Effect Of Curing Medium On Surface Properties Of Ultraviolet Cured Acrylates And Its Application

Radiation curing had found an increasing success not only in traditional industry, but also in a variety of high-tech applications. For many applications the surface properties, such as wetting, adhesison, and coating characteristics are very important. As we all know that the surface properties not only depend on the chemical compositions, but also on the curing mediums and substrate. And we studied the surface properties of ultraviolet cured materials which cured in/on such different mediums as air, water, organic liquid and so on. By means of CA （contact angle） test, surface energy calculation and X-ray photoelectron spectroscopy, we analysised the characteristics of surface formation of the UV cured materials and their surface properties. The results showed that:The surface properties change phenomena can be affected by the curing mediums. It was found that the surface energy of the film cured in water is higher than that of cured in air, but the surface energy of films cured in organic liquid mediums （such as cyclohexane, Hexane）are far lower than that of cured in air.The results of XPS revealed that the movements of compositions were different when cured in different mediums, and the difference of surface properties rooted in the molecular migration and conformational change of the component. The components also affected the surface properties of cured film, however, the same component differ in their migration abilities when cured in different curing mediums.Furthermore, increasing the delay time elapsing between dope the mixtures and irradiation was varied could also affect water repellency properties of the cured films. And the results were different when cured in different curing mediums.Effects of curing medium on surface properties of cationic and radical-cationic Hybrid UV cured acrylates were similar to the radical cured acrylates: The surface energy of films cured in organic liquid mediums （such as cyclohexane, Hexane） was far lower than that of cured in air.In the end, we studied the technological application of the control of surface energy:We got the stain-resistant coating by adding the F-contained surfactants or the modified nano SiO₂. And it was also found that the higher hydrophobic surface was obtained by increasing the roughness of the hydrophobic film properly.By cured in different curing mediums successively, we also had made a surface heterogeneity film: some part of film’s surface was hydrophobic and the rest was hydrophilic.Molds were made from UV curing resins by the way of Solid Ground Curing （SGC） and the technology of the control of surface energy have been used to make hundreds of injection-molded parts out of plastic materials, such as polypropylene （PP）, polyethylene （PE） and nylon （PA66） with one tool.These results made it possible to design the polymer surface on the basis of the resin composition and on the coating conditions, while maintaining the bulk properties constant, they further confirmed the great flexibility of the UV-curing technique, making it suitable for interesting applications.