Synthesis And Performance Of Itaconic Acid Series Polycarboxylate Superplasticizer

Polycarboxylate superplasticizer is the third generation product of high-performance water-reducing.Polycarboxylate superplasticizer become the first choice for HPC because of its own advantanges,such as, excellent dispersing ability, using a wide range, high water-reducing ration,small loss of slump, green environmental protection, etc. In this thesis the research and application actualities of high performance water reducers both in the outside and in the china were introduced in detail, the synthetic methods and the action mechanisms of high performance water-reducers was analyzed. Through the molecule design, synthesis of a new itaconic acid series polycarboxylate superplasticizer.Preparation of methoxy polyethylene glyco esther itaconic acid ester (MPEGIA) for synthesis of polycarboxylate superplasticizer, the mole ratio of the alcohol and acid, the dosage of water-entraining, the dosage of catalyst, reaction temperature and esterification time impact on the esterification rate of methoxy polyethylene glyco esther itaconic acid ester and the esterified macromonomer was successfully prepared. Then, a kind of polycarboxylate superplasticizer using self-made methoxy polyethylene glyco esther itaconic acid ester (MPEGIA), acrylic acid (AA) and 2-acrylamide-2-methyl propane sulfonic acid (AMPS) as the small monomers, acted on the initiator ammonium persulfate to synthesize a kind of novel itaconic acid series polycarboxylate superplasticizer.The influence of various factors on polycarboxylate superplasticizer performance was studied, such as:the monomer mole ratio, reaction time and reaction temperature on fluidity of cement paste. We get the optimum conditions.For the first time, a monomer itaconic acid was copolymerized,acted on the persulfate, with acrylic acid and allyl polyethylene glycol to synthesize a kind of novel itaconic acid series polycarboxylate superplasticizer.The influence of various factors on polycarboxylate superplasticizer performance was studied.Based on the experiment, the best process was obtained. In this paper,we use gel permeation chromatography (GPC) and infrared spectroscoph (IR) to characterize the syntheetic itaconic acid series polycarboxylate superplasticizer, and we get the molecular weight distribution of water reducer and superplasticizer functional groups. Finally, tests were made on properties of the itaconic acid series polycarboxylate superplasticizer. The teseting results show that the self-made itaconic acid series polycarboxylate superplasticizer has good compatibility on a variety of cement and good slump retention in lower dosage.