Timeliness Analysis Of Medical Polymer Modification By Atmospheric Pressure Plasma Jet

Medical polymers have been used in the manufacture of artificial organs and medical instruments because of their good mechanical properties,functional properties and good biocompatibility.However,the high Vander Waals force between polymer molecules leads to its poor hydrophilicity,which affects its blood compatibility after implantation or application.Therefore,the hydrophilic modification of polymers has been a hot topic in recent years.Plasma modification,as one of the polymer modification methods,is widely favored because of its high efficiency.However,it has become a new problem that which parameters are used to modify the polymer and which preservation means are used to maintain the polymer's hydrophilicity to the greatest extent.The main work of this paper is as follows:Plasma jet treatment with mixed water was used as a method of polymer modification.The optimal discharge parameters are determined as follows: the working gas is pure nitrogen,the discharge form is bare metal electrode discharge,and the voltage is stabilized at U= 1.8k V.The mixed water plasma jet was prepared by a self-made mixing device,and the mixing water ratio was controlled at 0%~2%.The generated jet has a stable length and is suitable for modification.In order to study the influence of different water mixing ratio plasma jet on polymer modification effect and hydrophilic timeliness,polyether ether ketone and polyethylene were treated by plasma jet with different water mixing ratio(MR is 0%,1% and 2%,respectively),and their modification effect and hydrophilic stability were compared through comparative tests.The experimental results show that the hydrophilic stability is different after the modification of plasma jet with different proportion of mixed water.Plasma jet with 1% water mixing ratio has the best hydrophilic modification effect and is the most stable.After determining the proportion of mixed water,the optimal storage environment can make the polymer's hydrophilic rebound the least through comparative test,so that the modified polymer has the best hydrophilic time efficiency.The polymer was placed in room temperature air,low temperature air,water,room temperature vacuum,low temperature vacuum and other environments,and the hydrophilicity was observed by measuring the contact Angle between them.The results show that the low temperature and vacuum environment is beneficial to maintaining the hydrophilicity of the polymer.The modified polymer was placed in the saliva environment for 40 days,and its hydrophilicity was observed.It was found that the polymer modified by mixed water plasma could still maintain a certain hydrophilic time-efficiency when placed in the saliva.