【作者】 刘丹；

【导师】 张超灿；

【作者基本信息】 武汉理工大学 ， 材料学， 2004， 硕士

【摘要】 本论文概述聚乙烯亚胺为主链的液晶高分子和聚乙烯亚胺型螯合树脂的研究进展。在分析高分子液晶结构与性能关系的基础上，设计并合成了六种以聚乙烯亚胺(PEI)为主链，亚甲基为间隔基的侧链含介晶基团的聚合物(PN6 Ⅰ、PN4 Ⅰ、PN6 Ⅱ、PN4 Ⅱ、PN6Ⅲ、PN4Ⅲ)。用核磁共振(~1H NMR)、红外光谱(IR)等手段对它们的结构进行了验证。用DSC、偏光显微镜及X射线衍射等研究了这些聚合物的液晶相转变温度及相行为。 本论文分别用4′一甲氧基-4-羟基联苯、4-羟基联苯和五氯苯酚作为介晶基团与PEI进行反应，研究了合成反应的条件，并提出了不同的合成路线。用工R手段区分了六种不同结构的聚合物，用~1H NMR验证结构的同时计算了侧链在N-H键上的取代度。DSC测试结果显示以联苯基衍生物作为介晶基团可以得到双向性液晶，而以五氯苯酚作为介晶基团不能得到具有液晶性的高分子。这四种聚合物从液晶相到各向同性相的相变焓都很大，并且每种液晶型聚合物的相变温区(△T)都较宽，表明这类聚合物具有较高的液晶相稳定性。间隔基的长度对液晶行为亦有较大的影响，随着间隔基长度的增加，液晶相的清亮点温度Ti随之减小。偏光显微镜照片显示PN6Ⅰ是典型的向列相纹影织构，PN4Ⅰ经历了从近晶相的扇形织构到向列相的纹影织构的转变，PN6Ⅱ是向列相条纹织构，PN4Ⅱ是向列相丝状织构。X射线衍射曲线图上四种液晶型聚合物在θ=20°左右都有尖锐的衍射峰，而PN4Ⅰ在2°处还有衍射峰，表明PN4Ⅰ是具有多相液晶态的液晶高分子，表明近晶相的存在。并且根据布拉格公式计算了每种聚合物侧链液晶基元之间的平均距离。 作为一种常用的螯合树脂，PEI存在着易溶于酸，质软，难成形以及易流失等缺点。将侧链上带上刚性基团，使改性的PEI具有一定的硬度和形状，不易流失，克服以上缺点。因此用合成了的六种树脂对Hg(Ⅱ)、Cd(Ⅱ)、Co(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)、Cr(Ⅲ)、Pb(Ⅱ)、Mg(Ⅱ)进行了吸附性能以及选择性吸附的研究。结果表明六种树脂对Hg(Ⅱ)有很好的吸附性能和吸附选择性，对Cd(Ⅱ)、Co(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)、Pb(Ⅱ)这些过渡金属离子也有较好 武汉理_l:人学硕十学位论文的吸附性能，而对Mg(H)的吸附能力就很差。树脂在20℃左右对Cu(ll)的吸附量最大，温度升高或者降低都阻碍了吸附过程的进行。PN6I、PN4I型树脂的吸附速率最大，而PN6II、PN4ll型树脂的吸附速率要小的多。树脂在混合金属离子中优先选择吸附Hg(H)，因此可以用于含Hg(ll)有毒废水的处理。更多还原

【Abstract】 Based on the review of the relationship between chemical structure and properties for polymer liquid crystallines and the recent research progress of liquid crystalline polymer with poly(ethyleneimine) as the main chain, six novel types of polymers with side-chain mesogenic groups and the methylene units as spacer were synthesized. All of the novel polymers(PN6 I , PN4 I , PN6II, PN4 II, PN6III, PN4III) were structurally characterized by !H NMR, IR spectra. The liquid crystalline properties of the polymers prepared were also investigated by differential scanning calorimetry(DSC), polarizing microscopy and X-ray measurement.4-hydroxy-4’ -methoxybiphenyl, 4-hydroxybiphenyl , pentachlorophenol were used in this paper as mesogenic side groups and reacted with poly(ethyleneimine)(PEI), different reaction situation were tried. IR and ’H NMR were used to characterize the different structure, the branching degree of the mesogenic side groups on N-H units of PEI were also calculated from ’H NMR.DSC analyses show that with biphenyl as the mesogenic, the branched PEI shows bitropic phase behavior. While with the side groups of pentachlorophenol, the branched PEI shows no liquid crystalline properties. The heat flow of these polymers from liquid crystalline phase to isotropization is very high. Results also show that these polymers posses wide temperature range of liquid crystalline phase, which implied consequently better thermostability. The spacer influences the mesophase behaviour dramatically. The longer the spacer, the lower of the isotropisation transition temperature(Ti) is. The polarizing microscopy observed from the liquid crystalline indicate that the PN6 I polymer has the schlieren texture , PN4 I polymer overcome the transition from fan texture to schlieren texture, while PN6II is banded texture, PN4II is threaded texture. The four liquid crystalline polymer illustrate peaks at the 2 9 of about 20掳 in the X-raydiffraction and PN4 I illustrate peaks of about 2. which implying the exiting of smectic phase in PN4 I . The space(d) of the the mesogenic side units was also calculated from Bragg’ s equation.PEI is outstanding for both the backbone of liquid crystalline polymer and a widely used chelating resins. PEI as chelating resins is short for its no shape and easy to flow. When PEI was branched with rigid side units, PEI posses hardness and shape, hard to flow. And most important is that a novel kind of liquid crystalline chelating resins was synthesized here. The adsorption properties for Hg(II), Cd(II), Co(II), Cu(II), Cr(III), Zn(II), Pb(II), Mg(II) and their absorptive selectivity, the influence of temperature and time during absorption were studied. Results show that the resins have excellent absorption and absorptive selectivity for Hg( II) and some absorption to Cd( II), Co( II), Cu( II), Zn( II), Pb( II) but poor absorption to Mg( II). The influence of temperature show that 20 掳C is a critical temperature to Cu( II). Higher or lower temperature cumbers the absorption. PN6 I and PN4 I posses a high absorption speed to ions but PN6III and PN4III a lowest absorption speed. In the coexist of Hg(II), Zn( II), Cr(III), Cu( II), Mg( II), the resins could selectively absorb Hg( II), and thus can be used for the waste water purify and protect the environment.更多还原