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Plasma-Induced Modifications on High Density Polyethylene and Polyethylene Terephthalate


 This work presents a comprehensive study of high-density polyethylene (HDPE) and polyethylene terephthalate (PET) surface properties after exposure to 1.5, 3, 4.5, and 6 min oxygen (O2) plasma. The polymer surface structure was analyzed by Raman spectroscopy, which revealed surface restructuring modifications. The contact angle of HDPE and PET decreased gradually, and the work of adhesion was improved with O2 plasma. The water contact angle was reduced from 61.6o to 36.3° for HDPE and from 72.4o to 37.5° for PET by increasing plasma time from 1.5 to 6 min. The surface free energy is enhanced from 27.8 to 69.0 mJ/m2 for HDPE and from 29.8 to 67.2 mJ/m2 for PET, when the plasma time increased from 0 to 6 min. The polar groups significantly reduced the hydrophobicity of the irradiated films, and consequently the surface wettability was improved. The results show observed improvement in surface properties of HDPE and PET polymeric films to be use in different applications such as printings, coatings, and optoelectronics