【作者】 陈建芳；

【导师】 王霞瑜； 张海良；

【作者基本信息】 湘潭大学 ， 高分子化学与物理， 2005， 博士

【摘要】 本文简述了星形聚合物、星形杂臂聚合物及树形聚合物三类特殊结构的非线形聚合物的研究进展，同时也介绍了高分子液晶的研究现状，并将非线形结构与高分子液晶结合到同一体系，设计并成功地合成了几类特殊结构的非线形高分子液晶。 设计并用原子转移自由基聚合反应成功地合成了新型的AB₂型星形杂臂甲壳型液晶高分子[PS（PMPCS）₂]和星形杂臂偶氮侧链液晶高分子[PS（PMMAZO）₂]。用差热分析（DSC）、偏光显微镜（POM）及X光衍射（WAXD）研究了以上星形杂臂甲壳型液晶和星形杂臂偶氮侧链液晶共聚物的液晶性，并与相应液晶均聚物和嵌段共聚物的液晶性进行了比较，发现星形杂臂偶氮侧链液晶共聚物的液晶稳定性有所提高，但其近晶相织构受到限制，而星形杂臂甲壳型液晶的液晶行为则基本类似相应液晶均聚物，只有数均分子量大于某一数值时才表现出液晶性。其液晶性与分子量分布及分子形状无关，只与臂的长度有关。 以原子转移自由基偶联法合成了星形聚合物（PEO）_n和星形杂臂（PEO）_n（PS）_n共聚物。以傅立叶红外光谱（FT-IR）、核磁共振（¹H NMR）和GPC分析方法确定了产物的结构。GPC分析结果表明偶联剂的偶联效率高，所得聚合物分子量增大，分子量分布窄。研究了偶联反应的影响因素，发现采用邻二甲苯为溶剂，二乙烯基苯（DVB）为偶联剂，CuBr／bpy为催化剂，在反应温度为110℃，PEO-Br大分子引发剂浓度为0.072M，[DVB]／[预聚物]原料配比为12的反应条件下，偶联反应效率可达99％以上，所得聚合物分子量分布在1.2以下。采用DSC和偏光显微镜POM分析方法研究了星形（PEO）_n聚合物和星形杂臂（PEO）_n（PS）_n共聚物的结晶行为，并与相应线形均聚物及嵌段共聚物的结晶行为进行了比较。发现星形（PEO）_n相对线形PEO均聚物，其结晶能力有所下降且随PEO臂数增加，其熔点和每克PEO的熔融热熔值均下降，其熔体非等温结晶的速度也明显下降。星形杂臂共聚物（PEO）_n（PS）_n和嵌段共聚物PEO-b-PS的熔点和每克PEO的熔融热熔值随共聚物中PS的含量的增加而下降，其熔体非等温结晶的速度也明显下降。星形杂臂共聚物（PEO）_n（PS）_n相对线形嵌段共聚物PEO-b-PS其结晶受限程度增大。 以发散法合成了1.0～4.0代（G）树枝状高分子聚酰胺-胺（PAMAM）及树枝状PAMAM-MMAZO高分子偶氮侧链液晶，讨论了树枝状1.0G PAMAM的合成和更多还原

【Abstract】 This dissertation highlights the development of star polymer, miktoarm star copolymer and dendritic polymer with unique structures. The research status of liquid crystalline polymers （LCP） is reviewed as well. By combining the nonlinear polymer with liquid crystalline polymer, several nonlinear liquid crystalline polymers with special structure have been designed and successfully synthesized.Novel miktoarm star copolymer of AB2, such as PS（PMPCS）2 and PS（PMMAZO）₂, were successfully prepared by by atom transfer radical polymerization （ATRP）. The liquid-crystalline behavior of PS（PMPCS）₂ and PS（PMMAZO）₂ were studied using differential scanning calorimetry （DSC）, polarized optical microscope （POM） and wide angle X-ray diffraction （WAXD）. Compared to the related liquid crystalline homopolymer and block copolymer, we find out that thermal stability of the mesophases of PS（PMMAZO）₂ increased, while the smectic order of PS（PMMAZO）₂ was limited. However, the liquid crystailline behavior of PS（PMPCS）2 is similar to the related liquid crystalline homopolymer. Only when the M_n beyond a certain value, it presents the liquid crystalline, which is related to the length of the arm not the distribute of molecular weight or the shape of the molecular.（PEO）_n star polymer and （PEO）_n（PS）_n miktoarm star copolymer were prepared by ATRP. Their structures were characterized by FT-IR and ¹H NMR. The GPC trace of （PEO）_n（PS）_n miktoarm star copolymer indicate the high efficency of coupling agent, high molecular weight of the so-prepared star polymer with low molecular weight distribution. Several factors play important roles during the star polymer formation. The apt condition is as follows: O-xylene as the solvent; divinylbenzene（DVB） as the coupling reagent; CuBr/bpy as the catalyst. And the temperature is 110°C, PEO-Br （0.072M） as the macroinitiator. The feed ratio of DVB to PEO macroinitiator is 12: 1. The results showed that efficiency of coupling agent was higher than 99 %, with narrow molecular weight distribution less than 1.2.The crystalline behaviors of （PEO）_n star polymer, （PEO）_n（PS）_n miktoarm star copolymer and their related linear polymers were studied using DSC and POM . A更多还原