聚乙烯醇脱水—氧化脱氢制备线型碳

Synthesis of linear carbon by oxidative-dehydration and dehydrogenation of PVA

报道了以聚乙烯醇(PVA)为起始物制备线型碳的研究结果。制备过程类似于炭纤维制备过程中的预氧化工艺,在氧和惰性气体比例适当的条件下,聚乙烯醇在反应釜中梯度升温,以便逐步脱水、氧化脱氢,并保持其原来的晶型。研究了聚乙烯醇在加压下脱水、氧化脱氢制备线型碳的反应条件。产品用红外光谱、激光拉曼光谱和X 射线衍射表征,并与已报道的结果比较,表明产品为β型(累积双键型)线型碳。产品的X 射线衍射结果与原料聚乙烯醇几乎一样,证明产品保持了原料的晶体构型。本合成法可能成为适用的线型碳合成的新途径,并提出了一个可能的反应机理。

A novel linear carbon ( carbyne) was prepared by temperature - programmed dehydration of a crystalline polyvinylalcohol ( PVA) in a stove, followed by dehydrogenation with a suitable ratio of oxygen to inert gas in an autoclave. The linear carbon was characterized by FITIR, Raman and XRD and a possible mechanism for the preparation was proposed. Results show that with a suitable ratio of oxygen to inert gas and temperature profiles for dehydration and dehydrogenation, crystallinity of PVA is retained in the whole process and the linear carbon as prepared is polycumulene, a,beta-linear carbon.