| Aiming at the problems of formaldehyde pollution in indoor air as well as free formaldehyde in some adhesives,this paper was studied to modify the acrylic resin with an active methylene monomer by free radical polymerization in order to give it a function of purifying formaldehyde and so that,it can be applied to purify the formaldehyde in indoor air as well as free formaldehyde in adhesives.The acrylic resin with active methylene was prepared with an active methylene monomer by free radical solution polymerization.The influences of polymerization temperature,amount of initiator,monomer ratio and other factors on the properties of the resin were investigated and in addition,the properties of the resin were analyzed by infrared,thermogravimetric,differential calorimetry and other analytical methods.The results showed that when the polymerization temperature was 85℃,when the amount of initiator of the amount of monomer was 1.5%,when the amount of solvent was the same as the amount of monomer as well as when the amount of acetoacetate ethylene glycol methacrylate of the total amount of monomers was 12%,the prepared acrylic resin was light yellow transparent viscous liquid with good water solubility and at the same time,its viscosity was 727.5m Pa.s as well as its solid content was 53.5%.Moreover,there were hydroxyl,carboxyl and carbonyl in the prepared acrylic resin that was thermally stable with the glass transition temperature was44.73℃.In the formaldehyde purification simulation experiment,it showed that when the initial concentration of formaldehyde in the closed box was 1.3～1.4mg/m~3,the prepared acrylic resin can remove 85%of formaldehyde.In the experiment of purifying the free formaldehyde of the adhesive of an enterprise,it showed that when the free formaldehyde content of the adhesive was 0.36%,the amount of free formaldehyde in the adhesive can be removed about 30%after adding the modified acrylic resin.An acrylic emulsion was also prepared with an active methylene monomer by free radical emulsion polymerization.The influences of different kinds of emulsifiers,polymerization temperature,amount of initiator and other factors on the properties of the acrylic resin were investigated and in addition,properties of the acrylic resin were analyzed by infrared,thermogravimetric,differential calorimetry and other analytical methods.The results showed that when the amount of emulsifier was 3%,when the polymerization temperature was 85℃as well as when the amount of initiator of the amount of monomer was 0.8%,the acrylic emulsion was milky white blue liquid with good water solubility and at the same time,its viscosity was 220.5m Pa.s as well as its solid content was 54%.Moreover,there were hydroxyl,carboxyl and carbonyl in the prepared acrylic resin that was thermally stable with the glass transition temperature was 14.2℃.In the formaldehyde purification simulation experiment,it showed that when the initial concentration of formaldehyde in the closed box was1.4～1.5mg/m~3,the prepared acrylic emulsion can remove 75%of formaldehyde.In the experiment of purifying the free formaldehyde of the adhesive of an enterprise,it showed that when the free formaldehyde content of the adhesive was 0.36%,the amount of free formaldehyde in the adhesive can be removed about 26%after adding the modified acrylic emulsion.Several kinds of materials that can purify formaldehyde were compared and screened in this study.In addition,the dispersion differences in the prepared acrylic resin between these materials were analyzed.The results showed that ethyl acetoacetate,activated carbon and shell powder had a better effect on purifying formaldehyde and however,acrylamide had a lower ability to purify formaldehyde.Besides,the dispersibility of ethyl acetoacetate and acrylamide in the resin was better than that of activated carbon and shell powder and besides.By the way,there was no obvious change in the appearance of acrylic resin while both of shell powder and activated carbon had a obvious change in the appearance of acrylic resin.It can improve the dispersibility of the shell powder in the acrylic resin when the shell powder was modified by chemical methods and moreover,it can also improve the dispersibility of the shell powder in the acrylic resin by using free radical polymerization to prepare the shell powder-acrylate polymer. |
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