Study On The Process Optimization Of Sulfonated Acetone-formaldehyde Superplasticizer Incorporating No Heat Source Productive Technology

Aliphatic superplasticizer is a kind of sulfonated acetone-formaldehyde polymer,anew type of anionic surfactant.Its distinguishing feature is the stable raw materialprices,wide variety of sources,high water reducation,better compatibility with a varietyof cement,the better cost performance compared with the traditional naphthalene-basedsuperplasticizer.Aliphaticthe superplasticizer is more widely used by theseadvantages.At present,there are kinds of production technologys of aliphaticsuperplasticizer.According to the needing of external heat source,the production ofaliphatic superplasticizer process is divided into two categories:heat source methodproduction process,no heat production process.The production process of aliphaticsuperplasticizer production is experiencing changes in production process from theheat source to the no heat source production process.No heat source production processis attracted by short production cycle,low energy consumption, stable product quality,safety features.The no heat source process and the inorganic salts sulfonating agentwas systematically researched,and the optimization of process,the effects of reactionconditions about water reduction,the application performance in concrete wasresearched.The experimental results include the following aspects:(1)The performance of aliphatic superplasticizer was effected by The type andamount of the sulfonating agent.The sodium sulfite synthesised heptahydrate aliphaticsuperplasticizer possessed lower prices, better performance characteristics.(2)Based on the results of orthogonal experiment and single factor,the optimalproduction process and optimal ratio of raw materials was determined:the sulfonation agent with acetone molar ratio of0.75,the molar ratio of formaldehyde andacetone2.28;best production parameters: the reactant concentration of52%,condensation reaction temperature90°C,condensation reaction time of3h.(3)After the formaldehyde was added,lignosulfonates reducing agent was added,to improve the fluidity of cement paste,to reduce the loss of fluidity of cementpaste,and to improve water the performance of reducing agent.The dosage oflignosulfonates water reducing agent was15%.(4)Based on infrared spectroscopy data,a sulfonic acid group,a hydroxyl groupand a carbonyl group and a hydrophilic group was determined in the superplasticizerwith the no heat source production process production process(5)Aliphatic superplasticizer mixed with an aqueous solution,was failed tosignificantly reduce the gas-liquid interfacial tension,so the water-reducing agentmixed in the concrete mixture,the gas content of the concrete did not increase rapidly.(6)Aliphatic superplasticizer could extend the setting time of cement and theretarding effect was superior to naphthalene superplasticizer.The dosage with0.7%,compressive strength ratio of195%,170%,163%,and its strengthening effect wassuperior to naphthalene superplasticizer at the age of3d,7d,28d.