Research On Improvement Of Adhesive Property Of Polymers By Atmospheric Pressure Plasma Jets

In order to solve the problem of weak adhesion of polymer materials,atmospheric pressure plasma jets(APPJs)were used to treat the polymer surface to improve its adhesive property.Starting from the APPJs generator,the effect and mechanism of three types of APPJs on improving the adhesive property of typical polymer polyethylene(PE)were studied.The adhesive property improvement test was carried out by using APPJs array.The main research contents are as follows:In order to use APPJs to improve the adhesive property of polymers,a set of APPJs generator was built by ourselves.Bare electrodes APPJs and cross-field and parallel-field dielectric barrier APPJs were generated by different electrodes.The effects of discharge voltage and gas flow rate on the discharge of the three types of APPJs were investigated respectively,thus the discharge parameters suitable for polymer treatment were determined,and the characteristics of jets under the parameters were analyzed.In order to explore the effect and mechanism of different types of APPJs on improving the adhesive property of polymers,three types of APPJs were used to carry out surface treatment experiments with PE as a typical polymer.The water contact angle(WCA)of the treated PE surface was measured respectively to characterize the hydrophilicity of the PE surface.Scanning electron microscope(SEM)and X-ray photoelectron spectroscopy(XPS)were used to analyze the reasons for the change of hydrophilicity.The results showed that the WCA of the PE surface treated by the three types of APPJs will be obviously reduced and will remain unchanged at last,that is,the hydrophilicity will be improved.SEM photos of PE surface treated by bare electrode APPJs showed no obvious change,but the surface treated by dielectric barrier APPJs showed obvious pit microstructure,increased surface roughness and faster parallel field etching rate.All three APPJs can improve the oxygen content and reduce the carbon content of the treated surface,and introduce new oxygen-containing active functional groups.PE adhesive test results showed that three kinds of APPJs can improve their adhesive properties,but the parallel field APPJs had the best effect.The adhesive test of polytetrafluoroethylene(PTFE)under the same parameters proved that APPJs can also effectively improve its adhesive performance.In order to improve the processing efficiency,a bare electrode and parallel-field APPJs array dual-use large-area plasma jet generator was fabricated.Then,the adhesive performance improvement tests of PE were carried out using the two APPJs arrays respectively.The results showed that compared with a single jet of the same type,the jet array can greatly improve the processing efficiency and the adhesive strength can be greatly improved.