Study On Synthesis Process Optimization And Properties Of Low-cost Naphthalene Superplasticizer

At present, naphthalene superplasticizer is still most widely used in China. Thesupplies of crude naphthalene are growing tension, which lead to a sharp rise in theprice of naphthalene superplasticizer in recent years. Therefore, other low pricesmonomers are used in the production of naphthalene superplasticizer to synthesizenaphthalene superplasticizer,which is the most effective measure to reduce the cost ofsuch superplasticizer.According to this, with the main materials of wash oil/crude naphthalene, calciumlignosulfonate/crude naphthalene, two types of naphthalene superplasticizer weresuccessfully designed and synthesized in the paper. The synthesis process parameterswere optimized and regulated with single-factor and orthogonal experiment, at thesame time, adapatability with cement, compressive strength and water reducing rate ofconcrete were measured. From the tests, the following conclusions are drew:The sulfonation temperature, condensation time of the naphthalenesuperplasticizer synthesized with part of wash oil were equivalent to those synthesizedwith all crude naphthalene, but the sulfonation time of former should be properlyextended, the sulfuric acid content of former should be properly extended and theformaldehyde content of former should be properly reduced; On the basis ofoptimization of synthesis process parameters, wash oil could replace25%~30%ofcrude naphthalene, the naphthalene superplasticizer owned the same propertyessentially but enjoyed a significant reduction in costs.The dropping formaldehyde temperature of the naphthalene superplasticizersynthesized with part of calcium lignosulfonate was equivalent to those synthesized with all crude naphthalene, but the dropping formaldehyde time and the condensationtime of former should be properly extended, the condensation temperature of formershould be properly incresed. On the basis of optimization of synthesis processparameters, the naphthalene superplasticizer synthesized with15%of calciumlignosulfonate owned similar property with those synthesized with all crudenaphthalene but enjoyed a significant reduction in costs.In addition,the compound performance of naphthalene superplasticizer andcalcium lignosulfonate water reducing agent was also studied. The compound effectsof two types of water reducing agent in different compound proportion were measuredthrough cement paste and concrete tests,and the best compound ratio were optimized.The results showed: Compared with the situation of naphthalene superplasticizer usedseparately, calcium lignosulfonate water reducing agent was used together with thenaphthalene superplasticizer,which could increse the initial fluidity of cement paste butcouldn’t improve loss of fluidity of cement paste,on the other hand, which couldimprove water-reducing ratio but contributed little to the compressive strength,even thecompressive strength would be decresed when calcium lignosulfonate over-doped.Thebest compound ratio is0.75%naphthalene superplasticizer and0.2%calciumlignosulfonate. The naphthalene superplasticizer had good compound performance inlower proportion of calcium lignosulfonate.To sum up, the research on synthesis process optimization and properties oflow-cost naphthalene superplasticizer, can comprehensively utilize natural resourcesand reduce production costs, has the very improtant economic, social and practicalvalue on naphthalene superplasticizer industrialized production.