Preparation Of Short Chain Fluorinated Functional Finishing Agent And Its Application On Cotton Fabrics

The three-proof textile finish can significantly reduce the surface energy of the fabric and give the fabric water,oil,and stain resistance,which has a broad market application.At present,the commonly used C8 type three-proof finishing agent(C_nF_2n+1,n≥8)has been banned from the market due to its biological and environmental hazards,despite its superior performance.Therefore,research and development of environmentally friendly short chain C6 three-proof finishing agent has become a major development trend.However,the fluorocarbon chain of short chain C6 type three-proof finishing agent is short,which makes it difficult to arrange neatly on the surface of the fabric,and easily reconfigured on the surface,resulting in its water and oil repellent performance is difficult to compare with that of long chain C8 type three-proof finishing agent.In addition,existing three-proof finishing agents and products still generally have deficiencies such as durability,feel and odor.In this paper,a short chain fluorinated polyacrylate miniemulsion was prepared by introducing long-chain non-fluorinated monomers into the polymerization system,in collaboration with C6 fluorinated monomers by miniemulsion polymerization,and further modifying the emulsion by introducing different crosslinking monomers on its basis.By studying the effects of crosslinking monomers on polymer properties and washable properties of cotton fabric,the best crosslinking system was selected,and discussed its application on cotton fabrics.The main research details and results are as follows:（1）A short-chain fluorinated polyacrylate miniemulsion was prepared by the miniemulsion polymerization method using tridecafluorooctyl acrylate（C6F）as the fluorinated monomer,octadecyl acrylate（SA）as the long-chain non-fluorinated monomer,methyl methacrylate（MMA）and butyl acrylate（BA）as the base monomers,and 2,2-azobis（2-methylpropylmethane）dihydrochloride（AIBA）as the initiator,in the presence of cetyltrimethylammonium bromide（CTAB）and aliphatic alcohol polyoxyethylene ether（AEO-9）in a complex emulsion.Optimizing the reaction conditions and monomer ratios through testing the properties of emulsion conversion,gelation rate,particle size,PDI,contact angle,and surface energy of the polymer film,etc.The optimum synthesis process was determined as follows:AEO-9:CTAB=1:3,8%of the total mass of monomer,AIBA 1%of the total mass of monomer,reaction temperature 75℃,holding time 5 h,monomer ratios:50 wt%C6F,25 wt%SA,MMA:BA=1:3（w/w）.The surface energy of the prepared miniemulsion polymeric latex film was as low as 9.64 m N·m^-1.（2）The structure and properties of the prepared short chain fluorinated polyacrylate miniemulsion was characterised by particle size analysis（DLS）,infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,thermogravimetry analysis（TG）and differential scanning calorimetry（DSC）.The results showed that the miniemulsion had uniform particle size distribution and good stability The surface F content of the polymer emulsion film reached 41.01%,and its crystalline strength was enhanced with the increase of SA content.When the mass ratio of C6F/SA was 2:1,the synergistic effect of SA and C6F was the best.Meanwhile the polymer had better film formation and heat resistance stability.（3）Three crosslinking monomers,γ-methacryloxypropyltrimethoxysilane（KH-570）,diacetone acrylamide（DAAM）,and trimethylolpropane triacrylate（TMPTA）,were introduced into the polymerization system respectively.The effects of the amount of crosslinking monomer on the properties of emulsion and the contact angle and surface energy of latex film were investigated.The water washing resistance of cotton fabric treated with crosslinking short chain fluorinated polyacrylate miniemulsion was investigated.The structure and properties of crosslinking short chain fluorinated polyacrylate miniemulsion were characterized by FTIR,XRD and TG.The research results showed that the crosslinking monomers had been successfully introduced into the polymer and were beneficial for improving the thermal stability and crystalline strength of the polymer;The dosage of three crosslinking monomers was optimized,and the optimal crosslinking monomer was KH-570.（4）The KH-570 crosslinking modified short chain fluorinated polyacrylate miniemulsion was applied to cotton fabric,and the optimal finishing process was optimized.The cotton fabric finished by this process had a water contact angle of150.5°,an olive oil contact angle of 140.7°,a water repellency grade 4,an oil repellency grade 4,and a stain resistance grade 4-5,with good triple protection properties and unaffected wearing properties.After 20 washings,the finished cotton fabric still maintained good water and oil repellency,and had good water washing resistance.