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	磷酸-氨水蒸沉γ晶型聚酰胺6的热行为研究; Investigation of Thermal Behaviors of γ-Form Nylon 6 Prepared by Ammonia Vapor from Phosphoric Acid Solutions
	葛佳文 ; 刘少轩 ; 章成峰 ; 李钦 ; 夏锦明 ; 徐怡庄 ; 吴瑾光
	2012
关键词	尼龙6 γ晶型 蒸沉法 热行为 红外光谱 Nylon 6 gamma form Vapor precipitation Thermal behavior FTIR
英文摘要	尼龙6是一种多晶型的半结晶高聚物.实验采用蒸沉法制备出尼龙6,首先通过XRD和FTIR的手段进行表征,与采用沸水处理的尼龙6样品表征结果对比,确定其为γ晶型,然后在130～211℃的温度范围内进行热处理,通过DSC研究其在低于熔点热处理时的整个热行为变化过程,并运用FTIR观察其在不同条件下热处理发生的晶型变化.发现蒸沉法制备的γ晶型尼龙6随着热处理温度的升高,整体结晶完善度以及晶片厚度随着处理温度的升高而增加.而且在这个过程中,样品厚度不同的晶片在不同温度下发生了γ晶型向α晶型的转化,最终在接近熔点(211℃)热处理时,样品变为以α晶型为主.; In the present work, we prepared nylon 6 crystals via crystallization of nylon from phosphoric acid by using the vapors of ammonium hydroxide as a precipitation regent. Both XRD and FTIR results demonstrate that the obtained nylon 6 sample exhibit characteristic peaks of nylon 6 in gamma form. In addition, treatment of nylon 6 in boiling water for half an hour followed by FTIR and XRD characterization shows that the obtained nylon 6 sample is in gamma form rather than in meta-stable b form. DSC characterization indicates that the nylon 6 sample exhibits two melting peaks (213 and 220 C) when the sample is heated at a heating rate of 10 degrees C . min(-1). The reason for this phenomenon is that the nylon 6 sample has different lamellar thickness. To investigate the thermal behavior of the nylon 6 sample, the sample underwent the following thermal treatment procedure. First, the sample was heated to a pre-set temperature (T-s,) and kept at that temperature for an hour. Subsequently, the sample was cooled down to 100 degrees C at a cooling rate of 1 degrees C . min(-1), and then cooled down to room temperature at a cooling rate of 10 degrees C . min(-1). The treated samples were characterized by FTIR and DSC method. Experimental results show that the treated nylon 6 samples exhibit different crystalline behavior. When T-s, ranges from 130 to 160 degrees C, no significant changes were observed. When T-s is 170 degrees C, a small fraction nylon 6 crystals is destroyed and recrystallized into thin lamellae in a form. As a result, a pre-melting peak appears in DSC result. The pre-melting peak moves to higher temperature and its peak area increases significantly upon increasing T-s from 170 to 198 degrees C. When T-s amounts to 200 degrees C the pre-melting peak and the melting peaks 213 degrees C merge into one melting peak and two melting peaks are observed at 212 and 220 degrees C in the DSC results. FTIR spectra indicate that significant amount of crystalline nylon 6 in a form appears but the majority of crystalline phase of the sample is still 7 phase. As T-s, increases from 200 to 209 degrees C, the melting peak at lower temperature moves to higher temperature with increasing its peak area. On the other hand, the melting peak at 220 degrees C decreases in intensity but does not show any peak shift. As T-s reaches 209 degrees C, the two melting peaks merge into one peak and FTIR results demonstrate that nylon 6 in a form becomes dominate phase in the sample. In the whole heat-treatment process, the gamma phase nylon 6 sample began to transform to alpha phase at the heat-treatment temperature of 170 degrees C, which is far below the melting point of the original sample (221 degrees C). This is different from the results reported in the literature, which state that gamma phase nylon 6 will not transform to alpha-phase until nylon is melt.; 国家自然科学基金项目; 国家(863计划)重大项目; 科技部平台项目; 北京市专利基金; 北京大学先进技术研究院培育项目; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000298900300028&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 1; 1; 118-122; 32
语种	中文
出处	万方 ; SCI ; http://d.g.wanfangdata.com.cn/Periodical_gpxygpfx201201028.aspx
出版者	光谱学与光谱分析
内容类型	其他
源URL	[http://hdl.handle.net/20.500.11897/80006]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	葛佳文,刘少轩,章成峰,等. 磷酸-氨水蒸沉γ晶型聚酰胺6的热行为研究, Investigation of Thermal Behaviors of γ-Form Nylon 6 Prepared by Ammonia Vapor from Phosphoric Acid Solutions. 2012-01-01.

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