Material utilization and functionalization of lignosulfonic acid via microcompositions with synthetic polymers

由于分离的木质素的低分子量和分子结构，其作为固体材料的利用受到差的成膜性和不足的模塑性的限制。本研究以聚乙烯吡咯烷酮（PVP）为增容剂，制备了含二磺酸（LSA）的醋酸纤维素（CA）复合材料和LSA/聚乙烯醇（PVA）复合水凝胶。对于复合材料（1），LSA通过与PVP的乙烯基吡咯烷酮单元的氢键作用有效地引入到复合材料中。采用Freundlich和Langmuir吸附模型对复合材料的吸附性能进行了评价，结果表明复合材料中LSA与尼古丁之间存在较强的相互作用。另一方面，对于（2）的方法，通过热处理或与戊二醛反应引入交联部分。通过热交联，LSA和PVA之间形成氢键和磺酸酯，可以防止LSA在水介质中洗脱，这两者都被FT-IR测量所证实。热处理的复合水凝胶表现出尼古丁在生理盐水溶液中的缓释行为。另一方面，采用聚乙二醇二缩水甘油醚作为交联剂对LSA进行预交联，以提高水介质中化学交联法制备的LSA/PVA复合水凝胶中LSA的含量。因此，引入连接的LSA实现了复合水凝胶的保水性能的大幅度提高，其中蒸馏水的最大保持率大于其自身重量的500倍。

Utilization of isolated lignins as a solid material is constrained by poor film formability and insufficient moldability due to their low molecular weight and molecular structure. In the present study, we prepared (1) ignosulfonic acid (LSA)-containing composites with cellulose acetate (CA) via poly(N-vinyl pyrrolidone) (PVP) as a compatibilzier and (2) LSA/poly(vinyl alcohol) (PVA) composite hydrogels. For the composite (1), LSA was effectively incorporated into the composites via hydrogen bonding with vinylpyrrolidone unit of PVP. Adsorption property of the composites to catch nicotine was evaluated with Freundlich and Langmuir models, which revealed the occurrence of a strong interaction between LSA and nicotine. On the other hand, for the approach of (2), cross-linking moiety was introduced by thermal treatment or reaction with glutaraldehyde. By thermal cross-linking, an elution of LSA in aqueous media could be prevented by formations of hydrogen bonding and sulfonate ester between LSA and PVA, both of which were corroborated by FT-IR measurement. The thermal-treated composite hydrogels demonstrated a sustained-release behavior of nicotine in normal saline solution. On the other hand, pre-interlinking of LSA was performed using poly(ethylene glycol) diglycidyl ether as a linking agent, in order to improve the LSA content for the LSA/PVA composite hydrogel prepared via chemical cross-linking in aqueous media. Thereupon, the incorporation of linked-LSA achieved much improvement of water retentivity for the composite hydrogels, where the maximum retentivity of distilled water was > 500 times its own weight.