Study On Initiator System Of Starch Gratf Acrylamide Polymerization In Aqueous Two-Phase System

Synthesis of water-soluble polymer in aqueous two-phase system is a newpolymerization method. In the dissertation, initiation systems of starch graft acrylamidepolymerization in aqueous two-phase system are investigated.To the characteristic of starch graft acrylamide polymerization in aqueous two-phasesystem, select potassium permanganate as the initiator, it has the characteristics of sub-triggerand can lead to the formation of solid intermediate adsorbed on the starch particles in theprocess. The starch graft acrylamide polymerization in aqueous two-phase of PEG and PVPuse as dispersion medium and KMnO₄/H⁺as initiator are studied. The results show that: usingPEG as dispersion medium, initiation time is10min, n（KMnO₄）: n（AM）=3.0×10^-4:1, n（KMnO₄）: n（H⁺）=1:10, temperature is50℃, reaction time is7h, and the production ofmonomer conversion is98.88%, grafting ratio is144.53%, grafting efficiency is97.81%;using PVP as dispersion medium, the mass of PVP is6%, temperature is35℃, n（KMnO₄）:n（AM）=3.2×10^-4:1, n（KMnO₄）: n（H⁺）=1:10, the reaction time is8h, and the production ofmonomer conversion is96.50%, intrinsic viscosity is498.51mL/g, grafting ratio is128.98%,grafting efficiency is91.59%.To reduce the temperature of starch graft acrylamide polymerization, thelow-temperature initiated polymerization is investigated, by using ammonium persulfate asthe oxidation of components, constitute the oxidation-reduction system with sodium bisulfiteand sodium hydrosulfite which have different reducing power. Using ammoniumpersulfate-sodium bisulfite as initiator, the better conditions are as follows: temperature is30℃, n（ammonium persulfate）: n（AM）=1.2×10^-3:1, n（ammonium persulfate）: n（sodiumbisulfite）=1:2.0, preparatory initiation time is10min, the mass of PEG20000is10%, reactiontime is9h, and the production of monomer conversion is95.39%, grafting ratio is113.03%,grafting efficiency is63.91%; using ammonium persulfate-sodium dithionite as initiator,temperature is25℃, n（ammonium persulfate）: n（AM）=1.2×10^-3:1, n（ammonium persulfate）:n（sodium dithionite）=1:2.0, initiator and acrylamide added at the same time, reaction time is9h, and the production of monomer conversion is92.61%, grafting ratio is94.77%, graftingefficiency is58.43%.