Preparation Of Perfluoropolyether-containing Polyacrylates And Their Application On Cotton Fabrics

Fluorinated acrylate monomers la,1b and lc were synthesized starting from methacryloyl chloride and dimeric, trimeric or tetramic perfluoropolyether alcohol in78%、82%and80%yields respectively. Fluorinated methacrylate monomers4a and4b were synthesized from methacryloyl chloride,4-hydroxybenzoic acid and dimeric or trimeric perfluoropolyether alcohol in80%and75%yields. Fluorinated methacrylate monomers were characterized by NMR and FT-IR spectra.The fluorinated methacrylate monomers were copolymerized with methyl acrylate, n-butyl acrylate and2-hydroxyethyl acrylate to form copolymer emulsions PFA. TO-5and SDS were used as emulsifying agents and APS as an initiator in this paper. The influences of polymerization conditions such as concentration of initiator, time and temperature of reaction, concentration of fluorinated monomers on stability of copolymer emulsions and water-oil repellent of copolymers were studied. The emulsion polymerization was modified and copolymers PFA1-2, PFA2-2, PFA3-2, PFA4-2and PFA5-2were obtained with effective water and oil repellent properties. The particle size and distribution of emulsions were measured and the structures of PFA were characterized by FT-IR. Their thermal stabilities were also investigated by TGA.Copolymer emulsions were diluted with water to form5%emulsion. These emulsions were applied on cotton fabrics by pad-dry process.The change of external geometry morphology of the fabrics before-or after-treatment were shown by SEM and the element content on the fabric surface was analyzed by XPS. Copolymer PFA5-2containing trimeric perfluoropolyether side chain and phenyl spacer group achieved excellent water and oil repellency. The cotton fabric treated by PFA5-2had contact angle of146°for water and120°for n-dodecane respectively Copolymer PFA2-2containing trimeric perfluoropolyether side chains achieved less effective water and oil repellency as compared with PFA5-2. The cotton fabric treated with PFA2-2had contact angle of145°for water,108°for n-dodecane. Copolymer PFA4-2containing dimeric perfluoropolyether side chain and phenyl spacer group achieved general water and oil repellency, the contact angle for water reached142°, and120°for n-hexadecane. Its counter part, copolymer PFA1-2achieved less effective water and oil repellency as the contact angle reached138°for water and108°for paraffin oil. Copolymer PFA3-2containing tetramic perfluoropolyether side chain had comparative water and oil repellent properties as PFA2-2as the contact angle reached144°for water and108°for n-dodecane.In a word. the trimeric perfluoropolyether side chain is essential for such PFAs to obtain sufficient water and oil repellent properties, and the phenyl spacer group is useful for PFAs to achieve good water and oil repellent properties as well.