采用溶解浆副产品制备含半纤维素高分子聚合物的机理及其在造纸中的应用基础研究

In this project, the preparation of novel hemicellulose containing monomer by non-aqueous enzymatic method will be explored using of by-products in dissolving pulp production process as raw materials. Combined with the analysis of the changes in the enzyme molecules under different conditions, the characteristics of the solvent system and the substrate, distribution of the product and by-products, the product yield, the regioselectivity and stability of the enzyme in hemicellulose polysaccharides esterification reaction in different non-aqueous medium system will be characterized. The molecular basis of the influence of solvent medium on regioselectivity of polysaccharides esterification will be revealed. A series of new hemicellulose containing polymers were prepared by free radical polymerization and its application in the beating, paper strength reinforce were also discussed. In addition, the preparation of macromolecular initiator, using hemicellulose as the backbone was synthesized and new star or comb polymers by ATRP or SET-LRP will also be originally researched. The applications of new polymers in retention and water treatment in the papermaking process will be studied. This research work focuses on building a new biocatalysis system for preparation of paper-making chemicals with biorefining by-products or product, in order to decreasing environmental pollution generated by the dissolving pulp，the consumption of petrol resources, providing technological innovation and theoretical support for the sustainable socio-economic development of paper-making industries

本项目研究中利用溶解浆生产过程中产生的纤维素类副产品为原料，采用非水相酶催化法制备含纤维素的单体，结合不同条件下酶分子结构、溶剂体系性质及底物、产物等在反应体系中分配规律的研究，阐明不同离子液体或有机溶剂体系对酶促半纤维素聚糖酯化反应的活性、区域选择性、产率及酶稳定性的影响规律；揭示溶剂体系及相关因素对区域选择性糖类酯化反应影响的分子基础；采用自由基聚合制备一系列新型含糖高分子聚合物，研究其在打浆、纤维增强等方面的应用。并以半纤维素为骨架通过制备大分子引发剂，再通过ATRP或SET-LRP法制备星形或梳状新型聚合物，将其应用在造纸过程中的助留和水处理等。本项目着眼于探索利用半纤维素为原料构建生物精炼产生的副产品或产品制备可降解的新型造纸化学品及绿色生物催化方法在该合成反应中的新应用，减少溶解浆产生的环境污染，为降低石油资源消耗、实现新型工业经济模式提供技术。

本项目研究中利用溶解浆生产过程中产生的半纤维素、纤维素类副产品为原料，采用非水相酶催化法制备含寡糖和二糖的单体，结合不同条件下酶分子结构、溶剂体系性质及底物、产物等在反应体系中分配规律的研究，在此基础上阐明了不同混合离子液体或混合有机溶剂体系对酶促半纤维素、纤维素及其糖类降解产物等多羟基化合物的酯化反应的活性、区域选择性、产率及酶稳定性的影响规律，并制备了一系列的纤维素酯化和含糖单体产物；在此基础上揭示溶剂体系及相关因素对区域选择性糖类酯化反应的影响机理；采用自由基聚合制备了一系列新型含寡糖和二糖高分子聚合物，并研究了其在打浆、纤维增强等方面的应用。以纤维素纤维、再生纤维素球为载体成功的制备了固定化果胶酶，此外，以米曲霉、黑曲霉制备了全细胞催化剂，并将其成功地应用制浆造纸过程水处理，实验室研究表明，该类生物制剂可取代来源于石化产品的高分子聚合物，对降低造纸白水的阳离子需求量及树脂沉积的作用明显。本项目着眼于探索利用半纤维素、纤维素为原料构建生物精炼产生的副产品或产品制备可降解的新型造纸化学品及绿色生物催化方法在该合成反应中的新应用，减少制浆造纸工业及溶解浆生产过程中产生的环境污染，为降低石油资源消耗、拓展半纤维素、纤维素类及其衍生物产品的应用范围，实现新型工业经济模式提供了技术和理论支持。