摘要基于DNA与蛋白质螺旋结构的发现,人工合成光学活性的螺旋聚合物开始逐渐发展起来。光学活性螺旋聚合物以其特殊的结构,具有很大的研究应用价值。本文以手性和外消旋酪氨酸为原料,经过酯化反应、缩合反应以及氢转移加成聚合等一系列手段制备了具有光学活性的聚氨酯(OPU)和外消旋的聚氨酯(RPU)。采用凝胶渗透色谱(GPC)、傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H NMR)、圆二色光谱(CD)、紫外-可见吸收(UV-vis)光谱、X射线衍射(XRD)和热失重分析(TGA)等对OPU和 RPU的结构与性能进行了分析与表征。在手性碳原子的诱导作用下,OPU形成了规整的螺旋二级结构,其比旋光度为+65°,而RPU为无规卷曲结构,其比旋光度为0°。OPU出现了螺旋规整结构的结晶峰,大分子体系中存在大量的氢键作用,使其热稳定性得到了一定程度的提高。43301
关键词 光学活性;聚氨酯;氢键;螺旋二级结构
毕业论文设计说明书外文摘要
Title Preparation and performance research on optical active helical polymers
Abstract
Inspired by the helical structure of DNA and protein, the artificial synthesis of optical active helical polymers began to develop gradually. Due to their unique architures, optical active helical polymers are of great value for research and application. In the manuscript, optical activity polyurethane (OPU) and racemic polyurethane (RPU) base on L-tyrosine and DL-tyrosine were prepared by esterification, condensation and hydrogen transfer addition polymerization process. OPU and RPU were characterized through gel permeation chromatography (GPC), Fourier Transform infrared spectroscopy (FTIR), nuclear magnetic reasonance (1H NMR), circular dichroism spectrum (CD), ultraviolet-visible spectrum (UV-vis),x-ray diffraction spectrum (XRD) and thermogravimetic analysis (TGA). Under the inducement of chiral carbon, OPU possessed regular helical secondary structure, the specific rotation of OPU is +65°, whereas RPU was radom coiled with the specific rotation of 0°. The regular crystallization peak appeared in XRD of OPU which contained a great deal of hydrogen bondings, these improved the thermal property of OPU.
Keywords optical activity; polyurethane; hydrogen bond; helical secondary structure
目 次
1 绪 论 1
1.1 引言 1
1.2 光学活性螺旋聚合物的研究历程及现状 2
1.2.1 光学活性螺旋聚合物的研究历程 2
1.2.2 光学活性螺旋聚合物的发展现状 3
1.3 光学活性螺旋聚合物的分类 3
1.3.1 聚烯烃(polyolefin) 4
1.3.2 聚醛(Polychloral) 4
1.3.3 聚硅烷(Polysilanes) 5
1.3.4 聚异氰化物(Polyisocyanides) 5
1.3.5 聚异氰酸酯(Polyisocyanates) 6
1.3.6 聚乙炔衍生物(Polyacetylene Derivatives) 7
1.4 光学活性螺旋聚合物的聚合方法 7
1.4.1 自由基聚合 8
1.4.2 离子引发聚合 8
1.4.3 缩合聚合 8
1.4.4 配位聚合 8