立體規則性聚(3-己基噻吩)之擴散限制聚合機制研究

Studies on the diffusion-limited mechanism of conjugated regioregular poly(3-hexylthiophene)s

游守智(Shou-Jr You)

指導教授 ： 廖建勛

元智大學/工程學院/化學工程與材料科學學系/碩士(2007年)

https://doi.org/10.6838/YZU.2007.00280

摘要

本實驗使用鎳觸媒格林那試劑耦合法(GRIM)聚合立體規則性聚3-己基噻吩。推測反應後期為擴散限制是造成此反應為準活性的最主要原因。利用質量守衡為原則去推導反應後期的動力式，當Mn大於10,000時，可證明此階段為擴散限制的反應機制。利用階段升溫可有效的提升轉化率與分子量，使分子量最高者由Mw=16,464，PDI=2提升至Mw=17,550，PDI=1.35，且不影響立體規則性。使用高沸點溶劑氯苯，可使迴流溫度提升至氯苯的沸點132℃，其分子量最高的萃取樣品可達Mw=27,299，PDI=1.53。混合溶劑經由UV-vis圖譜分析，確實能使高分子更加膨潤，但因高分子增殖端不溶於溶劑，所以高分子增殖端反而埋藏至高分子團更深處，使反應更加緩慢。由XRD分析可知，分子量較高者之層狀結構皆垂直於基材，而分子量較低者因為分子鏈較短，所以層狀結構出現垂直或平行於基板。層狀結構之距離隨分子量增加而增加，因為分子鏈較長者自組裝不易，所以才會造成晶格距稍大。由FE-SEM分析可知，分子量較高者有條狀自組裝之結構，其條狀結構之寬約等於高分子鏈之長度，表示高分子之排列還未出現繞曲或重疊的情況。分子量較低者有顆粒狀之結構，而未出現一般文獻中的線狀結構，是因為熱處理之溫度過高，造成聚集的現象發生，其顆粒大小約等於分子鏈之長，其結果與XRD分析相符合。

關鍵字

聚(3-己基噻吩) ； 擴散限制 ； 鎳觸媒格林那試劑耦合法

並列摘要

The conjugated regioregular poly(3-hexylthiophene)s (P3HT) was prepared by nickel-catalyzed Grignard metathesis coupling method(GRIM). The later stage of reaction was proposed as diffusion-limited mechanism leading to quasi-living polymerization. Using the kinetic equation by principle of mass balance, the reaction in later stage can be described as a diffusion-limited step. Using temperature programmed polymerization can improve conversion and molecular weight, where the high molecular weight extraction Mw =16,464 PDI =2 has been improved to Mw =17,550 PDI =1.35, with the similar regioregularity. Using the high boiling point chlorobenzene as solvent increases reflux temperature to 132 ℃, the high molecular weight extraction with Mw =27,299 and PDI =1.53 can be obtained. By use of UV-vis analysis, though the mixed solvent swells the polymer, but the propagation ends of polymer do not dissolve in the solvent. It results in the encapsulation of propagation ends of polymer in the deeper region of polymer gel that hinders the further polymerization. From XRD analysis, the layer structure of the high molecular weight extraction is perpendicular to the substrate and the relatively shorter chain of the low molecular weight extraction crystallizes into perpendicular or parallel to the substrate. The increases of distance of the layer structure with molecular weight attributes to that the longer polymer chain self assemble difficultly. From FE-SEM analysis, the high molecular weight extraction of rr-P3HT has a self assembly chain structure, with width approximate to the polymer chain length. It reveals that the polymer stacks without chain folding or overlapping. The lower molecular weight extraction has a particulate structure, different from the usual chain structure. It is due to the high annealing temperature leading to the chain aggregation. The particle size with the same order of magnitude of the polymer chain length is consistent with the XRD results.

並列關鍵字

poly(3-hexylthiophene)s ； diffusion-limited mechanism ； GRIM

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