Abstract
Surface hardness of PMMA (poly methyl methacrylate) was improved by low energy nitrogen ion irradiation. It was confirmed that hardness on the surface was improved by increasing the acceleration voltage of ion irradiation. It was thought that this was because the projected range became long and region of cross-link formation became thick. However the depth of cross-link formation was not confirmed. Then, distribution of the cross-link structure in the direction of depth was measured by using XPS (X-ray Photoelectron Spectrometer).
As a result, it was confirmed that the surface hardness was improved on the formation depth of the C-N-C bonds. From this, it was suggested that the modification layer of the cross-link structure became thick the surface hardness became strong.
