Study On The Preparation And Property Of Low-foaming Poly-acrylate Adhesive

At present,The major production of polyacrylate adhesive adopt emulsion polymerization, one of the most important process is emulsification which draw support from the emulsifier. In order to achieve good results, it is often used to select good emulsifier such as sodium dodecyl sulfate(K-12), fatty alcohol polyoxyethylene ether(AEO), sodium dodecyl benzene sulfonate(SDBS).These SAA have good emulsifying ability at the same time and also have strong power of foam, which means the synthesized product is easy to foam, bubbles generated in the production, transportation and application bring the unnecessary troubles.The addition of defoamer can only reduce foam temporarily and will affect the performance of the product, so this thesis is aimed at reducing the frothing capacity of polyacrylate emulsion and studing its application performance without the defoamer.This thesis adopted the reformed pre-emulsification semi-continuous process,used the low-foaming fatty acid methyl ester sulfonate(FMES)and Pluronic PE6400 as emulsifiers,methyl methacrylate(MMA) as hard monomer, 2-ethylhexyl acrylate(2-EHA) and butyl acrylate(BA) as soft monomers,acrylic acid(AA) and acrylamide(AM) as functional monomers,hydroxyethyl acrylate(HEA) and DS-65 as crosslinking monomer,ammonium sulfate(APS) as initiator to prepared the low-foaming polyacrylate emulsion,then vinyl silicone oil(600cs) was used to modifying the low-foaming polyacrylate emulsion.The low-foaming and temperature self-crosslinking polyacrylic emulsion was synthesized through taking DS-65 substituted hydroxyethyl acrylate as crosslinking monomer.The optimum of the low-foaming polymer emulsion were determined by single factor and orthogonal analysis:emulsified monomer by 60 minunder the rotate speed of 3000r/min,set the temperature of reaction at 85℃ and the dropping rate of pre-emulsion at2 m L/min,insulated for 30 min under 90 ℃ after polymerization was conducted. Selected the ratio of emulsifier of FMES / PE6400 by 3/4 and the dosage is 0.6%, the dosage of initiator was 1.0%, the dosage of functional monomer was 4%, the dosage of cross-linking monomer was 2%, the dosage of vinyl silicone oil was 6%,the solids content was set by50% and the theoretical glass transition temperature was set at about-15 ℃.The appearance of low-foaming polymer emulsion was uniform,milky,had a bluish tinge, the result of solids content was 50 ± 3%, centrifugal stability, dilution stability, calcium ionstability were good, the blistering rate was 6%, the foam volume of polymer emulsion increased marginally after shocking one more time.The polymer emulsion were characterized by using particle size analyzer, infrared spectroscopy and simultaneous thermal analyzer.The particle size analysis shows that the particle size of low-foaming polyacrylate emulsion distribution substantially 80-300 nm,the average particle diameter was 125.5nm; FTIR spectra showed that all the monomers reacted completely, there were characteristic peaks of Si-O bond and Si-CH3 bond in silicone-modified polymer spectrum; The TG analysis showed that the silicone-modified polyacrylate had a high decomposition temperature required and the heat resistance is improved.The prepared low-foaming polyacrylate emulsion and modified polymer emulsion were used in pigment printing, crease resistant finishing and anti-pilling finishing, and the friction color fastness degree, soaping fastness, wrinkle recovery angle, pilling, softness,whiteness, breaking strength,breaking elongation and others were tested. The test results show that the low-foaming polymer emulsion prepared can achieve better color fastness of friction and soap; using DS-65 as a cross-linking monomer of emulsion adhesive can be obtained good cross-linking effect when the baking temperature more than 130℃and the strength and whiteness of fabric reserved well;the polyacrylate emulsion used acrylamide as functional monomer can make the fabric elastic reply acute angle reaches 282°, slow bomb reply angle reaches 305°;Silicone modified polyacrylate emulsion can make the pilling resistance of fabric increased into four and a half grade,and improve hand-feeling of fabric effectively as well.