Atmospheric Plasma Surface Modification of PMMA and PP Micro‐Particles

Chemical surface modification of polymethylmethacrylate (PMMA) and polypropylene (PP) particles was achieved using a continuous atmospheric plasma process, resulting in increased oxidation and hydrophilicity. Contact angles of treated PMMA ranged from 79-117 degrees (125 degrees for untreated). Air plasma produced higher contact angles than pure nitrogen, which is attributed to primary surface degradation from oxygen. Higher energy and flow rate of water resulted in decreased contact angles. Treated PP mixed in water upon agitation, while untreated PP remained at the surface. X-ray photoelectron spectroscopy (XPS) showed increased C-O and C=O for treated samples. The addition of 10% hydroxyethylmethacrylate (HEMA) to water showed a slight decrease in contact angle, but no difference from pure water in XPS results.