氧化淀粉磷酸酯的微波法制备及其在涂布纸中的应用
发布时间：2019-06-07 20:37
【摘要】： 随着科学技术的发展,物理方法在变性淀粉制备中的地位越来越重要。通过物理方法处理的淀粉,不含化学试剂的残留,其产品的理化性质得到明显改善,产品应用范围和附加值也大大提高。微波处理具有加热速度快、加热均匀性好、易于瞬时控制、选择性吸收以及加热频率高等基本特性,目前作为一种方便、节时的加热能源广泛应用到食品和化工领域。 本论文以玉米原淀粉为原料,分别用过氧化氢和混合磷酸盐为氧化剂和酯化剂,采用微波作为加热介质制备了氧化淀粉磷酸酯。考察了微波功率,催化剂用量,反应温度,反应时间和pH值对氧化淀粉性能的影响;在此基础上,以制备的氧化淀粉为材料,进而考察了微波功率、磷酸盐配比、尿素添加量、反应温度和反应时间对氧化淀粉磷酸酯性能的影响,并确定了氧化淀粉磷酸酯较佳的制备工艺参数;氧化反应条件为:微波功率为500W,催化剂用量为0.08%,反应温度为45℃,氧化时间为30 min,pH值为3.5左右;酯化反应条件为:微波功率为800W,NaH2PO4/Na2HPO4比例为2:1,尿素用量为4%,反应温度为140℃,反应时间为30min。 通过红外光谱(FTIR)、X-射线衍射仪(XRD)、差示扫描量热仪(DSC)、偏光显微镜(PLM)、、扫描电子显微镜(SEM)及旋转式粘度计等检测仪器,分析了改性前后淀粉的分子结构、结晶结构、颗粒形貌和糊的性质;分析表明:微波法所制备的最终产物为氧化淀粉磷酸酯,对原淀粉进行氧化和酯化改性后并没有彻底改变淀粉颗粒的结晶结构,但对其结晶结构产生了一定程度上的破坏,使其熔融温度下降、熔融过程延长;改性后的淀粉颗粒表面发生了非常明显的变化,不仅棱角变钝,而且表面出现了孔洞,说明改性不仅发生在颗粒的表面,而且进入了颗粒的内部;改性后淀粉的糊化温度有所降低,氧化淀粉磷酸酯糊的粘度较氧化淀粉大,但稳定性增强。 为了实现淀粉对胶乳的部分或全部替代,探讨了实验制备的不同氧化淀粉磷酸酯样品及其添加量对涂布纸性能的影响,并对涂料流变性能和保水性能进行了研究。本实验制备的氧化淀粉磷酸酯的涂布纸性较好,其与胶乳的较佳配比为4:10或3:10,最佳干燥温度应控制在85℃为宜;氧化淀粉磷酸酯的涂布纸综合性能优于氧化淀粉和市售的3S涂布淀粉;氧化淀粉磷酸酯的添加并没有改变涂料的剪切稀化特性,但使涂料的表现粘度提高;涂料粘弹性能测试表明:氧化淀粉磷酸酯的添加使涂料组分间相互作用增强,但添加量不宜太大;与纯胶乳配方涂料相比,添加氧化淀粉磷酸酯的涂料的失水量明显下降,由108.32g/m2下降到最小的63.86g/m2,下降幅度约为41%,说明涂料中添加一定量氧化淀粉磷酸酯能明显提高涂料的保水性能。
[Abstract]:With the development of science and technology, physical methods play a more and more important role in the preparation of modified starch. The physical and chemical properties of starch treated by physical method without the residue of chemical reagent were obviously improved, and the application range and added value of the product were also greatly improved. Microwave treatment has many basic characteristics, such as fast heating speed, good heating uniformity, easy instantaneous control, selective absorption and high heating frequency. At present, as a convenient and time-saving heating energy, it is widely used in the field of food and chemical industry. In this paper, oxidized starch phosphate was prepared by using raw corn starch as raw material, hydrogen peroxide and mixed phosphate as oxidant and esterification agent, microwave as heating medium. The effects of microwave power, catalyst dosage, reaction temperature, reaction time and pH value on the properties of oxidized starch were investigated. On this basis, the effects of microwave power, phosphate ratio, urea addition, reaction temperature and reaction time on the properties of oxidized starch phosphate were investigated. The optimum preparation parameters of oxidized starch phosphate were determined. The oxidation conditions are as follows: microwave power 500W, catalyst dosage 0.08%, reaction temperature 45 鈩，
本文编号：2495069
[Abstract]:With the development of science and technology, physical methods play a more and more important role in the preparation of modified starch. The physical and chemical properties of starch treated by physical method without the residue of chemical reagent were obviously improved, and the application range and added value of the product were also greatly improved. Microwave treatment has many basic characteristics, such as fast heating speed, good heating uniformity, easy instantaneous control, selective absorption and high heating frequency. At present, as a convenient and time-saving heating energy, it is widely used in the field of food and chemical industry. In this paper, oxidized starch phosphate was prepared by using raw corn starch as raw material, hydrogen peroxide and mixed phosphate as oxidant and esterification agent, microwave as heating medium. The effects of microwave power, catalyst dosage, reaction temperature, reaction time and pH value on the properties of oxidized starch were investigated. On this basis, the effects of microwave power, phosphate ratio, urea addition, reaction temperature and reaction time on the properties of oxidized starch phosphate were investigated. The optimum preparation parameters of oxidized starch phosphate were determined. The oxidation conditions are as follows: microwave power 500W, catalyst dosage 0.08%, reaction temperature 45 鈩，
本文编号：2495069
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