| Novel polymeric materials are characterized by time-of-flight secondary ion mass spectrometry (TOF-SIMS), matrix-assisted laser desorption mass spectrometry (MALDI-MS), and x-ray photoelectron spectroscopy (XPS). In addition to giving insight into the polymerization processes, the results provide the basis for comparing, evaluating, developing the capabilities of the named analytical techniques.; With TOF-SIMS, characteristic fragment signals in the low mass region ({dollar}<{dollar}500 Da) and intact oligomers in the high mass region (500-10,000 Da) are identified and evaluated. {dollar}rm Msb{lcub}n{rcub}{dollar} values are calculated using intact oligomers. Fragment signals (endgroup/polymer ion ratio) are also used to determine {dollar}rm Msb{lcub}n{rcub}{dollar} for polystyrene (PS), through the generation of a calibration curve. The quantification of endgroup functionalization by TOF-SIMS is investigated using intact oligomer signals from a model PS system. Quantification is shown to be possible only after the relative signal intensities of functionalized and unfunctionalized oligomers have been determined. Desorption and ionization processes are probed using novel sample preparation methods and by employing multiphoton ionization sputtered neutral mass spectrometry (MPI-SNMS). TOF-SIMS is also employed to follow polymerization processes and evaluate polymerization mechanisms. Three examples are shown, specifically for the synthesis of polydimethylsiloxane and poly(arylene ether ketone), and the hydrogenation of polybutadiene.; A standard protocol for the preparation of polymeric samples for MALDI-MS analysis is given. Polymers up to 49 kDa are analyzed with {dollar}rm Msb{lcub}n{rcub}{dollar} in good agreement with gel permeation chromatography (GPC). Variation in laser intensity is demonstrated to influence the molecular weight distribution of intact oligomers, most significantly for low molecular weight polymer. The capabilities of the linear and reflectron analyzer mode are also compared. Furthermore, using MALDI-MS, the endgroup composition of PS is demonstrated not to have a significant effect on the ion yield.; Both XPS and TOF-SIMS are used to evaluate a block copolymer with PS and teflon-like blocks. Factors such as PS chain length, annealing, and film thickness are varied to investigate their effect on the surface composition (or the extent of surface segregation) of the film. The results allow comparison and evaluation of the sampling depths and sensitivity ofthe two techniques. |
