Synthesis Of Polymerizable Monomers AAEM And DAAM

Acetoacetoxy ethyl methacrylate(AAEM) is an important methacrylic monomer, As a new style methacrylate functional monomer, AAEM may be reacted with ammonia and hydrazine, and thus can become self-crosslinking, room temperature curing acrylic emulsion ideal monomer. In this paper, hydroxyethyl methacrylate (HEMA) and ethyl acetoacetate (AAA) as raw materials, solid acid as catalyst, ZJ705 as polymerization inhibitor, AAEM was synthesized by the transesterification reaction. The effects of reaction temperature, reaction time, n(AAA):n(HEMA), types and amounts of catalyst and inhibitor on reaction result were examined. The optimum reaction conditions were obtained as following:n(AAA):n(HEMA)=3:1, reaction temperature 130 ℃, reaction time 3 h, the quantity of catalyst was equal to 4.5% HEMA, the quantity of inhibitor was equal to 0.3% HEMA. Under the above conditions, the yield and purity of the product were over 93% and 97%, respectively. The structure of the obtained product was characterized by FT-IR and 1H NMR.Diacetone acrylamide(DAAM) is an important fine chemical product in chemical industries. As a new style vinyl-containing functional monomer, DAAM is available to cause copolymerization, crosslinking reaction, graft reaction and other reactions with other vinyl monomers, and thus is widely used in many fields such as coating, adhesive, epoxy curing agents, additive of textile, additive of photosensitive resin, medical treatment and other fields. The use, prospects, research status and main synthetic routes were introduced in this paper. The advantages and disadvantages of the four synthetic routes were analyzed briefly. Acetone and acrylonitrile as raw materials, the synthetic route of DAAM was discussed in detail. The optimum reaction conditions were obtained as follow:n(aeetone):n(acrylonitrile):n(sulfuric acid)=2.4:1:2.4, the reaction temperature 55 ℃, the reaction time 5 h, the quantity of polymerization inhibitor dosage 0.5%(acetone wt%). After the reaction was finished, it was difficult to extract DAAM from reaction liquid. In this paper, the product extraction process was investigated. When the reaction was over, the reaction mixture was extracted by ammonia water neutralization, water extraction, salting process, washing by alkali and crystallization process. The better parameters of DAAM purification process was obtained. Under these conditions, the melting point of DAAM was 54～56 ℃, the yield and purity of the product were over 65% and 99.3%, respectively. The structure of the product was characterized by FT-IR and 1H NMR.