XPS ANALYSIS OF POLY[(3-HYDROXYBUTYRIC ACID)-CO-(3-HYDROXYVALERIC ACID)] FILM SURFACES EXPOSED TO AN ALLYLAMINE LOW-PRESSURE PLASMA

Homogeneous and stable layers were deposited through allylamine plasma polymerization (75 W, 100 Pa, 15 min) onto poly[(3-hydroxybutyric aci d)-co-(3-hydroxyvaleric acid)] (91:9 wt.-%) (P(HB-co-9%HV)) film surfa ces. XPS analysis using take-off angles of 20 degrees and 70 degrees a nd performed 10 days and 20 days after plasma treatment gives informat ion on the composition (in atom %) of the modified surface: C, 62.74; N, 19.60; O, 17.65. The unexpected oxygen percentage is weaker if argo n plasma pretreatment (25 W, 40 Pa, 5 min) is applied. Then, a succinc t mechanism is proposed. The study of changes in element ratios and bi nding energy values shows that the majority of incorporated functional groups seem to be amide and imine groups.