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首页> 外文学位 >Synthesis and characterization of arylmethyl sulfone dendrimers and hyperbranched poly(phenylene sulfide)/poly(sulfone).
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Synthesis and characterization of arylmethyl sulfone dendrimers and hyperbranched poly(phenylene sulfide)/poly(sulfone).

机译：芳基甲基砜树枝状大分子和超支化聚苯硫醚/聚砜的合成与表征。

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摘要

In recent years, nonlinear polymers such as dendritic and hyperbranched macromolecules have attracted considerable attention owing to the potential new properties of their highly branched, highly functionalized, three-dimensional globular structures. Chemists have begun to explore controlled ways of making synthetic polymers with highly branched structures, known as dendrimers and hyperbranched polymers. Dendrimers have a well-defined and perfectly branching structure, and are built up by either a stepwise divergent or convergent approach. Hyperbranched polymers are prepared by a one-step polymerization process that yields a highly branched, irregular structure.;A synthetic approach to an arylmethyl sulfone dendrimer was explored based on a convergent synthesis. An A2B monomer with activated A sites and protected B site is required, and 5-sulfo-isophthalic acid sodium salt was used as a starting material. First, two carboxylic acids at the A sites were protected by esterification in methanol/concentrated sulfuric acid, then the sulfonic acid at the B site was protected by making a sulfonate ester via the sulfonyl chloride. Second, two A sites were activated by reducing the esters to benzyl alcohols, then transforming to benzyl chlorides to generate the phenyl 3,5---bis-chloromethyl-benzenesulfonate monomer. Following a common method for synthesis of sulfones, this monomer was reacted with benzenesulfinic acid sodium salt to make a generation I (G1) arylmethyl sulfone dendrimer. The deprotection of the phenylbenzenesulfonate was not successful. Literature methods such as decomposition with hydrazine and reduction all failed.;Hyperbranched poly(phenylene sulfide) was prepared from 3,5-dichlorobenzenethiol by one-pot approach using K2CO3 as base, NMP as solvent, and 150°C for 8 hours. Hyperbranched poly(phenylene sulfone) was generated by oxidization with H2O2 from hyperbranched poly(phenylene sulfide). A core-terminated hyperbranched poly(phenylene sulfide) was prepared by adding 1,3,5-trichlorobenzene as a core under the same conditions. An end-capped hyperbranched poly(phenylene sulfide) was made by adding 2-naphthalenethiol as an end-cap. The polymers were primarily characterized by size exclusion chromatography with light scattering detection (which provided the molecular weights and distributions) and thermal methods such as differential scanning calorimetry/thermogravimetric analysis. Polymerization for 8 hours at 150°C in NMP gave hyperbranched poly(phenylene sulfide) with an Mw of 29 kD and a polydispersity of 1.1; core-terminated hyperbranched poly(phenylene sulfide) with an Mw of 14 kD and a polydispersity of 1.1 and end-capped hyperbranched poly(phenylene-sulfide) an Mw of 18 kD and a polydispersity of 1.2. Hyperbranched poly-(phenylene sulfide), core-terminated hyperbranched poly(phenylene sulfide), end-capped hyperbranched poly(phenylene sulfide) and hyperbranched poly(phenylene sulfone) were amorphous with Tg of 74, 66, 75 and 203°C respectively and no apparent crystallinity by differential scanning calorimetry (DSC). Thermogravimetric analysis(TGA) showed that the materials were very thermally stable, with decomposition temperatures between 375 and 545°C in both air and N2 atmospheres.
机译：近年来，由于其高度支化，高度官能化的三维球状结构的潜在新特性，诸如树枝状和超支化大分子之类的非线性聚合物引起了相当大的关注。化学家已经开始探索受控的方法来制备具有高度支化结构的合成聚合物，称为树枝状聚合物和超支化聚合物。树枝状聚合物具有定义明确的分支结构，并通过逐步发散或收敛的方法构建。超支化聚合物是通过一步聚合反应制备的，该聚合反应可产生高度支化的不规则结构。;基于聚合合成，探索了一种合成芳基甲基砜树枝状聚合物的方法。需要具有活化的A位和受保护的B位的A2B单体，并且使用5-磺基间苯二甲酸钠盐作为起始原料。首先，通过在甲醇/浓硫酸中的酯化作用，保护A位点的两种羧酸，然后通过磺酰氯制备磺酸酯来保护B位点的磺酸。其次，通过将酯还原为苄醇，然后转化为苄基氯，生成苯基3,5--双-氯甲基-苯磺酸酯单体，从而活化两个A位点。按照合成砜的常用方法，使该单体与苯亚磺酸钠盐反应，生成第一代（G1）芳基甲基砜树状聚合物。苯基苯磺酸盐的脱保护不成功。用肼分解和还原等文献方法均告失败。用3,5-二氯苯硫醇通过一锅法以碳酸钾为碱，NMP为溶剂，在150°C下反应8小时制得超支化聚苯硫醚。超支化的聚苯砜是由超支化的聚苯硫醚经H2O2氧化制得的。通过在相同条件下添加1,3,5-三氯苯作为核，制得核端基的超支化聚苯硫醚。通过添加2-萘硫醇作为封端，制得封端的超支化聚苯硫醚。聚合物的主要特征是通过具有光散射检测（提供分子量和分布）的尺寸排阻色谱法以及诸如差示扫描量热法/热重分析的热方法。在NMP中于150°C聚合8小时，得到Mw为29 kD，多分散度为1.1的超支化聚苯硫醚。 Mw为14 kD，分散度为1.1的端基超支化聚苯硫醚，封端的Mw为18 kD的超支化聚苯硫醚，多分散度为1.2。超支化聚苯硫醚，核端基超支化聚苯硫醚，封端的超支化聚苯硫醚和超支化聚苯砜是无定形的，其Tg分别为74、66、75和203℃。通过差示扫描量热法（DSC）没有明显的结晶度。热重分析（TGA）表明，该材料非常热稳定，在空气和N2气氛中的分解温度在375至545°C之间。

著录项

  • 作者

    Zhao, Qiuxia (Lucy).;

  • 作者单位

    Seton Hall University.;

  • 授予单位 Seton Hall University.;
  • 学科 Chemistry Organic.;Chemistry Polymer.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 171 p.
  • 总页数 171
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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