Preparation And Properties Of Water-Resistant Modified Waterborne Acrylate Resin

Water-based acrylic resin uses water as solvent,which is in line with the future development direction of green environmental protection.It is widely used in coatings,textiles,adhesives,inks and other fields due to its excellent film forming properties,adhesion,gloss and corrosion resistance.However,because of its high surface energy,acrylic resin is lacks of water resistance and antifouling performance,which limits the development of acrylic resin to high-level fields.Therefore,the paper prepared modified waterborne acrylic resins to improve its water resistance and tensile strength.Firstly,a series of water-based acrylic resins were prepared by using methyl methacrylate and butyl acrylate as the main polymerization monomers and vinyl neodecanoate as functional monomers.Using the new reactive emulsifier LRS-10,the emulsion is stable and fine,its cohesion rate is low,and the water absorption rate is lower than that of the conventional emulsifier.And the optimum amount is 3.5%.Based on this,the structure and properties of vinyl acrylate-modified acrylate resin were studied.The results show that the synthetic emulsion has a core-shell structure,its thermal stability is improved,and the initial decomposition temperature is delayed by about 30 ℃.The most obvious thing is that the water resistance of the resin is improved.When the content of modified monomer is 12%,its water contact angle is 112°,contact angle of ethylene glycol is 107°,diiodomethane contact angle is 84°,and water absorption rate of 48h is 4.4%,and the calculated surface energy is 12 mN/m.To improve the water resistance of the acrylic resin by utilizing the low surface energy of the fluorine-containing acrylate.The addition of the fluorinated emulsifier FS3100 can reduce the tension between the liquid surfaces and promote the smooth reaction of the fluorine-containing monomer,and the optimum addition amount is 0.1%.Four kinds of fluorine-containing monomer modified resins with different structures were selected,and the contact angle of the film was obviously improved.The longer the length of the fluorine-containing segment,the greater the increased.2-(Perfluorooctyl)ethyl methacrylate was selected as the modifying monomer.The structure and properties of the prepared acrylic resin were tested.Infrared spectroscopy showed that the fluorine-containing monomer had been incorporated into the polymer.The particle size analysis showed that the emulsion was fine and the particle size was small.When the fluorine monomer was added,the initial decomposition temperature of the resin was delayed by about 40℃,and the maximum decomposition temperature was also delayed which indicat that the thermal stability of resin was improved;the modified acrylic resin with 12%fluorine-containing monomer has the best hydrophobic oleophobic and antifouling properties.The water contact angle of the film is 127°,contact angle of ethylene glycol is 121°,and contact angle of diiodomethane is 111°,the calculated surface energy is only 4.7 mN/m,and the water absorption rate is 2.8%at 48h.X-ray photoelectron spectroscopy shows that the fluorine-containing segment has a tendency to migrate to the surface during film formation,thus reducing the surface energy of the film.This contact angle data provides evidence.The third part of the thesis is the preparation of polyurethane modified acrylate,which improved the water resistance by virtue of its dense structure.Compared with the emulsion prepared by the mixing method and the graft copolymerization method,the new copolymer emulsion is more stable,has less sedimentation,and has good film forming properties.This experiment conducted a series of tests on the structure and properties of the resin.Infrared spectroscopy characterizes its structure.The particle size diagram shows that when the content of the two parts of polyurethane and acrylate is equal,the particle size of the resin is large,the distribution is widened,the segments are staggered,and the density is large.The contact angle of the film water can reach 109°,the surface energy is as low as 15.7 mN/m,and the water absorption rate is low,indicating that the polyurethane can improve the water resistance of the resin within a certain range.At the same time,polyurethane modified acrylate can improve its thermal stability and mechanical properties.The tensile strength of the polymer increased from 1.80 MPa to 8.70 MPa.