玉米秸秆液化制备生物高聚物材料的研究(英)

该研究旨在探讨低温生物质液化技术及液化产物应用的可能性。以玉米秸秆为原料在酸性、常压条件下快速液化成多羟基化合物，再以多羟基化合物为原料合成一系列的聚合材料。采用不同的有机溶剂，在稀硫酸的催化作用下，对不同的温度下生物质的液化效果进行研究。同时探讨了液化有机溶剂同生物质物料的混合比率对液化过程的影响。试验表明，碳酸乙烯酯比乙烯醇具有较高的液化率。优化试验结果表明，在较佳的液化效果下， 有机溶剂同玉米秆的混合比率为3∶1，反应温度160℃，稀硫酸浓度3%，反应时间2.5 h。液化产物经稀释、调节pH值、过滤、臭氧氧化一系列过程的处理后得到具有高活性多羟基聚合物。阐述了以多羟基聚合物制备各种生物聚合物材料如聚酯薄膜、聚胺酯泡沫和颗粒板的方法。聚酯薄膜是多羟基化合物上的羟基和多元酸上的羧基通过酯化反应形成的；聚胺酯泡沫通过多羟基化合物上的羟基和二异氰酸酯反应形成。研究表明以多羟基化合物和多元酸（酐）形成的聚酯型胶粘剂适合于制造颗粒板。

Preparation of biopolymers from liquefied corn stover

The objective of the present study was to develop processes for liquefaction of solid biomass and explore the potential of making biopolymers from the liquefied biomass. In this study, corn stover was liquefied under acidic conditions, and several polymer materials were subsequently prepared from the liquefied biomass. Liquefaction was conducted using different organic solvents with sulfuric acid as catalyst at different temperatures. The effect of the ratio of solvent to solid biomass on liquefaction rate was also evaluated. Of the two organic solvents used in the liquefaction process, ethylene carbonate was found to be more effective than ethylene glycol in terms of liquefaction rate. The adequate processing conditions for the feedstock used were found to be organic solvent / corn stover ratio of 3, temperature 160℃, catalyst content3%, and heating time 2.5 hours. The polyols from the liquefaction were separated and purified through a series of processes, such as dilution, pH value adjustment, filtration, evaporation, and ozonolysis. Processes for making biopolymers,such as polyester films, polyurethane foams and particleboards from the liquefied corn stover containing a high quantity of bio-polyols were evaluated. The film formation was based on the esterification reaction between the hydroxyl groups of the bio-polyols and the carboxyl groups. The foam was prepared through a reaction of the hydroxyl groups with diisocyanate.Polyesters made from the reaction between bio-polyols and anhydrides are shown to be a good adhesive for making particleboard.