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Cf-252 particle (plasma) desorption mass spectra are presented for polystyrene surfaces before and after exposure in air to UV light. The photooxidation produces changes observed in both positive and negative ion spectra.Oxygen incorporation produces a slight increase in intensity of m/z' 18 and 19 (HzO' and H,O') and m/z-16 and 17 (0-and OH-). Also, the relative intensity of m/z' 91 decrenses after photooxidation and is interpreted as the formation of a bond alpha to the benzene ring. New peaks are detected at m/z' 226, 227 and 331, and are tentatively assigned to hydroperoxide-containing structures. Other changes in the spectrum include the increase in intensity of m/z' 77 and 105 arising from easily ionized fragments of the oxidation products of polystyrene.

Cf-252 particle desorption mass spectrometry (PDMS) has been applied to a series of industrial polymers. PDMS is a surface technique suited for analysis of polymers since 105 fission fragments impinging on the target are sufficient to obtain a mass spectrum, thus minimizing surface damage and charge-up. Positive and negative ion spectra with masses up to m/z 400 amu were obtained for the following samples: polystyrene, poly(alpha methylstyrene), poly(ethylene terephthalate), poly(methyl methacrylate), and poly(butyl methacrylate). Polymers were studied in the form of solvent recuperated films or as self-standing films. The mass spectra of positive and negative ions showed masses corresponding to different sized monomer fragments. For each polymer, its spectrum can be used as a fingerprint. The mass spectra were compared to those obtained by other mass spectrometric techniques.

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