全氟磺酸、全氟羧酸膜中“晶点”的形成及其性质的研究

用偏光显微镜、扫描显微镜、透射电镜等方法对全氟磺酸和全氟羧酸膜中的“晶点”进行形貌研究发现，所谓“晶点”不存在明显的各向异性差别，羧酸“晶点”表面由一些颗粒状物组成，不耐电子轰击，产生放电现象。而磺酸“晶点”表面较密实，与周围膜有较明显边界，电子轰击时无放电现象，透射电镜的电子衍射图均呈弥散的德拜环。用红外光谱法和差示扫描量热法对两种树脂的热稳定性进行研究发现，“晶点”形成原因是树脂中不稳定羧端基在一定温度条件下缩聚而形成的，这一结论进一步在热裂解红外光谱研究中得到证实

Formation and Behavior of“Crystals”in Polyperfluorosulfacid and Polyperfluorocarboxylic Acid Membrane

The topograph of the“crystals”in polyperfluorosulfacid and polyfluorocarboxylic acid membrane was studied by polarization microscope(PM),scanning electron microscope(SME)and transmission electron microscope(TME)methods.It is found that so called“crystals”are similar in anisotropy.The“crystals”in polyperfluorocarboxylic acid membrane consist of some grains which discharges when electron bombarded.There is compact surface and explicit border around the“crystals”in polyperfluorosulfacid membrane,which do not discharge when electron bombarded.The pattern of electron diffraction by TEM shows dispersed Debye ring.The“crystals”is also studied by FTIR and TG.The experimental result is that it is the unstable end group of the resin that causes the formation of“crystals”,this is proved by thermal fragmentation FTIR.