Study On Plasma Surface Modification Of Polymethyl Methacrylate For Antistatic Property

Polymer materials are wildly used because of beautiful appearance, low cost, high insulation, processing ease and excellent chemical inert. However, static electricity can be easily built up by friction of two polymer materials. This can lead to a number of problems, such as accumulation of dust, close of thin-film integrated circuit, breakthrough of electronics parts, electroshock and explosion. To minimize these hazards, the surface resistivity of materials will be generally limited below 10¹²Î©/sq. in the industry. The most practicable solution is using an antistatic additive or reagent by attracting water from the environment to lower the surface resistivity of polymer, but antistatic reagents that were conventionally composed of surfactants of a low molecular weight do not produce a durable effect because the antistatic layer can easily be removed. The use of carbon black and metal fillers can improve the antistatic property permanently, but this solution has many shortcomings in term of high cost, not easy coloration, poor stability and decreasing physical property. Therefore, surface modification is becoming an important solution to improve the antistatic property of polymer materials. In this paper, the antistatic property of polymethyl methacrylate (PMMA) surface was improved by plasma treatment.(1) The PMMA surface was modified by argon (Ar) plasma treatment and effects of plasma treatment time, Ar pressure and discharge power on hydrophilicity of PMMA surface were investigated. The antistatic property of polymers can be measured in terms of their surface resistivity. The contact angle measurement showed that the hydrophilicity of PMMA surface was improved greatly and the contact angle against water decreased from 80.4 ° to 47 °at optimum conditions: treatment time = 3 min, Ar pressure = 50 Pa and power = 40 W. The results of surface resistivity measurement showed that there was no distinct improvement for antistatic property despite great improvement for hydrophilicity of PMMA surface.(2) The PMMA surface was pretreated by plasma discharge to improve its hydrophilicity, and then PEG-200 was immobilized onto the surface of PMMA by Ar plasma-induced reaction. Effects of PEG-200 concentration, plasma immobilization time, Ar pressure and discharge power on the hydrophilicity and surface resistivity on...