Synthesis and characterization of thermally stable aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles containing pendant substituted bezamides.
Synthesis and characterization of thermally stable aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles containing pendant substituted bezamides.
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DOI：
10.1186/1752-153x-7-13
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发表时间：
2013-01-23
影响因子：
--
通讯作者：
Mansour el-SM
中科院分区：
文献类型：
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作者：
Hassan HH;Elhusseiny AF;Elkony YM;Mansour el-SM
沿着聚合物主链引入的侧基导致聚合物基质的无序性，并在不影响热性能的情况下增加了溶解性特征。在链中加入显色化学部分可以产生发光转换材料，这使得制备具有潜在应用的材料成为可能。主链上含有杂环的芳香族聚合物具有高耐热性、良好的水解性、低介电性和韧性机械性能。目前，许多研究都致力于发现具有高效率和高可靠性的新型蓝色发光聚合物。在这里，我们描述了芳香族聚酰胺和聚(1，3，4-恶二唑酰胺)S纳米颗粒的制备，这些纳米颗粒具有由间和对乙酰氧基苯甲酰胺基团组成的悬垂结构，其中乙酰氧基苯甲酰胺基团由于其荧光和显色特性而作为信号单元。合成了具有间、对乙酰氧基苯甲酰胺侧链结构的芳香族聚酰胺和聚(1，3，4-恶二唑酰胺)S纳米粒子，并用不同的分析方法对其进行了表征。大多数聚酰胺都是分散良好的球形纳米粒子，而含有吡啶的芳胺通过分子前驱体的氢键定向组织产生了分子自组装的聚集粒子。由于侧链上乙酰氧基的断裂和主酰胺键的断裂，所有聚合物的热行为都表现出两个主要的热分解。光致发光研究表明，与含有柔性键的聚酰胺相比，联苯胺衍生的聚酰胺的蓝光发射发生了蓝移(向更低的波长移动)。报道了由间、对乙酰氧基苯甲酰胺组成的侧链结构的芳香族聚酰胺和聚(1，3，4-恶二唑酰胺)S纳米粒子的合成。由于侧链上乙酰氧基的断裂和主酰胺键的断裂，所有聚合物的热行为都表现出两个主要的分解。结构-光致发光关联显示了结构修饰和光学性质之间有趣的联系。由联苯胺衍生的聚酰胺的蓝光发射归因于高度共轭体系，随着柔性键的引入而蓝移。所制备的聚合物溶解在温极性非质子溶剂中。进一步的研究正在进行中，以获得适用于不同应用的具有相当好的机械性能的薄膜。
The introduction of pendent bulky groups along the polymer backbone results in a less ordered polymer matrix and increases the solubility characteristics without affecting thermal properties. The inclusion of chromogenic chemical moieties in the chains can give rise to the luminescent converter material which permits the preparation of materials with potential applications. Aromatic polymers containing heterocyclic rings in the main chain are known for their high thermal resistance, good hydrolytic stability, low dielectric and tough mechanical properties. There is currently much research directed towards the discovery of new blue light-emitting polymers, with characteristics of high efficiency and high reliability. Herein, we describe the preparation of aromatic polyamides and poly (1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups, where the acetoxybenzamide groups act as signaling units due to their fluorescent and chromogenic characteristics. Aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups were successfully prepared and characterized using different analytical methods. Most polyamides were obtained as well-separated spherical nanoparticles while aramide containing pyridine produced aggregated particles attributed to the molecular self assembly via H-bond directed organization of molecular precursors. The thermal behavior of all polymers exhibited two major thermal decompositions due to the subsequent breakage of the acetoxy group in the lateral chain and cleavage of the main amide bonds. Photoluminescence studies revealed that the blue emissions for the polyamide derived from benzidine were blue-shifted (shifted to a lower wavelength) compared to that of polyamides containing flexible linkages. We report the synthesis of aromatic polyamides and poly(1,3,4-oxadiazole-amide)s nanoparticles with pendant structures comprised of m- and p-acetoxybenzamide groups. The thermal behavior of all polymers exhibited two major decompositions due to breakage of the acetoxy group in the lateral chain and cleavage of the main amide bonds. Structure- photoluminescence correlation demonstrated an interesting connection between structural modification and optical properties. The blue emissions for the polyamide derived from benzidine, attributed to the highly conjugation system, was blue shifted with the introduction of flexible linkages. The prepared polymers dissolved in warm polar aprotic solvents. Further investigations to obtain films with reasonably good mechanical properties for different applications are in progress.