Preparation Of The Silicone-acrylate Emulsion And Its Application In Paper

Waterborne silicone-modified acrylic systems combined the mechanical strength of the acrylic polymers with the good water repellency and thermal resistance of the silicones become a research hotspot all over the world, which lead them to be widely used in the regions of high weather-resistance antipollution coatings, textile finishing paper surface sizing, paper reinforcement as well as softening. However,both of the lower monomer conversion and unstability of the latex during the emulsion copolymerization were investigated owing to the diffusive difficulty of the high water-resistant alkoxysilane monomers in water and their inherent hydrolysis characteristics, which became tough problems to limit their usage. In this work, two strategies of miniemulsion polymerization and emulsion copolymerization of the vinyl terminated silicone prepolymer with acrylic monomers were employed to overcome these problems.Miniemulsion polymerization technology was used to prepare polydimethyl-siloxane emulsions in this thesis. Octamethylcyclotertrasiloxane(D4) was used as monomer,sulfuric acid or hydrochloric acid as catalyst,sodium dodeeylbenzene sulfonate(SDBS)as surfactant,hexadecane(HD)as co-stabilizer , and ultrasonication as Pre-emulsification method. A polydimethylsiloxane emulsion provides a way to improve these scouring property and stability of polydimethylsiloxane emulsion. The effects of ultrasonieation, surfactant concentration, monomer concentration, costabilizer concentation and catalyst concentration on partiele size and miniemulsionstability were investigated.The technological conditions of stable miniemulsion polymerization were obtained.The pre-semi-continuous seed emulsion polymerization method was used to prepare core/shell-based silicone-modified styrene-acrylic copolymer emulsion; The structure,heat resistance of the emulsion was characterized by FT-IR,DSC. The result shows that silicon -acrylic not only to maintain the mechanical properties of impregnated paper, but also can effectively improve the softness of paper. Silicon -acrylic emulsion would be widely applied in the field of household paper as a new typy of soft agent.Based on the previous work of our gtoup, we make the DV-PDMS as a shell monomer to copolymer with the acrylic emulsion. Silicone modified acrylate copolymer emulsion was successfully synthesized. The structure,heat resistance,hydrophobic resistance of the latex particles of the emulsion was characterized by FT-IR,DSC,surface contact angle analyzers.The surface morphology of the filter paper was characterized by SEM. This paper discusses the influence of DV-PDMS addition on copolymer structure,properties of polymer surface,and mechanical properties,heat resistance and hydrophobicity of enhanced filter paper.