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感光性天然高分子膜的制备与性能研究
Preparation and Properties of the Photocrosslinked Natural Macromolecule Membrane
【作者】 赵涛;
【作者基本信息】 江南大学 , 材料学, 2009, 硕士
【摘要】 壳聚糖(CS)是一种可再生天然大分子,可用于环境友好、可降解材料。聚乙烯醇-苯乙烯基吡啶盐缩合物(PVA-SbQ)是一种新型光敏聚合物,在紫外光诱导下,能发生光二聚反应形成大分子网状结构。本文涉及光交联壳聚糖-(PVA-SbQ)共混膜、光交联壳聚糖-(PVA-SbQ)双层复合膜、壳聚糖-SbQ树脂的研究。由以下三部分组成:第一部分通过溶液共混法,在壳聚糖膜中引入具有光二聚特性的PVA-SbQ,成膜后在紫外灯辐照下进行光交联反应,制备了光交联壳聚糖-(PVA-SbQ)共混膜。用扫描电镜、X-射线衍射、傅立叶红外等方法对膜的结构进行表征,并对膜的力学性能、吸湿率、透光率、接触角、水蒸气透过率、溶胀率等性能进行研究。实验结果表明:光交联壳聚糖-(PVA-SbQ)共混膜的表面形态比较独特;壳聚糖与PVA-SbQ分子间存在一定的氢键相互作用;光交联后,共混膜形成网状结构,有效地改善了壳聚糖膜的力学性能、吸湿性和紫外屏蔽性能等。第二部分以壳聚糖、PVA-SbQ为膜材料,通过溶液浇铸法制备了光交联壳聚糖-(PVA-SbQ)双层复合膜。用扫描电镜等对膜结构进行了表征,并对膜的力学性能、吸湿率、透光率、水蒸气透过率、溶胀率等性能进行研究。实验结果表明:壳聚糖-(PVA-SbQ)双层复合膜剖面致密光滑,无孔洞出现,仅出现模糊地界面层;光敏聚合物PVA-SBQ的引入,壳聚糖-(PVA-SbQ)双层复合膜吸湿率降低,水蒸气透过率下降,力学性能下降,而膨胀率有所升高;在可见光范围内,壳聚糖-(PVA-SbQ)双层复合膜有较好透光率(透光率为70%以上),而对400nm以下UV有选择性吸收,紫外光完全不透过,紫外屏蔽性较好,可望在防紫外涂层材料方面得到应用。第三部分采用希夫碱反应将SbQ接枝到壳聚糖颗粒表面,制备了壳聚糖-SbQ树脂。通过傅立叶红外、XRD、表征壳聚糖-SbQ树脂基本结构,研究了壳聚糖接枝SbQ前后对Cu2+、Co2+的吸附性能。结果表明:壳聚糖接枝SbQ反应是成功的,但是接枝率不高;壳聚糖-SbQ树脂改善了其在酸性介质中的稳定性,对金属离子有一定的吸附,在较宽pH范围的都有吸附分离功能,拓展了其应用范围。
【Abstract】 Chitosan(CS)is a kind of natural macromoleculule and chitosan based material are expected to be environment-friendly, biodegradable and reproducible products. Polyvinylacohol (PVA) bearing styrylpyridinium group (PVA-SbQ) is a new photosensitive polymer, styrylpyridinium group on side of PVA main chain can be cross-linked under UV radiation to form network. We focused on Photocrosslinked chitosan-(PVA-SbQ) blend membrane, Photocross-linked chitosan-(PVA-SbQ) two layer composite membrane and chitosan-SbQ resin in this paper.In part 1, Photocross-linked chitosan-(PVA-SbQ) blend membrane was made by mixing the solutions of chitosan and PVA-SbQ. Its structure was examined by means of SEM, XRD and FTIR. The properties of membrane, such as mechanical property, light transmittance, hygroscopicity, surface contact angle, water uptake, degree of swelling had been studied. The results showed that membrane with interesting surface structure, there was some hydrogen bonding interaction between chitosan and PVA-SbQ in the blend membrane, Exposed membrane had network, which improved properties of the membrane such as mechanical property, hygroscopicity and UV screen property.In part 2, Photocross-linked chitosan-(PVA-SbQ) two layer composite membrane was made by the solvent casting method.we use SEM to study its structure, the properties of membrane, such as mechanical property, light transmittance, hygroscopicity, water uptake, degree of swelling had been studied. The results showed that membrane with smooth side-face structure. Exposed membrane had network, which improved the membrane’s properties such as hygroscopicity, water uptake ability, but degree of swelling was falled. In the range of visible light, the light transmittance of membrane exceeded 70%, but when the wavelength less than 400nm, the light transmittance of membrane was 0%, Photocross-linked chitosan-(PVA-SbQ) two layer composite membrane had better UV screen property.In part 3, we synthesized chitosan-SbQ resin by shifft reaction. Its structure was examined by means of XRD and FTIR, and the adsorption propertier of the resin on Cu2+, Co2+ had been studied. The results showed that the reaction was successful, but graft rate was low, Chitosan-SbQ resin improved the stability of chitosan in acid medium, which had better selectivity of absorption on metal ions in wide pH range. chitosan-SbQ resin expanded the application scope of chitosan.
【Key words】 Chitosan; PVA-SbQ; photocross-link; membrane; ion-adsorption;