等规聚环己烯碳酸酯的快速扫描热分析研究

摘要较传统材料而言，高分子材料因其价格低廉、易加工成型、综合性能更为优良等特点，其在人们生活正得到越来越广泛的应用，而生物可降解高分子材料更是因为人们对环境保护的重视而受到更多的青睐。本文拟在研究等规聚环己烯碳酸酯 (iPCHC) 的结晶行为和焓松弛过程，帮助人们对这类可结晶的聚碳酸酯材料能有更为深刻的认识，从而更好地研究和利用这种半晶高分子材料。

本文首先采用商业化的快速扫描量热仪- Flash DSC 分别确定了可抑制 iPCHC 降温过程中熔体结晶和升温过程中冷结晶的临界升降温速率；其次测试了 iPCHC 在不同温度下的等温结晶过程（155 ℃ ~ 205 ℃）和焓松弛过程（85 ℃ ~ 100 ℃），得出了 iPCHC 在各相关温度范围内结晶速率以及松弛时间对温度的关系。结果表明，等规聚环己烯碳酸酯的结晶速度随温度升高呈现“倒悬钟”形，在 190 ℃左右结晶速度最快，此时的半结晶时间为 153s；而其焓松弛时间在 85 ℃~100 ℃之间随温度升高而减小，并且在 95 ℃后这种减小趋势变得平缓，说明这种材料在接近玻璃化学转变的温度区域内老化较快。上述研究结果为新型的课结晶的聚碳酸酯材料的加工和应用提供了重要的参考依据。83374

毕业论文关键词：等规聚环己烯碳酸酯；快速扫描量热仪；结晶动力学；焓松弛

Abstract Comparing to traditional materials, polymer appears cheaper, easier to processing and more advantages properties。 And that’s the reason why the polymer materials, especially biodegradable macromolecules has attracted more and more attentions and been used in a expanding areas。 In this thesis, we want to study the crystallization and enthalpy relax behavior of a crystalizable Polycarbonate (isotactic poly (cyclohexene caubonate)s, iPCHC), in aids of people to learn more in details for the researches and applications of this nevol carbon dioxide based biodegradable polymer。

Here, by using a commercial fast-scan chip-calorimeter (Flash DSC), we first determined the critical cooling and heating rate which can forbid melt-crystallization during cooling and cold-crystallization during heating, respectively。 Secondly, we studied the isothermal crystallization kinetics of iPCHC in temperature range from 155 to 205 ℃, as well as and enthalpy relax of iPCHC in temperature under glass transition, respectively。 The results showed that, the curve of half-crystallization time as a function of temperature appears as an “inverted bell”。 And the fastest crystallization occurrs at around 190 ℃, with half-crystallization time 153 s。 Meanwhile, with the increasing of the temperature from 85 to 100 ℃, the enthalpy relax time decreases from 80 to 53 s even though the decreasing rate turns smaller, which means the ageing is faster with the increasing of the temperature。 Well, the job conducted in this thesis may provide useful suggestions for the following researches and application of iPCHC。

Keywords: isotactic poly (cyclohexene caubonate)s; fast-scan chip-calorimeter; crystallization kinetics; enthalpy relax。

第一章绪论 1

1。1 高分子结晶简介 1

1。1。1 高分子长链结构 1

1。1。2 过冷度 2

1。1。3 结晶生长动力学 2

1。2 焓松弛 4

1。3 Flash DSC 的发展与应用 5

1。3。1 Flash DSC 的发展简史等规聚环己烯碳酸酯的快速扫描热分析研究:http://www.youerw.com/huaxue/lunwen_98273.html