Study On Preparation Of AMPS/AM/AA, AMPS/AM/Humic Acid Sodium Copolymers And Sulfomethylated Phenol Formaldehyde Resin As Filtrating Reducer

Three kinds of heat-resistance filtrate reducers, AMPS/AM/AA copolymer,AMPS/AM/NaHm copolymer and sulfomethylated phenol formaldehyde resin were synthesized.A heat-resistance filtrate reducer was synthesized using 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AM) and acrylic acid (AA) as raw materials and ammonium persulfate/sodium bisulfite as initiators in aqueous solution. The optimum reaction conditions were m(AMPS):m(AM):m(AA)=10:26:4, initiator amount 0.01wt%, pH=4-5 and reaction temperature 40℃. Under above conditions, the intrinsic viscosity of the product is 7.52 dL·g^-1.AMPS/AM/NaHm copolymer was synthesized using 2-acrylamido-2-methylpropane sulfonic acid, acrylamide and sodium humic acid (NaHm) as raw materials and ammonium persulfate/sodium bisulfite as initiators in aqueous solution. Sodium humic acid was prepared from lignite. The obtained reaction conditions were sodium hydroxide amount 2.0wt%, m(sodium hydroxide):m(lignite)=1:5, reaction temperature 100℃and reaction time 3h. The obtained copolymerization conditions were pH=7.0, m(AM):m(AMPS):m(NaHm)=40:20:40, initiator amount 0.5wt% and reaction time 1h at 60℃and then 3h at 80℃. Under above conditions, the viscosity of 1% product solution is 16.26 mPa·s.Preparation of sulfomethylated phenol formaldehyde resin (SMP) was studied by two-step synthetic method. When using sodium bisulfite/sodium sulfite as sulfonating agent, the obtained optimum conditions for preparing sodium hydroxymethanesulfonate were n(sodium bisulfite):n(sodium sulfite):n(formaldehyde)=1:1:2.3,reaction temperature 60℃and reaction time 3h. The obtained optimum conditions for phenolic sulfomethylation were n(sodium hydroxymethanesulfonate):n(phenol)=0.7:1,reaction temperature 90℃,reaction time 1h and pH=9. The obtained optimum polycondensation conditions were n(sodium hydroxymethanesulfonate):n(phenol):n(formaldehyde)=0.7:1:1.4, pH=10, reaction temperature 90℃and reaction time 2h. The drying temperature was 90-100℃. Under above conditions, the yield of SMP was 102.7% with the average viscosity of 6.05 mPa·s (10% aqueous solution). When using sodium metabisulfite as sulfonating agent, the obtained optimum conditions for preparing sodium hydroxymethanesulfonate were n(sodium metabisulfite):n(formaldehyde)=1:2.5,reaction temperature 80℃and reaction time 3h. The obtained optimum conditions for phenolic sulfomethylation were n(sodium hydroxymethanesulfonate):n(phenol)=0.8:1,reaction temperature 85℃,reaction time 2h and pH=10. The obtained optimum polycondensation conditions were n(sodium hydroxymethanesulfonate):n(phenol):n(formaldehyde)=0.8:1:1.5, pH=11, reaction temperature 90℃and reaction time 2h. Under above conditions, the yield of SMP was 99.6% with the average viscosity of 6.17 mPa·s (10% aqueous solution).Preparation of sulfomethylated phenol formaldehyde resin was also studied by one-step synthetic method. When using sodium bisulfite/sodium sulfite as sulfonating agent, the obtained optimum conditions for hydroxymethylation were n(sodium bisulfite):n(sodium sulfite):n(formaldehyde)=1:1:2.2,reaction temperature 60℃and reaction time 3h. The obtained optimum conditions for phenolic sulfomethylation were n(sodium bisulfite):n(sodium sulfite):n(phenol)=1:1:3,reaction temperature 90℃,reaction time 1.5h and pH=8. The obtained optimum polycondensation conditions were n(phenol):n(formaldehyde)=1:1.4, pH=10, reaction temperature 90℃and reaction time 1h. Under above conditions, the yield of SMP was 99.6% with the average viscosity of 6.27 mPa·s (10% aqueous solution). When using sodium metabisulfite as sulfonating agent, the obtained optimum conditions for hydroxymethylation were n(sodium metabisulfite):n(formaldehyde)=1:2.6,reaction temperature 85℃and reaction time 1h. The obtained optimum conditions for phenolic sulfomethylation were n(sodium metabisulfite):n(phenol)=0.4:1,reaction temperature 90℃,reaction time 1.5h and pH=9.5. The obtained optimum polycondensation conditions were n(phenol):n(formaldehyde)=1:1.25, pH=10, reaction temperature 100℃and reaction time 2h. Under above conditions, the yield of SMP was 98.9% with the average viscosity of 6.21 mPa·s (10% aqueous solution).The structures of the above obtained products were characterized by FT-IR, and the filtrating loss performances of the products were evaluated in fresh water based mud in laboratory. The results showed that the products were of better performance of heat-resistance and filtrating loss.