The Synthesize of Polymethacrylate Microemulsion and Its Application
|School||Nanjing University of Technology|
|Keywords||microemulsion ternary phase diagram reactive emulsifier microemulsion polymerization Polymer Modified Cement Mortar polymer-cement ratio|
The ternary phase diagrams and the structure of methacrylate microemulsion , the polymerization of methacrylate in ternary oil-in-water microemulsions and its application for the cement mortar were studied systematically in this paper .Following research work has been carried out.First of all, the system of methacrylate/water/ sodium dodecyl sulfate+ pentanol was selected. Its ternary phase diagrams of microemulsion were made . The influence of the temperature and the ratio of emulsifier /assistive emulsifier on the diagram were discussed.With the rising of the temperature,the area of the ternary phase diagrams was enlarged .The appropriate ratio of emulsifier to assistive emulsifier was propitious to the form of the microemulsion. The general emulsifier(SDS) was replaced by the reactive emulsifier(CnNa) ,then the emulsifier content in the microemulsion system failed, at the same time ,the monomer content increased.Conductivity measurement of microemulsion samples was used as one of the techniques to study the microstructure.The study was performed by measuring the conductivity of samples as a function of inceasing aqueous content, keeping the relative amounts of the other chemical species constent.The results of the conductivity measurements as a function of aqueous content for samples from the system containing methacrylate, water, sodium dodecyl sulfate+ pentanol are presented in figure.Three distinct sections of the conductivity-water content curve are observed. The microemulsion system appears to be composed of a W/O droplet structure at low aqueous content, a structure bicontinuous in oil and water at intermediate aqueous content and a droplet structure of O/W at high aqueous content.Based on the aboved experiment , some of the microemulsionABSTRACTcompositions with an O/W droplet structure were polymerized to form stable microlatices. The three factors that influence the conversion -temperature initiator and emulsifier were studied.The general emulsifier(SDS) was replaced by the reactive emulsifier (sodium undecylenate ) ,the monomer conversion was improved when it copolymerized with methacrylate,and the polymer was transparent. Among some definite scope , the monomer conversion will improve with the rising of temperature initiator content and the downing of the emulsifier content.The TEM micrograph shows the microlatex particles formed by polymerizing a microemulsion sample. The measurements of the microlatex indicated the mean particles diameter to be 30 nm .The results of the characterization studies of the precursor microemulsion had indicated microemulsion structure to consist of O/W droplets.After polymerization, the microemulsion was transformed to a microlates of relatively monodisperse polymer particles.The microlatex obtained was observed to be transparent and stable containing reactive emulsifier not the general emulsifier.The MFT is 10.8癈.In this paper , the polymer microemulsion was used to improve the properties of cement mortar for the first time. The application could improve the bending and compressive strength.The stability and particle size of polymer microemulsion are critical factors which determines the properties of Polymer Modified Cement Mortar (PMCM), and the performance of PMCM are also influenced by polymer-cement ratio and curing condition which change the hydtation of cement mortar.