基于原位接枝季铵盐抗菌材料的制备及其抗菌性能研究

发布时间：2018-05-04 08:57

本文选题：碳纳米管 + 聚丙烯纤维　；参考：《西南交通大学》2017年硕士论文

【摘要】：材料表面极易生长各种有害细菌,不仅容易引起材料污损和生物腐蚀等,其快速和大量繁殖还会对人类的健康和生存环境造成威胁。因此材料表面的抗菌功能修饰逐渐受到越来越广泛的重视。常见的材料抗菌改性技术主要包括表面涂覆抗菌涂层,复合添加抗菌剂以及通过材料表面化学接枝抗菌成分等。虽然表面涂覆和物理共混的制备方法简单,但抗菌剂的释放量会逐渐降低并存在微生物耐抗药性等问题;相比而言,表面化学接枝抗菌剂是获得长效稳定抗菌性能的有效方法。相对于有机小分子和无机抗菌剂,高分子抗菌剂具有更多的活性官能团,且化学稳定性好,可避免残余毒性。因此将高分子抗菌剂通过简单的方法化学接枝到材料表面具有重要意义。本论文主要针对材料表面涂覆和物理添加抗菌成分后抗菌性能不稳定和长效差等问题,以碳纳米管(CNTs)和聚丙烯(PP)纤维作为改性对象,通过原位季铵化和紫外光引发原位自由基聚合两种方法接枝高分子季铵盐,获得抗菌材料的探索性研究。探讨了季铵化前驱体添加量及分子量、聚合反应单体和引发剂的添加量等因素对季铵盐接枝效果和对材料结构的影响,并研究了改性材料的抗菌性能。1.通过在酸化CNTs表面接枝聚乙烯亚胺(PEI),再对PEI进行季铵化制备表面接枝高分子季铵盐的碳纳米管(QPEI@CNTs),并通过溶剂蒸发法制备了QPEI@CNTs/PLA复合膜以考察其分散性。结果表明,季铵基团的引入显著增加了 CNTs对革兰氏阴性菌和革兰氏阳性菌菌株的抗菌活性,并提高了 CNTs在聚乳酸(PLA)中的分散性。当PEI分子量为70000,与碳纳米管的配比为3:1时,其对代表性实验菌株的最小抑菌浓度(MIC)可以分别达到20-50mg/L(大肠杆菌,Ecoli)和50-100mg/L(金黄色葡萄球菌,Saureus)。2.设计小分子季铵盐甲基丙烯酰氧乙基-苄基-二甲基氯化铵(MBDAC)在光活性剂二苯甲酮经紫外光激发下,在PP纤维表面发生原位自由基聚合反应,获得表面接枝高分子季铵盐的改性PP纤维(PMBDAC@PP)。表征结果表明,PMBDAC@PP纤维表面生成了大量活性官能团,使PP纤维表面由疏水性变为亲水性,季铵盐基团赋予PP纤维良好的抗菌性能;12.68%接枝量的PP纤维对Ecoli和S.aureus的抗菌率均达到了99%以上。3.以丙烯酸为单体,通过紫外光引发自由基原位聚合反应在PP纤维表面接枝聚丙烯酸,随后通过酰胺化反应接枝壳聚糖,并通过(2,3环氧丙基)三甲基氯化铵(ETA)开环反应对其季铵化,制备得到表面接枝壳聚糖季铵盐的PP纤维(QCH@PP-AA)。研究发现,QCH@PP-AA纤维相对于表面仅接枝壳聚糖的CH@PP-AA纤维,对E.coli和S.aureus具有更优异的抗菌性能,3.51%接枝改性的PP纤维,其对两种代表性试验菌株的抗菌率可以达到98%以上。
[Abstract]:All kinds of harmful bacteria are easily grown on the surface of the material, which can not only cause material fouling and biological corrosion, but also threaten the health and living environment of human being. Therefore, the antibacterial function modification of the material surface has gradually been paid more and more attention. The common materials for antibacterial modification include surface coating. In addition to the simple preparation method of surface coating and physical blending, the release amount of the antibacterial agent will gradually decrease and the antimicrobial resistance of the microorganisms exist. In comparison, the surfactants graft antibacterial agent is a long-term and stable antibacterial property. Effective methods. Relative to organic small molecules and inorganic antibacterial agents, polymer antibacterial agents have more active functional groups, and have good chemical stability and can avoid residual toxicity. Therefore, it is of great significance to graft polymer antibacterial agents into the surface of materials by simple methods. The antibacterial properties are unstable and the long effect is poor. Using the carbon nanotube (CNTs) and the polypropylene (PP) fiber as the modified objects, two kinds of quaternary ammonium salts are grafted by in situ quaternizing and UV irradiation in situ free radical polymerization. The exploration of the antibacterial materials is obtained. The amount and the molecular weight of the quaternized precursor are discussed. The effect of the grafting effect of quaternary ammonium salt and the effect on the structure of the material of the quaternary ammonium salt, such as the quantity, the polymerization of the monomer and the initiator, and the study of the antibacterial properties of the modified material.1. by grafting polyethyleneimine (PEI) on the surface of the acidified CNTs, and the preparation of the carbon nanotubes (QPEI@CNTs) to prepare the surface graft polymer quaternary ammonium salt by quaternizing of PEI and through the preparation of the modified carbon nanotubes (QPEI@CNTs). QPEI@CNTs/PLA composite membrane was prepared by solvent evaporation to investigate its dispersibility. The results showed that the introduction of quaternary ammonium group significantly increased the antibacterial activity of CNTs to gram-negative and Gram-positive bacteria, and increased the dispersion of CNTs in polylactic acid (PLA). When the molecular weight of PEI was 70000 and the ratio of carbon nanotubes was 3:1, The minimum inhibitory concentration (MIC) of the representative experimental strains (MIC) can be reached to 20-50mg/L (Escherichia coli, Ecoli) and 50-100mg/L (Staphylococcus aureus, Saureus).2. design small molecule quaternary ammonium salt methyl acryroethoxy benzyl two methyl ammonium chloride (MBDAC) on the surface of PP fiber on the surface of PP fiber under the UV excitation of the PHOTOACTIVATOR two benzophenone. In situ free radical polymerization, the modified PP fiber (PMBDAC@PP) on the surface graft polymer quaternary ammonium salt was obtained. The results showed that a large number of active functional groups were formed on the surface of PMBDAC@PP fibers, which made the surface of PP fibers from hydrophobicity to hydrophilic, and the quaternary ammonium group gave PP fiber good antibacterial properties, and the PP fiber of 12.68% grafting amount to Ecoli and S.. The antibacterial rate of aureus reached more than 99%.3. with acrylic acid as a monomer. The graft copolymerization of polyacrylic acid on the surface of PP fiber by UV irradiation was carried out on the surface of PP fiber. Then the chitosan was grafted by amidation, and the surface graft copolymerization was prepared by the (2,3 epoxy propyl) three methyl ammonium chloride (ETA) ring opening reaction. PP fiber (QCH@PP-AA) of sugar quaternary ammonium salt. It is found that the QCH@PP-AA fiber has better antibacterial properties to E.coli and S.aureus than the CH@PP-AA fiber that is only grafted with chitosan on the surface. The antibacterial rate of the 3.51% graft modified PP fibers can reach more than 98% for the two representative test strains.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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