[Study on the function group uniformity of polystyrol sulfonyl chloride resins by infrared spectra]

The reactions of polyvinyl benzene with chlorosulfonic acid were performed under different ratio and reaction time and the results of chloro-sulfonation were detected by infrared spectrometer (380FT-IR). The characteristic peak at 1 601.5 cm(-1) belongs to benzene ring and was selected as the internal standard peak Two characteristic peaks at 1 377.4 and 3 476.8 cm(-1) were selected as reference peaks, and belong to sulfonyl chloride and sulfonic group respectively. According to the Lambert-Beer law, the absorbance at 1 377. 4 and 3 476.8 cm(-1) was detected and compared with absorbance at 1 601.5 cm(-1) respectively. The value of A1 377.4 : A3 476.8 was used to express uniformity of polystyrol sulfonyl chloride resins. The results show that: (a) After 0.5 h, A1 377.4 : A1 60.5 rises quickly with the prolonging of reaction time; and A3 476.8 : A1 601.5 rises too, but descends after 1 h. And the value of A1 377.4 : A3 476.8 rises with the prolonging of reaction time after 1 h. (b) When the ratio of HSOs Cl and PS is less than 1 : 1, A3 476.8 : A1 601.5 rises with the ratio increasing, but when the ratio of HSO3 Cl and PS is more than 1 : 1, A3 476.8 : A1 601.5 descends while A1 377.4 : A1 601.5 appears and increases following the increase in the ratio. As the ratio was 4 : 1, A1 377.4 : A 601.5 and A3 476.8 : A, 601.5 show stabilization. In one step reaction condition, as the ratio of HSO3 Cl and PS is 4 : 1, the reaction can enhance uniformity of PS-SO2 Cl at 60 degrees C for 5 h (the loading of sulfonyl chloride is 4.0 mmol x g(-1)). It was also confirmed that the function group uniformity of polystyrol sulfonyl chloride resins could be determined by infrared spectroscopy conveniently and quickly. Meanwhile, this method could be adopted to determine the function group uniformity practicably and widely.