Preparation And Properties Of Crosslinking Fluorinated Acrylate Copolymer Emulsion

The fluorinated acrylate polymer have been widely used in the fields of building, oil exploitation, coatings, textile, leather and packaging because of its excellent stability, weather resistanee, water repellency,oil resistance and low surface energy. However, since uncrosslinked fluorinated acrylate polymer are a linear molecular strueture, the gloss, solvent resistance and water resistance of films are poor. The hardness and mechanical properties of films has not meet the requirement of application in many the fields. Therefore, in order to further improve the mechanical behavior of emulsion resin, how to make fluorinated acrylate polymer into network structure by crosslinking modification, has important theoretical and realistic significance.In this work,the three-crosslinking system was used to modify fluorinated acrylate polymer. The influence of the amount of the fluorinated monomers and three crosslinkingable monomers on the properties of copolymer emulsion and films was studied. The main contents of this paper are as follows:1. The structure and properties, research progress, applications of the fluorinated acrylate copolymer emulsion were reviewed. The crosslinking technology and research progress of fluorinated arcylate copolymer emulsion were introduced.2. The self-cross linking fluorinated acrylate copolymer emulsion were synthesized by semi-continuous seed emulsion polymerization with methyl methacrylate(MMA), butyl acrylate(BA) as main monomers, dodecafluoroheptyl methacrylate (DFHMA) as fluorinated monomer, N-hydroxymethyl acrylamide(NMA) as crosslinking monomer and polyoxyethylene octyl phenyl ether(OP-10) and sodium dodecyl sulfate(SDS) as emulsifier. Effects of the DFHMA and NMA amount on the properties of emulsion and films were investigated. The structure, morphology and thermal properties of the products were confirmed using FTIR, TEM and TG The results show that the emulsion has good stability and small particle size, narrow size distribution when the amount of DFHMA is6%and the amount of NMA is3%.The average particle size of the latexes is48nm and thermal stability and solvent resistance of films are markedly improved when the moderate amount of NMA is introduced into the mixed monomers.3. The external crosslinking fluorinated acrylate copolymer emulsion were synthesized by semi-continuous emulsion polymerization with hexafluorobutyl methacrylate (HFMA) as fluorinated monomer, glycidyl methacrylate (GMA) as crosslinking monomer. Effects of the order of adding GMA and GMA amount on the properties of emulsion and films were investigated. The results show that the water resistance and solvent resistance, mechanical properties of the films increased gradually with increase of GMA amount. The highest overall conversion of monomer is96.58%, and emulsion has excellent Zeta potential stability, narrow size distribution when the amount of GMA is4%in core. The average particle size of the latexes is30-40nm.4. The self-crosslinking fluorinated polyacrylate latices (SFPL) with core-shell structure at ambient temperature were synthesized by seeded emulsion polymerization with diacetone acrylamide (DAAM) and adipic dihydrazide (ADH) as crosslinkable monomers. The influences of mole ratios of ADH to DAAM and DAAM monomer content on the properties of self-crosslinking fluorinated polyacrylate lattices were discussed. Besides, the structure and morphology of latices particle were characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and differential scanning calorimetry (DSC), respectively. FT-IR spectra showed that the keto-carbonyl groups of diacetone acrylamide (DAAM) reacted with acylhydrazino groups of adipic dihydrazide (ADH) and all monomers formed the fluorinated polyacrylate copolymer. TEM and DSC showed that the resulted latex particles had the core-shell structure. The thermal stability and Tg of the shell phase increased gradually with increasing of DAAM amount in polymer. The hardness and water resistant of SFPL were clearly enhanced when adding the cross linker DAAM and ADH.