木质素-Ca^(2+)络合物微粒的制备及其改性聚乙烯醇薄膜的研究

Preparation of Lignin-Ca^(2+)Complex Microparticles and Study on Their Modification of Polyvinyl Alcohol Films

木质素作为一种产量丰富的天然有机高分子,其分子结构中存在羰基、酚羟基、醇羟基以及甲氧基等大量的活性官能团,为设计制备含有木质素的新型功能材料提供了可能。文章以玉米秸秆外壳为原料,经pH值为11的碱溶液高温浸泡后,在其木质素提取液中直接加入钙离子(Ca^(2+)),利用Ca^(2+)与木质素分子结构中羰基和醚键等基团的配位作用,制备了具有微米尺度的木质素-Ca^(2+)络合物微粒。将木质素-Ca^(2+)络合物与质量浓度为4%的聚乙烯醇(PVA)水溶液混合,利用溶液浇铸法获得了不同络合物微粒含量的PVA/木质素-Ca^(2+)复合塑料薄膜。结果表明:PVA薄膜在加入木质素-Ca^(2+)络合物微粒后,其拉伸强度、刚性、降解性能、紫外吸收和阻燃性能等均得到不同程度的提高。

As a natural organic polymer with abundant yield,lignin has a large number of active functional groups such as carbonyl,phenolic hydroxyl group,alcohol hydroxyl group and methoxy group in its molecular structure,which provides the possibility for the design and preparation of new functional materials containing lignin.In this paper,the corn straw shell was used as raw material,soaked in alkali solution with pH value of 11 at high temperature,calcium ions(Ca^(2+))were directly added to the lignin extract,and the coordination effect of Ca^(2+)with carbonyl and ether bonds in the molecular structure of lignin was used to prepare micron-scale lignin-Ca^(2+)complex particles.The lignin-Ca^(2+)complex was mixed with an aqueous solution of polyvinyl alcohol(PVA)with a mass concentration of 4%,and PVA/lignin-Ca^(2+)composite plastic films with different complex particle contents were obtained by the solution casting method.The results show that the tensile strength,rigidity,degradation performance,ultraviolet absorption and flame retardancy of PVA film are improved to different degrees after lignin-Ca^(2+)complex particles are added.