Gamma-irradiation synthesis of quaternary phosphonium cationic starch flocculants Available to Purchase

Quaternary phosphonium cationic starch (St-g-AM/ATPPB) flocculant was synthesized by using corn starch and acrylamide (AM), allyl triphenyl phosphonium bromide binary (ATPPB) through simultaneous gamma-irradiation. The chemical structure of the copolymer was characterized by FTIR (Fourier transform infrared spectroscopy) and ¹H NMR (nuclear magnetic resonance) technologies. The effects of the absorbed dose in the range of 1 to 6 kGy, AM/ATPPB ratio and starch/(AM + ATPPB) ratio on grafting and flocculation were investigated. At a starch:AM:ATPPB wt ratio of 1:1.4:0.93, the graft ratio of AM/ATPPB reached maximum values at 3 and 6 kGy, and the cationic degree of St-g-AM/ATPPB increased with absorbed dose, while the turbidity reduction reached a maximum value at 5 kGy. At 3 kGy using a starch:(AM + ATPPB) wt. ratio of 1:2.33, the graft ratio of AM and ATPPB increased with AM/ATPPB ratio, while the cationic degree and turbidity reduction reached maximum values at AM:ATPPB wt. ratios of 1:0.67 and 1:0.5, respectively. At a constant AM:ATPPB wt. ratio of 1:0.67 and 3 kGy, the grafting ratio increased with starch/(AM + ATPPB), while the cationic degree and turbidity reduction simultaneously reached maximum values at a starch:(AM + ATPPB) wt. ratio of 1:2.67. Further study revealed that the higher the absorbed dose or the lower the starch/(AM + ATPPB) ratio, the lower the optimal flocculant concentration.