基于硼酸与多醇相互作用的纤维素材料表面自组装

发布时间：2018-06-03 11:35

本文选题：苯硼酸 + 聚乙烯醇　；参考：《江南大学》2017年硕士论文

【摘要】：含硼酸官能团类化合物,自从被发现能与1,2-二醇或1,3-二醇形成可逆的硼酸酯以来,在各研究领域都得到了广泛的关注。尤其是对于含苯硼酸官能团类化合物的复合材料的研究,即利用苯硼酸优异的性能与其他材料复合,从而赋予新材料某些优秀的性能。由于自组装技术具有操作简便,成膜不受基材的限制,驱动力多种多样等特点,使其在材料改性方面得到了广泛的研究。本论文以硼酸多醇相互作用为驱动力,在纤维素膜表面进行了自组装研究,主要研究内容由以下三部分组成:1.硼酸改性纤维素膜的制备、表征及性能分析采用2,2,6,6-四甲基哌啶-1-氧基(TEMPO)氧化法及酰胺化反应在纤维素膜表面接枝上了苯硼酸官能团。利用红外光谱法和荧光法对改性纤维素膜进行了表征;利用抗张试验机和耐破度仪对改性纤维素膜的机械性能进行了测试;最后探索了改性纤维素膜对表面含有多醇结构的微球吸附与解吸附性能,结果表明:当TEMPO、NaBr和10 wt%的NaClO溶液的用量分别为0.05 g、0.025 g、4 mL,氧化时间为45 min时,可以获得机械性能较佳的改性纤维素膜,该纤维素膜对含有多醇结构微球的吸附与解吸过程具有pH可控性。2.硼酸改性棕榈蜡乳液微球在纤维素膜上的自组装研究通过控制棕榈蜡(CW)的浓度、均质速度及均质时间制备出粒径较小,分散均匀的棕榈蜡乳液,经3-氨基苯硼酸(ABBA)改性后得到表面接枝有苯硼酸官能团的乳液颗粒(CW-ABBA),之后以CW-ABBA和聚乙烯醇(PVA)为组装单元,在纤维素膜表面组装上一对PVA/CW-ABBA的高分子膜。复合膜的比表面能低,成膜性好,与纤维素的结合力较强,有效的改善了纤维素膜的水蒸气阻隔、拒水及机械性能。结果表明,PVA与CW-ABBA的组装过程具有pH可控性,最佳组装pH值为10.5,在该条件下进行PVA/CW-ABBA组装处理后的纤维素膜的水蒸气透过率下降了24.2%,拒水性能提高了60.2%,抗张指数提高了61.9%,伸长率提高了0.4倍,而且基本保持了原纤维素膜的热稳定性。3.Chitosan-PBA/PVA、PVAm-PBA/PVA多层组装薄膜的制备通过酰胺化反应将4-羧基苯硼酸(PBA)接枝到壳聚糖(Chitosan)和聚乙烯胺(PVAm)的主链上,得到Chitosan-PBA和PVAm-PBA,接着将它们和聚乙烯醇(PVA)作为组装单元,在纤维素膜上进行层层自组装,得到Chitosan-PBA/PVA、PVAm-PBA/PVA多层组装薄膜改性的纤维素膜,同时,以硅片和聚乙烯微球为模型物探讨了高分子对的组装过程。利用椭圆光偏振仪对组装过程中的膜层厚度变化进行了表征;通过电位分析仪对组装过程中微球表面的电荷变化情况进行了测试;利用光学轮廓仪对高分子膜层的均匀性和表面粗糙度进行了追踪;通过抗张试验机对改性纤维素膜的机械性能进行了测试;最后探索了改性纤维素膜对表面含有多醇结构的微球吸附与解吸附性能。结果表明:pH对Chitosan-PBA、PVAm-PBA与PVA之间的相互作用具有影响,在pH 4.5下,聚合物的膜层厚度不随着沉积次数的增加而变化;在pH 5.5-10.5范围内,高分子组装薄膜厚度随着组装溶液pH的升高呈现先增加后趋于稳定的趋势;在相同pH下,Chitosan-PBA/PVA组装对的单层薄膜厚度高于PVAm-PBA/PVA。微球表面的电泳变化显示Chitosan-PBA、PVAm-PBA与PVA组装过程中的电势随着组装次数的增加呈现有规律的多边形线性变化,且Chitosan-PBA/PVA组装对的电势变化幅度高于PVAm-PBA/PVA组装对;光学轮廓仪测试表明,不同pH下组装有相同高分子对数的硅板表面的粗糙度随着pH值的增加而逐步增加,而且相对而言PVAm-PBA/PVA组装对的平滑度更高;机械性能测试表明Chitosan-PBA/PVA和PVAm-PBA/PVA对纤维素膜的机械性能的提高具有积极的作用,其中,PVAm-PBA/PVA的增强效果优于Chitosan-PBA/PVA并且在pH 9.5下具有最佳的增强效果。当纤维素膜表面组装上30对PVAm-PBA/PVA时,纤维素膜的抗张指数和伸长率分别提高了53%和76%。扫描电子显微镜表明改性纤维素膜对含有多醇结构微球的吸附与解吸过程具有pH可控性。此外,热重分析表明PVAm-PBA/PVA改性的纤维素膜的热稳定略好于Chitosan-PBA/PVA改性的纤维素膜。
[Abstract]:Boric acid functional group compounds have attracted wide attention since they were found to be able to form reversible borate esters with 1,2- or 1,3- diols. Especially, the study of composite materials containing benzyl boric acid functional group compounds, that is, the excellent properties of benzyl boric acid are combined with other materials to give new materials. In this paper, the self assembly of the boric acid polyol interaction is used as the driving force. The main research contents are as follows. The three part consists of the preparation, characterization and performance analysis of 1. boracic acid modified cellulose membrane. The 2,2,6,6- four methyl piperidine -1- oxygen (TEMPO) oxidation and amidation were used to graft the benzboric acid functional groups on the surface of the cellulose membrane. The modified fibrin membrane was characterized by infrared spectroscopy and fluorescence; the tensile test machine and the resistance to rupture were used. The mechanical properties of the modified cellulose membrane were tested by the degree meter. At last, the adsorption and desorption properties of the modified cellulose membrane on the surface containing polyol structure were explored. The results showed that the mechanical properties of TEMPO, NaBr and 10 wt% NaClO solutions were 0.05 g, 0.025 g, 4 mL and 45 min, and the mechanical properties were better. The modified cellulose membrane has pH controllability for the adsorption and desorption process of polyol structure microspheres, and the self-assembly of.2. boric acid modified palm wax microspheres on the cellulose membrane by controlling the concentration of the palm wax (CW) by controlling the concentration of the palm wax (CW), the homogenization time and the homogenization time for the preparation of the palm wax emulsion with small particle size and uniform dispersion, through 3- ammonia After modification of benzboric acid (ABBA), the surface grafting of the emulsion particles (CW-ABBA) with benzboric acid functional group was obtained, and then a pair of PVA/CW-ABBA polymer membrane was assembled on the surface of cellulose membrane with CW-ABBA and polyvinyl alcohol (PVA) as assembly unit. The composite film has a lower surface energy, better film forming, stronger binding force with cellulose, and effective improvement of fiber. The water vapor barrier, water repellency and mechanical properties of the vitamin film show that the assembly process of PVA and CW-ABBA has pH controllability and the optimum assembly pH value is 10.5. The water vapor transmission rate of the cellulose membrane after PVA/CW-ABBA assembly treatment under this condition is 24.2%, the water repellent performance is increased by 60.2%, the tensile index is increased by 61.9%, and the elongation rate is raised. It was 0.4 times higher and basically maintained the thermal stability of the original cellulose membrane.3.Chitosan-PBA/PVA, and the preparation of PVAm-PBA/PVA multilayer assembly films by amidation of 4- carboxylic benzyl boric acid (PBA) onto the main chain of chitosan (Chitosan) and polyvinyl amine (PVAm), obtained Chitosan-PBA and PVAm-PBA, followed by them and polyvinyl alcohol (PVA). For the assembly unit, the layers of cellulose films are self assembled on the cellulose membrane to obtain the modified cellulose films of Chitosan-PBA/PVA and PVAm-PBA/PVA multilayer assembly films. At the same time, the assembly process of the polymer pairs is discussed with silicon and polyethylene microspheres as models. The change of the thickness of the film layer in the process of the assembly process is characterized by the elliptical polarizer; The charge change of the surface of the microspheres during the assembly process was tested by the potential analyzer, the uniformity and the surface roughness of the polymer film were traced by the optical profilometer, and the mechanical properties of the modified cellulose membrane were tested by the tensile test machine. Finally, the surface of the modified cellulose membrane was found to contain polyol knots on the surface. The results show that pH has an effect on the interaction between Chitosan-PBA, PVAm-PBA and PVA. At pH 4.5, the film thickness of the polymer does not change with the increase of the deposition times. In the range of pH 5.5-10.5, the thickness of the polymer film is increased with the increase of the pH in the assembly solution, and then tends to increase. The trend of stability is that under the same pH, the electrophoretic change of the layer thickness of the Chitosan-PBA/PVA assembled monolayer is higher than that of the PVAm-PBA/PVA. microsphere, and the potential of the electromotive force in the assembly process of PVAm-PBA and PVA exhibits a regular polygon linear change with the increase of the number of assembly, and the potential of the potential of the Chitosan-PBA/PVA assembly is high. The optical profilometer test shows that the roughness of the surface of the silicon plate with the same polymer logarithm under different pH increases with the increase of pH value, and the smoothness of the PVAm-PBA/PVA assembly pair is higher relatively; the mechanical properties test shows the mechanical properties of Chitosan-PBA/PVA and PVAm-PBA/PVA on the cellulose membrane. The enhancement of energy has a positive effect. Among them, the enhancement effect of PVAm-PBA/PVA is better than that of Chitosan-PBA/PVA and has the best enhancement effect under pH 9.5. When the surface of the cellulose membrane is assembled with 30 pairs of PVAm-PBA/PVA, the tensile index and elongation of the cellulose membrane are increased by 53% and 76 respectively. The adsorption and desorption process with polyol structure microspheres has pH controllability. In addition, TG analysis shows that the thermal stability of PVAm-PBA/PVA modified cellulose membrane is better than that of Chitosan-PBA/PVA modified cellulose membrane.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O636.11

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