PAN/MA及PAN/DMI共聚物之合成與熱分析

Thermal Analysis and polymerization in PAN/MA and PAN/DMI copolymers

蘇凌平(Ling-Ping Su)

指導教授 ： 芮祥鵬

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2013年)

摘要

本研究分為兩部分，第一部分為探討新的碳纖維先驅體丙烯腈(AN)/單體二甲酯衣康酸(DMI)共聚物，並與聚丙烯腈均聚物(PAN)及傳統的丙烯腈/丙烯酸甲酯(AN/MA)共聚物來做對照及探討，第二部分則是利用總體聚合法來改善立體規則度(Tacticity)，並與溶液聚合做對照及討論。
第一個部分，在DSC的非恆溫環化曲線中可以觀察到，AN/DMI共聚物的環化起始溫度會比PAN均聚物及AN/MA共聚物來的低。且在恆溫環化曲線中，我們也可以發現到DMI系列共聚物∆H值約為PAN均聚物的3~4倍，約為MA系列共聚物的1.8倍，說明AN/DMI共聚物環化的程度比較高，証實DMI單體的添加在碳纖維前驅物中確實有助於誘發環化反應的效果。
第二部分，在C13-NMR圖譜中，發現由溶液聚合所聚之AN均聚物、AN/MA共聚物與AN/DMI共聚物的全同結構比例分別為25.8%、30.3%、27.3%，而總體聚合所聚之AN均聚物、AN/MA共聚物與AN/DMI物的全同結構比例可以提升至50.0%、51.8%、58.1%，且在DSC恆溫曲線中，發現總體聚合法所聚合出的聚合物，其∆H值比溶液聚合法來的高，說明總體聚合法可以改善立體規則度(Tacticity)，有效提升全同結構的比例，助於碳纖維穩定化過程的環化反應。

關鍵字

立體規則度 ； 聚丙烯腈環化 ； 碳纖維前驅物

並列摘要

This study can be divided into two parts, the first part of the study is the comparation among AN/DMI copolymer,PAN homopolymer and AN/MA copolymer. the second part is the comparation of solution polymerization and solid state polymerization which use the magnesium chloride as a medium.
In the first part,the non-isothermal DSC studies reveal that the onset temperture of cyclization reaction of AN/DMI copolymer is lower than those of PAN and AN/MA copolymer.In the isothermal DSC studies,we can find that the ΔH value of DMI-series copolymer is about 3 to 4 times the PAN and about 1.8 times the MA-series copolymer.This means the cyclized degree of AN/DMI copolymer is relatively higher.It shows that adding DMI to the he precursor of carbon fiber does contribute to the cyclization reaction of the pre-oxidized carbon fiber.
In the second part, the C13-NMR spectra of the solid state polymerization show that the ratio of isotactic structure of PAN, AN/MA copolymer and AN/DMI copolymer were 50.0%,51.8% and 58.1%,respectively.In the isothermal DSC studies, we found that the ΔH of value solid-state polymerization is higher than that of solution polymerization,those studies indicated that solid-state polymerization can effectively enhance isotactic structure result in favorite cyclization reaction of Stabilization process.

並列關鍵字

tacticity ； polyacrylonitrile ； cyclization ； carbon fiber Precursors

參考文獻

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