Synthesis And Properties Of Polycarboxylate Superplasticizer With Propylene Epoxide Block Copolymerized Linear Polyether Macro-monomer

This article relies on the sub-topic of the research of the national “12thFive-Year” Technology Support Program "The research and demonstration of keytechnology with low-cost, low-power buliding energy"（2011BAJ03B03）ThePolycarboxylate on the market have many issues like poor adaptability, dispersionunstable and so on. By modified Polycarboxylate materials polyethermacromonomer to modify Polycarboxylate, Use infrared, viscosity, Usedetermination of the degree of utilization of slurry flow, rheological properties,adsorption, concrete performance tests to determine whether the modified polyethermonomer synthesis Polycarboxylate modified to achieve the purpose. The details areas follows:1By studying the self-developed sample`s infrared spectrum and NMR spectrato determine the feasibility of block monomers.Determined from the structure of theircompliance with the design requirements, to lay the foundation for the next modifiedwater reducer product.And by the determination of thermal analysis and viscositypolyether modified to study the effects of process block EO/PO for modifiedpolyether The results were as follows:By fractional added EO, PO, EO and catalyst to start with a high-pressure reactor,modified polyether blocks may be prepared. The infrared spectrum showed thatpropane and propylene oxide block polyether modified content in different spectrumof the sample,975cm-1appears at the absorption peak, and975cm-1band isrepresented by an ethylene oxide chain-CH2-rocking vibration and propylene oxidesegments of the adjacent segments. This indicates that the composition of ethyleneoxide/propylene oxide copolymer is the expected molecular structure in accordancewith our design, the segment portion is EO or PO polyether concentration distribution.That is, two different types of monomers in the polyether chain linked to one anotherare each concentrated, and not irregular distribution, in accordance with EO-PO-EOdistribution. NMR nuclear magnetic resonance spectra further confirmed by thesynthesis of the polyether consistent with the design of the structure. EO/PO blockmodified polyether proportional impact on performance: With the increase of EO/ PO viscosity modified polyether block increases, the surface tension increases, theweight loss rate..2By studying the block with a modified monomer polymerization temperaturesynthesis when water reducer liquor, reaction time, monomer ratio and the amount ofinitiator modified polyether block to determine the best Polycarboxylate synthesisThe results showed that:Through discussion of the polymerization reaction temperature, reaction time,monomer ratio and the amount of initiator, such as synthesis, with the fluidity ofcement paste as characterization, modified polyether block to get the bestPolycarboxylate Synthesis namely: monomer ratio EPE: AA=1:3.3, wherein theamount of initiator is0.5%hydrogen peroxide, and the reaction time was5hours, thereaction temperature was60℃. The synthesis process synthesized block modifiedpolyether polycarboxylate superplasticizer paste fluidity best, indicating that theoptimal reaction conditions for the synthesis process.3Synthesized by modified polyether block Polycarboxylate cement paste andconcrete conducted experiments to determine the performance of the modified waterreducer, compared to traditional non-modified water reducer to reveal the modifiedminus agent superiority, the results showed that:In order to study the synthesis of the Institute superiority modified polyethercarboxylic acid superplasticizer HEPE series of different concentrations of HEPEseries Polycarboxylate and comparison group HPC solution Polycarboxylate surfacetension, saturated content, measured fluidity of cement paste and the loss, therheological properties of cement paste, concrete properties, the data show homemademodified HEPE series polycarboxylate HPC compared to conventional non-modifiedpoly acid water reducing agent with a low dosage of high fluidity, slump,compressive strength ratio advantages; oxide block modified polyetherpolycarboxylate cement particles dispersed can play a better role; guaranteecompressive strength and mobility and the loss, while improving the initial pastefluidity; at a lower dosage of superplasticizer, the concrete is still able to obtain ahigher degree of mobility.