MPa,5967 MPa,0.888 MPa,respectively.Meanwhile,its swelling value of water absorption thickness was 0.361%,showing the dimensional stability.The MOR,MOE,IB and TS of the biomimetic nacre-like composites were superior to other materials,mainly due to the delamination and branching produced by the rubber grinding process,which made the straw cellulose more ester.The bond and hydrogen bond increased the specific surface area,and more hydroxyl groups were exposed,which increased the cross-linking between the fibers,thereby increasing the mechanical strength of the mussel-like composite.