【作者】 樊燕鸽；

【导师】 熊汉国；

【作者基本信息】 华中农业大学 ， 食品科学， 2007， 硕士

【摘要】 薄膜和包装材料在塑料垃圾中占有相当大的比例，用具有良好生物降解性能的薄膜材料替代它们既可减轻白色污染又可缓解石油资源短缺。淀粉基生物降解塑料薄膜是一种重要的可降解高分子材料。本论文在保证材料生物可降解性的同时，改善材料的力学性和耐水性。主要内容包括磷酸酯多孔淀粉的制备和淀粉基生物降解塑料薄膜的制备。多孔淀粉比原淀粉具有更大的表面积和更多的活性羟基，采用多孔淀粉以干法制备磷酸酯淀粉可有效的提高产品取代度，其冻融稳定性、抗剪切性、热稳定性以及与PVA的相容性也得到改善。对改性淀粉进行增强、增塑和交联处理后，采用模压工艺生产的生物降解膜力学性能得到改善，生物降解性也有所提高。1以淀粉酶在淀粉糊化温度以下水解淀粉，得到多孔淀粉。最佳制备条件为：pH5.2，酶用量1％（占淀粉质量百分比），反应时间6h，反应温度50℃。2采用更加环保的干法工艺生产磷酸酯多孔淀粉，通过五因素二次正交旋转组合试验得出磷酸盐含量、尿素含量、pH值、反应温度、反应时间对取代度影响关系的五元二次回归方程：Y=-2.2814-0.02248Z₁+0.02436Z₂+0.320223+0.00268Z₄+0.3881Z₅+0.00376Z₁Z₂-0．00357Z₁Z₅+0.00335Z₂Z₃+0.01132Z₂Z₄-0.00171Z₃Z₄-0.04016Z₃Z₅-0.00631Z₄Z₅+0.00147Z₁²-0.00290Z₃²。3确定淀粉与PVA用量为7∶3。（质量比）增塑剂：水15％、甘油20％、聚乙二醇15％；（占淀粉质量百分比）交联剂：六次甲基四胺1.5％、硼酸2％；单硬脂酸甘油酯0.6％；尿素3.5％。（占淀粉与PVA总质量的百分比）4采用三因素二次正交旋转组合试验得出加热温度、模压压力、保压时间对生物降解膜性能影响关系的三元二次回归方程：Y=-1374.78+13.43Z₁-7.31Z₂-46.13Z₃-0.52Z₁Z₃+0.87Z₂Z₃-0.242Z₂²。5红外光谱和X-射线衍射的结构分析表明：在改性淀粉的羟基上引入了磷酰基团，并未破坏原淀粉的基本化学结构；交联剂在改性淀粉和PVA之间形成了C-O-C化学交联键；酯化和交联反应均有较强的淀粉晶区破坏作用。6利用土埋法进行生物降解试验，结果表明150d时，生物降解膜失重率可达到60％。更多还原

【Abstract】 Film, ground film and packing materials possess a large proportion in plastic garbage. To replace them with film material with good degradability can alleviate the white pollution and the petroleum resource shortage. Starch-based biodegradable plastic film is a kind of important degradable polymer material. This paper will focus on how to improve the mechanical properties and water-resistance of the material, at the same time ensuring its biodegradability. The major work includes the preparation of phosphate porous starch and the starch-film.Porous starch has more surface area and hydroxyl group than native starch. In this paper it has been proved that many properties of starch and starch material, such as freeze-thaw stability, resist shearing, heat-resistant stability, and consistency with PVA, can be improved greatly when starch is modified by hydrolytic and phosphorylation, and many properties of starch film, such as tensile strength, water-resistance and biodegradability also can be improved greatly when metamorphic starch is cross linked, plasticized, strengthened at the same time.1 The optimum hydrolytic conditions were as follows: pH 5.2, the quantity ofα-amylase 1%, reaction time 6h, reaction temperature 50℃.2 By means of quadratic component rotational design, the experiment was conducted in order to get an optimized preparation scheme for degree of substitution （DS）. Y=-2.2814-0.02248Z₁+0.02436Z₂+0.3202Z₃+0.00268Z₄+0.3881Z₅+0.00376Z₁Z₂-0.00357Z₁Z₅+0.00335Z₂Z₃+0.01132Z₂Z₄-0.00171Z₃Z₄-0.04016Z₃Z₅-0.00631Z₄Z₅+0.00147Z₁²-0.00290Z₃²。3 The optimum preparation starch film conditions were as follows: starch: PVA was 7:3, water 15%, glycerol 20%, polymeric glycol 15%, methenamine 1.5%, boric acid 2%, glyceryl monostearate 0.6%, urea 3.5%.4 By means of quadratic component rotational design, the experiment was conducted in order to get an optimized preparation scheme for starch film. Y=-1374.78+13.43Z¹-7.31Z₂-46.13Z₃-0.52Z₁Z₃+0.87Z₂Z₃-0.24Z₂²。5 The structural characteristics of the films were investigated by infrared spectroscopy（IR） and X-ray diffraction. The results demonstrated that: phosphate groups were linked with the anhydrous glucose units. Phosphate porous starch and PVA were cross linked by methenamine and boric acid Crystal area was serious destroyed by esterification and cross linked.6 Biodegradation experiment was carried out with soil-burying method. The result showed that the ratio of lose weight of starch film is 60% after 150 days under the soil.更多还原