Study On The Synthesis And Properties Of The Polycarboxyli Cement Water-reducing Agent

Polycarboxylic water-reducing agent was synthesized using methyl acrylate, methylacrylamide sodium, methacrylate and polyethylene glycol monomethyl ether methyl- acrylate. Ammonium persulfate as the initiator was used for the radical aqueous solution polymerization. The formulation of the water-reducing agent(APS,0.9%(w/w); n(P23MM) :n(SMS):n(MA) :n(MMA) =20:18:15:47) and optimized reaction conditions (80 oC, 8h)were obtained via orthogonal test and single factor experiments. The initial fluidity of the cement paste containing the prepared water-reducing agent (0.6%, w (water)/w (cement) = 0.3) was 253 mm and remained 248 mm in 2 h. The surface tension of the product solution (1%, w/w) is 53.88 mN/m. The water-reducing agent produced on optimality conditions is pseudo plastic.The reformulation of polycarboxylic water-reducing agent with calcium lignosulfonate (1st generation), JM-9 (2nd generation),and various surfactants was carried out.The cement fluidity with or without additives was measured. The cement has good fluidity by adding 5 %(w/w) peregal-15 and peregal-20, and the fluidity value decreased from 5% to 20% in 2 h.The fluidity ratio increased to 1.3 at 1.5 h by adding 10 %(w/w)Tween-80.When add TX-10,the synergistic effect was a positive correlation,and add 5 % the fluidity ratio was 1.3 at 2h. The fluidity ratio was 1.1 at 1.5 h when 10 %(w/w) benzalkonium bromide was added. Also, the addition of SDS and JM-9 resulted in the decrease of the fluidity ratio in 2 h.The polycarboxylic water reducer was synthesized by free radical polymerization in the presence of initiator 0.9% APS(w/w) with P23MM,SMS,MA,MAA(n(P23MM):n(SMS): n(MA):n(MAA)=20:18:15:47) as monomer using single model microwave radiation technology at 80 oC, 40 min. The properties of the polycarboxylic water reducers obtained from conventional and microwave heating have no obvious difference.