Synthesis and interpolymer complexation of a novel polycation with 2-hydroxyl-3-ethoxyprop-1-yl groups, high density of charge and excellent proton buffering capability

When polycation and polyanion with high density of charge are directly mixed at middle component ratios to prepare interpolymer complex, aggregation and sediment are often encountered. In this work, a novel randomly branched polycation, PTEE, with high density of charge and lots of big hydrophilic groups of 2-hydroxyl-3-ethoxyprop-1-yl, was synthesized and its interpolymer complex with PAA was prepared by direct mixing to examine the effect of big hydrophilic groups on complex formation and stability. The structures of PTEE and its precursor and complex were characterized by 1 HNMR and FT-IR. PTEE/PAA complex particle size, size distribution and stability were measured. Results showed that 2-hydroxyl-3-ethoxyprop-1-yl groups obviously improved complex formation and small complex particles were obtained. The largest mean particle size of PTEE/PAA complex was 320 nm, far smaller than the 20,000 nm of the reference polycation without big hydrophylic groups. Results also showed, different from the contribution to complex formation, big hydrophilic groups had no obvious contribution to static standing stability.