聚氟氯代羧酸乙烯酯的制备及其立体规整性

氟氯代羧酸与乙炔反应制得氟氯代羧酸乙烯酯,后者分别以过氧化二苯甲酰和三丁基硼为引发剂在不同温度下进行本体聚合。以X-射线衍射图和红外吸收率D_(916)/D_(850)比值观测聚乙烯酯及其水解物聚乙烯醇的立体规整性。不同侧链长度的聚含氟酸乙烯酯的X-射线衍射图并没有反映出高分子链在立体规整性上的差异,但其水解产物聚乙烯醇D_(916)/D_(850)吸收率比值随侧链体积增大而增加、侧基极性效应和空间效应的影响是肯定的。不论是聚乙酸乙烯酯和聚含氟酸乙烯酯聚合温度对它们的立体规整性都没有明显的影响。

STUDIES ON THE PREPARATION AND POLYMERIZATION OF VINYLESTERS OF CHLOROFLUOROCARBOXYLIC ACIDS AND THE STEREOREGULARITY OF FLUORINE-CONTAINING POLYVINYLESTERS

This paper deals with the preparation and polymerization of various fluroine-containing vinylesters under different polymerization temperatures. By measuring the X-ray diffraction pattern of polyvinyl esters and the IR absorbance ratio D916,/D850 of polyvinyl alcohol (PVA) derived from its correspondent polyvinyl esters, no distinct differences in stereoregularity were observed among these polyvinyl esters with different length of polar side groups. But the absorbance ratio D916/D850 increased, i.e. the stereo-regularity of PVA was enhanced with increasing the length of the polar alkyl side groups of its predecessors. The stereo and polar effect are obvious.The temperature dependance of tacticity was studied in the range of - 78 to 60℃ and it was found that with lowering of polymerization temperature, there is little affect on the tacticity of polyvinyl esters. Difference in chain regularity do exist in various fluorine containing polyvinyl esters, these are due to lateral interchain order between ester groups and are not indicative of the configuration of the carbon chains.