Synthesis And Properties Of UV-curable And Degradation Coating Resin

The development of polymer preferred to resource-saving and environmentalfriendly materials in the future. According with this trend, using maleic anhydride,phthalic anhydride, sebacic acid, ethylene glycol, propylene glycol, polyethyleneglycol-400and urea, a new unsaturated polyester-urea amide oligomer which showedsuperior performance in UV curing and degradation was synthesized by direct meltpolymerization in this paper. Because of good properties of self-initiated and watersolution, unsaturated polyester-urea amide is less harm to human health andenvironment than traditional UV-curable oligomer. So it is useful to disposableproducts and food packaging.In this paper, property of polymerization, physical properties of product, UVcuring, water solution and degradation of oligomer were studied. All results showthat:(1) The descending rate of the acid value of the reaction is slown down with thetime passing. Increasing the use of sebacic acid and urea is helpful to the speed ofpolymerization. But to avoid the speed of reaction out of control, the dosage of ureaneeds to plan.(2) The molecular weight of the oligomer over2000. The oligomer has goodfluidity in80℃and bad in25℃. The oligomer shows yellow and the color is deeperas the increase of urea dosage. Keep the product for a long time, some inhibitor isneeded and sun light, water, high temperature should be avoided.(3) The oligomer shows obviously self-initiated behaviors in UV curing. It canbe cured in30～60s without photo-initiator. Increasing the use of urea is helpful tocuring speed, while the curing speed is slown down as the urea dosage up to a certaindegree.When the mole fraction of urea in raw material was0.04～0.05, the oligomerhas better curing speed with self-initiated. But its gel content is less than the oligomerused photo-initiator. So this oligomer is unfit for other UV curing system as a microinitiator.(4) When the mole fraction of urea in raw material is more than0.04, the oligomercan be dissolved directly. When the mole fraction of urea is0.04～0.05, the mole ratioof saturated acid and unsaturated acid is1:7～1:9, the mole fraction of polyethyleneglycol-400in alcohol component is0.15, mixture of D-1173and benzophenone asphoto-initiator with the amount of3wt%～4wt%, the comprehensive properties ofthe product are the best. (5) Increasing the use of polyethylene glycol-400and urea is helpful to thehydrophilicity of oligomer. In order to ensure sufficient UV-curing properties, theirdosage is limited to a certain degree. When the mole ratio of saturated acid andunsaturated acid is1:7, the mole ratio of phthalic anhydride and sebacic acid is1:1.1,the product shows good properties of UV curing and degradation at the same time.