Soap-Free Emulsion Polymerization And Modification Of Cement Base Material

Usually cement-based materials are all inorganic heterogeneous brittle material,it has better compression performance,But bending,impermeability and other aspects of defects limiting the application of practical aspects.Of the polymer itself flexibility,adhesion and other properties just to make up the shortage of cement-based materials,greatly enhance the durability and workability properties of cement-based materials.Today,polymer modified cement-based materials are widely used in marine engineering?waterproof anti-corrosion materials and construction and other fields.Modified cement-based research materials commonly used in the form of an emulsion polymer based,conventional emulsion polymerization need to add emulsifiers and protective colloids to ensure the stability of the polymerization system.However,neither the two polymerization reaction involved,and the performance of the emulsion prepared and modified cement-based material adverse effect,furthermore,there is little environmental pollution.Free emulsion polymerization is a new technology without adding emulsifiers and distinguished from conventional emulsion polymerization,preparation of binary soap-free emulsion had a solid content and stable performance are deficient.In this paper,vinyl acetate,butyl acrylate monomer as hard and soft monomer,acrylonitrile and acrylic acid as functional monomer,ammonium persulfate(APS)as an initiator,female-nonionic comonomer(SMAS,VPEG)formed copolymer environment,by semi-continuous emulsion polymerization process to prepare ternary and quaternary soap-free acrylic emulsion vinegar.Comparative analysis of two pluralistic soap-free emulsion performance advantages and disadvantages,Using the better overall performance pluralistic soap-free acrylic emulsion vinegar,studying the effect of cement-based materials performance trends.Detailed work is as follows:1.Using the test method of six factors and five levels orthogonal design,weare determined ternary and quaternary soap-free emulsion vinegar C optimum conditions,by comparing the analysis of the two non-soap emulsion vinegar C various properties with infrared characterization,observed two kinds of fine soap-free vinegar C emulsion stability,however,quaternary soap-free vinegar C emulsion solids content and adhesion are higher than ternary soap-free acrylic emulsion vinegar,the results showed that quaternary soap-free emulsion vinegar C excellent integrated nature.2.Using quaternary soap-free emulsion vinegar C to research modified cement-based materials,it was analyzed by a variety of performance.(1)Analysis quaternary soap-free emulsion vinegar C for changing in cement standard consistency water and setting time,with the increase of the amount of polymer,reducing the amount of standard consistency,setting time slightly extended,description quaternary soap-free emulsion vinegar C cement-based materials with water-reducing effect;(2)Fixed 1: 3 ratio of gum sand,water-cement ratio is 0.5,research added antifoaming agent quaternary soap-free vinegar C latex-modified cement-based materials' trends in performance under different curing conditions,Concluded that,quaternary soap-free emulsion vinegar C significantly improved performance and durability performance of cement mortar,polymer in an amount of 1%,modified mortar has the highest flexural strength,it is found that the properties of modified cement mortar using 7d standard curing and 21 d room temperature curing effect on the performance of the development of modified cement-based material is preferably,In terms of barrier properties is particularly significant.After adding antifoaming agent also found that severely reduced the production rate of the bubble,the more closely the modified cement mortar structure,significantly improved the performance of antifreeze modified cement mortar.3.Quaternary soap-free emulsion vinegar C latex-modified cement pastes were characterized by X-ray diffraction analysis and infrared spectroscopy methods,explore the role of changes observed between quaternary soap-free emulsion andcement hydration products.Application of SEM scanning electron microscopy quaternary soap-free vinegar C latex modified cement mortar microstructure,analysis of changes in the structure of polymer and cement mortar interface transition region.