Study On Synthesis Of Diacetone Acrylamide

Diacetone acrylamide(DAAM) is an important fine chemical product.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 widely applied in many fields such as coating,adhesive,additive of photosensitive resin,medical treatment and so on.At present,only in a few developed countries abroad such as America,Japan,the industrialized production of DAAM has been carried out,anal approximate 10kt of annual yield of production is achieved.Experimental production of DAAM is reported domestically,and the need of DAAM has been met mainly by import from other countries.Therefore,technical optimization of DAAM has great economic and social benefits.In the present work,DAAM is prepared with acetone and acrylonitrile as materials, sulfuric acid as catalyst through deep studying on many kinds of synthesized method and purification of product.In this process,intermediate of product is synthesized firstly,and then distilled by crystallization.Product is obtained by neutralization with intermediate.On account of polymerization tendency in the synthesis reaction,hydroquinone is elected as optimal inhibitor by discussion.Technical conditions of distilling the intermediate determined by the theory of crystal growth are as follows,concentration of solution. agitation time,crystallization temperature and crystallization time.The results indicate that the optimal conditions of synthesizing intermediate are as follows,the mole ratio of acetone and acrylonitrile is 2.4,feed-in temperature 30～40℃, reaction temperature 50℃,reaction time 4h.The optimal conditions of withdrawing intermediate obtained by considering effects of crystallization factors are as follows,the amount of acetone for diluting(based on 0.5 mol acrylonitrile) 250mL,agitation time 1h. crystallization temperature 0℃,crystallization time 4h.The optimal conditions of neutralizing intermediate are as follows,the amount of toluene as solvent(based on 1g intermediate) 1.3mL,the intermediate is neutralized by ammonia as antacid assistant.After being neutralized,organic layer pH≈7.5. In the optimal technical process,the yield of intermediate is 58.8%based on acrylonitrile and the yield of DAAM was 49.6%based on acrylonitrile.The product are identified and analyzed by IR,GC and m.p.DAAM is obtained with purity of 99.76%,and melting point of 56.1～56.7℃.