Synthesis Of Solid Polycarboxylate Superplasticizer Based On TPEG As Macromer

Now commercially available polycarboxylate superplasticizer?PCE?is mainly liquid,which may greatly increase the cost for long distance transportation.Powdery PCE must be needed in the field of production of dry powder mortar.Therefore,it is imperative to synthesize solid powdery PCE for reducing the cost and expand the field of application.Researches at home and abroad have begun to explore the production process of solid PCE,but most of them are still focus on the drying of product of solution polymerization.However,these methods are not ideal methods for synthesizing solid PCE due to their high energy-consumption and low safety,etc.This paper attempts to synthesize solid PCEs by bulk polymerization using TPEG with different molar weight as macromer.This method possesses the advantages of high efficiency,low energy consumption,and non-pollution.The main contents are as follows:?1?The PCEs synthesized by bulk polymerization using TPEG₄₀₀₀ as macromer and AIBN as the initiator under the three different initiation systems.The optimal conditions were:acid/ether ratio=5,w?AIBN?=0.5%,w?mercaptopropionic acid?=0.2%,w?3203B?=0.5%.The cement paste fluidity achieved satisfactory as the PCE is 2%.?2?The PCEs synthesized by bulk polymerization using TPEG₂₀₀₀ as macromer and AIBN as the initiator under the three different initiation systems.The optimal conditions were:acid/ether ratio=4,w?AIBN?=0.3%,w?mercaptopropionic acid?=0.5%,T=75°C,reaction time is 3 h,the dropping speed is 1.8.The cement paste fluidity achieved satisfactory as the PCE is 1.2%.This paper has initially explored the preparation conditions for the synthesis of solid PCE by bulk polymerization.After further improvement,it has a positive effect on promoting the marketization of solid PCE,providing new ideas for the industrial production of solid PCE,and having reached the international leading level for concrete water-reducing agent in China.