Measurement And Research The Unsaturation Of Macromonomer In Polycarboxylate Superplasticizer

Polycarboxylate superplasticizer is today an important research topic in concrete superplasticizer, is also the best future prospects for the development of concrete admixtures.Currently, the dominant raw material of poly-carboxylate superplasticizer is polyoxyethylene allyl ethers, Modified Polyether/TPEG, Methoxy polyethylene glycol methacrylate/MPEGMA is the derivatives of Methoxy polyethylene glycol ether/MPEG,The quality of raw performance is directly related to the performance of synthetic water-reducing agent. In this thesis, researches the effect of main raw material for the final performance properties of synthetic in the process of synthetic water-reducing agent.Synthesis of polycarboxylic acid analysis process are discussed, APEG and TPEG are synthesized, by unsaturated small monomer as a starting dose and ethylene oxide by anionic ring opening polymerization; MPEGMA are synthesized by esterification of MPEG and MAA. Double bonds are lost in their production process. Therefore, accurate determination degree of unsaturation and double bond retention rate of these key raw materials is particularly important.APEG and TPEG belongs to ether macromonomer, and determing their determination degree of unsaturation and double bond retention rate is by using the method of titrimetric analysis of which the reaction of mercuric acetate and unsaturated polyether. By measuring the water content, pH value and hydroxyl value of the macromonomer, determing the reaction conditions of the method of addition of mercuric acetate, derive accurate determination of methods of analysis double value in ether monomers. MPEGMA belongs to ester macromonomer, determing of such large single double value approach with the classic method of Kaufman, The experiment shows, in the process of synthenizing MPEGMA, Determing of esterification rate and double bond change rate of esterification, best esterification process parameters can be getted. Determination of ester macromer Kaufman double value experimental conditions were determined, the optimal reaction conditions is derived. Ester containing alkenyl ether can also synthesize in theory, but now the manufacturer of such products has not yet produced, therefore this paper is not key to the determination of such monomers to explore.Established a method of polycarboxylate superplasticizer determination of double value of raw materials, inspection of raw materials double value and double bond retention rate of synthesis of the different properties of water reducer. Double bond in different retention rates of similar products in the synthesis of water-reducing agent under the same process, determination of monomer conversion rate, determination of the fluidity of cement paste, concrete and water rates after synthesis of water-reducing agent. The results indicated that the water reducer synthenized by raw matirials of high double value and high double bonds retention rate have many advantages, including large single monomer conversion rate, good fluidity of cement paste, high-performance testing of concrete, high water reduction rate.