The Synthesis Of Fluorined Water Repellent Finishing Agent

Fluoropolymer finishing agent exhibits some unique properties due to it contains thestrong electronegative atom fluorine, so that it can impart excellent water repellency to thefinished fabric, but doesn’t affect the nature properties of the fabric. Therefore, thefluorine-containing finishing agents attract more and more attention and developedcontinuously in recent years. However, the price of the fluorine-containing monomer isexpensive, in order to improve the effective utilization of the fluorine-containing monomer, itis becoming a trend of development to study the fluorinated finishing agent with highperformance, low cost and environmental.In this paper, using styrene(St), isooctyl acrylate(EHA), dodecafluoroheptylmethacrylate(G-04) and hydroxyethyl acrylate(HEA) as the main raw materials,choosing the anionic emulsifier sodium dodecyl benzene sulfonate(LAS) and the non-ionicfluorinated emulsifier(FS) as compound emulsifier, under the action of potassiumperoxydisulfate(KPS) as initiator, the core-shell type structure of fluorine-containingpolymer emulsion was synthesized by the semi-continuous seed emulsionpolymerization and pre-emulsification process, in which the fluorine-containingpolymer as the shell layer and non-fluorinated polymer as nuclear layer.By studying the factors, such as emulsion polymerization method, the fluorinatedmonomer’s choice and dosage, the ratio of non-fluorinated monomer, the emulsifier’s type,ratio and dosage, initiator dosage, polymerization temperature, holding time, and the amountof hydroxyethyl acrylate which affect the performance of polymerization reaction andpolymer emulsion, the optimal synthesis conditions was determined. And the morphology,structure and thermal properties of the synthesized core-shell fluoropolymer emulsion wereanalyzed by some test instruments like transmission electron microscopy(TEM), Fouriertransform infrared spectroscopy(FT-IR) and thermogravimetric analysis(TGA). The resultsshow that, when the amount accounting for the total mass of the polymerizable monomer ofG-04, compound emulsifier LAS/FS, KPS, and the crosslinking monomer HEA was34%,3%,0.8%,2.5%respectively, the ratio of EHA/St was1.2, the ratio of LAS/FS was3:2, thequality ratio of core and shell emulsifier was1.5, the polymerization temperature of80℃, theshell monomer dropping time was90min, and holding90min, a core-shell type structure containing fluorine polymer emulsion with milky, pan blue, stability good can be made.In this experiment, different dosage of G-04, mixed emulsifier LAS/FS, KPS and HEAcontained in the fluoropolymer affect the water repellency of fabric were investigated. Theresults showed that the fluorine-containing monomer G-04was the biggest effect on the waterrepellency of the fabric, the water repellency of the fabric with the amount of G-04increasedwas getting well, when it reached a certain value no longer changed. The crosslinkingmonomer HEA for fabric has a great impact on the water resistance, increase the amount ofHEA can improve the fabric washing performance.By studying the different dosage of finishing agent, pre-baking temperature and bakingtime and temperature affect on the water repellence of fabric, determined the best applicationprocess of the water repellent finishing agent for pure cotton fabric, and discussed thephysical properties of cotton fabric after finishing, as whiteness, permeability, breakingstrength, wrinkle recovery angle changes. The results showed that the best application processof the fluorinated water repellent finishing agent: cotton fabric→two dip two rolling(waterrepellent finishing agent60g/L)→drying(80℃,3min)→baking(170℃,3min), cotton fabricafter finishing the water contact angle is137.8°, and it has litter effect on the original style ofthe fabric. Finally, through the scanning electron microscopy(SEM) on the cotton whichbefore and after finishing was studied.