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首页> 外文学位 >PART I: EXPLORATORY SYNTHESIS OF NEW FIRE SAFE POLYMERIC MATERIALS. PART II: THERMAL DEGRADATION STUDY OF PHENOLPHTHALEIN POLYCARBONATE.
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PART I: EXPLORATORY SYNTHESIS OF NEW FIRE SAFE POLYMERIC MATERIALS. PART II: THERMAL DEGRADATION STUDY OF PHENOLPHTHALEIN POLYCARBONATE.

机译：第一部分：新型防火安全聚合物材料的探索性合成。第二部分：酚酞聚碳酸酯的热降解研究。

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Part I. Flammability of polymers is characteristic of a number of factors, such as polymer composition and polymer structure, bond strength, char yield, nature of pyrolysis products, exposure environment, etc. In order to assess the flammability of polymers, 44 polymers based on phenolphthalein and related compounds are prepared and evaluated. The reasons for selecting such polymers are based on the particular nature of their aromatic rings which appears to result in high char formation.; The accumulated data indicate much improved fire resistance for all phenolphthalein related polycarbonates and polyesters, compared with commercial bisphenol-A polymers and emphasizes the importance of polymer composition and polymer structure in affecting the flammability of a polymer. Polycarbonates and polyamides usually show higher oxygen indices than the corresponding polyesters of the related structures. This indicates that the nature of the pyrolysis products has a measurable effect on the flammability of a specific polymer. Among many factors, polycarbonates should release more CO(,2) from the break-down of the carbonate group, and polyamides should produce relatively nonflammable nitrogen-containing products, thus accounting in part, for these results.; Analysis of the phenolphthalein and bisphenol-A copolycarbonates reveals a linear correlation between oxygen index (OI) and char yield (Y): OI = 0.34Y + 19.6 which can be compared with the empirical equation: OI = 0.4Y + 17.5 proposed by D. W. Van Krevelen for other polymers. Analysis also suggests that no chemical interaction occurs between the two comonomers during pyrolysis leading to neither enhanced char yield nor enhanced oxygen index. Study of 4,5,6,7-tetrabromophenolphthalein and phenolphthalein copolycarbonates shows that some enhancement of char yield does occur and that the lower the char yield, the higher is the oxygen index indicating the predominence of a vapor phase bromine effect over that related to char. Study of 4,5,6,7-tetrabromophenolphthalein and bisphenol-A copolycarbonates is interpreted on the basis of two factors--that is, the char effect which predominates over the vapor phase radical scavenging effect at lower bromine content, while at higher bromine content the reverse order is observed.; Part II. Phenolphthalein polycarbonate undergoes random scission and crosslinking during thermal degradation. Kinetic parameters are determined from the dynamic TGA thermograms. During the early stages of degradation, the measured reaction order is nearly 1, suggesting a random chain scission mechanism. The measured activation energy is 42.6 kcal/mole, compared with 41.2 kcal/mole obtained from isothermal aging. The Arrhenius pre-exponential constant is found to be 3.09 x 10('11) min('-1). Below 80% weight residue, the plot of % W against 1/T reveals that complicated reactions with different activation energies occur simultaneously, resulting in a final overlap of curves for different heating rates indicative of crosslinking and a lower pre-exponential constant. The reaction order changes and keeps increasing at the latter stages of degradation.; Pyrolysis of this polymer is performed at 350(DEGREES)C under vacuum, followed by GC-MASS spectroscopic identification of products. The pyrolysis products detected are CO(,2), CO, O(,2), H(,2)O, phenol, fluorenone, diphenyl carbonate, xanthone, anthraquinone, 2-hydroxyanthraquinone, 2-benzoxyanthraquinone, phenolphthalein, diphenyl peroxide and phenyl hydroperoxide. Functional group changes are examined with FT-IR in a continuously evacuated system. Lactone, carbonate and aromatic absorptions decrease during degradation. Increasing absorptions at 1739, 1728, 1280-1200 and 1138-1075 cm('-1) are believed to be a result of two different aromatic ester crosslinkages between chains. Based on the experimental evidence, mechanisms of random scission and crosslinking are proposed.
机译：第一部分：聚合物的可燃性是许多因素的特征，例如聚合物的组成和聚合物的结构，粘结强度，炭的收率，热解产物的性质，暴露环境等。为了评估聚合物的可燃性，使用了44种聚合物对酚酞及其相关化合物进行了制备和评价。选择这种聚合物的原因是基于它们的芳环的特殊性质，这似乎会导致高炭形成。累积的数据表明，与市售双酚A聚合物相比，所有酚酞相关的聚碳酸酯和聚酯的耐火性均得到了大大改善，并强调了聚合物组成和聚合物结构在影响聚合物可燃性方面的重要性。聚碳酸酯和聚酰胺通常显示出比相关结构的相应聚酯更高的氧指数。这表明热解产物的性质对特定聚合物的可燃性具有可测量的影响。在许多因素中，聚碳酸酯应从碳酸酯基团的分解中释放出更多的CO（，2），而聚酰胺应产生相对不易燃的含氮产品，因此部分解释了这些结果。对酚酞和双酚A共聚碳酸酯的分析显示，氧指数（OI）与焦炭产率（Y）之间存在线性关系：OI = 0.34Y + 19.6，可以与经验公式进行比较：DW提出的OI = 0.4Y + 17.5 Van Krevelen用于其他聚合物。分析还表明，在热解过程中，两种共聚单体之间不会发生化学相互作用，从而不会导致炭含量的增加或氧指数的增加。对4,5,6,7-四溴酚酞和酚酞共聚碳酸酯的研究表明，确实出现了焦炭产率的某些提高，并且焦炭产率越低，氧指数越高，表明气相溴作用比与溴化物作用有关的溴作用更大字符基于以下两个因素解释了对4,5,6,7-四溴酚酞和双酚A共聚碳酸酯的研究-即在较低的溴含量和较高的溴含量下，焦炭作用优于气相自由基清除作用满足相反顺序的内容；第二部分酚酞聚碳酸酯在热降解过程中会发生随机断裂和交联。动力学参数由动态TGA热分析图确定。在降解的早期阶段，测得的反应阶数接近1，表明是随机的断链机理。测得的活化能为42.6 kcal / mol，而等温老化得到的活化能为41.2 kcal / mol。发现Arrhenius指数前常数为3.09 x 10（'11）min（'-1）。在残余物重量低于80％时，％W相对于1 / T的曲线表明，具有不同活化能的复杂反应同时发生，导致不同升温速率的曲线最终重叠，表明交联和较低的指数前常数。在降解的后期，反应顺序改变并保持增加。该聚合物在真空（350℃）下热解，然后用GC-MASS光谱法鉴定产物。检测到的热解产物为CO（，2），CO，O（，2），H（，2）O，苯酚，芴酮，碳酸二苯酯，x吨酮，蒽醌，2-羟基蒽醌，2-苯并氧杂蒽醌，酚酞，过氧化二苯和苯基氢过氧化物。在连续排空的系统中，使用FT-IR检查功能组的变化。降解过程中内酯，碳酸盐和芳烃的吸收减少。在1739、1728、1280-1200和1138-1075 cm（'-1）处吸收的增加被认为是链之间两个不同的芳族酯交联的结果。基于实验证据，提出了随机断裂和交联的机理。

著录项

  • 作者

    LIN, MU-SHIH.;

  • 作者单位

    Polytechnic University.;

  • 授予单位 Polytechnic University.;
  • 学科 Chemistry Polymer.
  • 学位 Ph.D.
  • 年度 1980
  • 页码 189 p.
  • 总页数 189
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 高分子化学（高聚物）;
  • 关键词

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