论文部分内容阅读
分析四氟乙烯与全氟[3,6-二氧杂4-甲基-△~7辛基磺酰氟]共聚物(简称QF-1)的组成,一般是先将此共聚物在氢氧化钠中水解,使磺酰氟基团变为磺酸钠,然后用盐酸转型为磺酸,再用氯化钠溶液进行交换,用标准碱溶液滴定。这个方法是按离子交换膜测定交换容量(IEC)的方法求得聚合物的当量值,从而得知其组成,但步骤较多。为了减少滴定的误差,聚合物用量也较多,一般需在0.5克以上。考虑到QFeel中除磺酞氟以外的氟原子对碱均很稳定。在水解时只发生下列反应.R,一50:F+ZNaOH一)一一今R,一50必Na+NaF+H:O因而氟离子和磺酸基是等当量的.测定该聚合物碱水解液中的氟离子量,即可知交换当量.粉状树脂不需加工成膜,即可作为试样进行测定,操作简便。又由于氟离子选择电极灵敏度很高,
The composition of tetrafluoroethylene and perfluoro [3,6-dioxa-4-methyl-Δ-7 octylsulfonyl fluoride] copolymer (abbreviated as QF-1) was analyzed. Generally, Sodium hydrolysis, the sulfonyl fluoride group into sodium sulfonate, and then hydrochloric acid into sulfonic acid, sodium chloride solution exchange, titration with standard alkaline solution. This method is based on ion exchange membrane Determination of Exchange Capacity (IEC) method to obtain the equivalent value of the polymer, to understand the composition, but more steps. In order to reduce the titration error, the amount of polymer is also more, generally need more than 0.5 grams. Taking into account the QFeel in addition to the sulfonated fluorine fluorine atoms are very stable to alkali. The following reaction occurred during hydrolysis: R, a 50: F + ZNaOH a) one by one R, a 50 will Na + NaF + H: O and fluoride ions and sulfonic acid groups are equivalent. The amount of fluoride ions in the hydrolyzate can be exchanged equivalent, powdery resin can be measured as a sample without being processed into a film, and the operation is easy. Since fluoride ion selective electrode has high sensitivity,