No abstract

No abstract

This paper presents the application of static time-of-flight secondary ion mass spectrometry (ToF-SIMS) to the analysis of polymeric materials, including chemically modified polymers and polymer additives. Through the detection of intact functionalized oligomers, analysis of poly(styrene) functionalized with perfluoroalkyl chlorosilane provides confirmation of a successful endgroup termination for a living polymerization. The calculated molecular weight distribution also is in good agreement with chromatographic results. High mass resolution studies allow monitoring of the hydrogenation of a poly(butadiene) polymer through increases in oligomer mass due to proton addition. The quantitative ToF-SIMS results for the extent of hydrogenation for a specific oligomer are lower than the values averaged over all oligomers as determined by magnetic resonance. The usefulness of ToF-SIMS for determination of trace-level polymer additives is demonstrated for linear low-density poly(ethy1ene) (LLDPE). Application of a 150 nm thick evaporated Ag pattern enables in situ detection of the five trace additives present in the LLDPE matrix, and also provides information on additive surface migration and surface oxidation. A study of the silver cationization process for the silver-patterned LLDPE surface suggests differences in diffusion and/or ionization processes for two additives. This is confirmed with mass-resolved ion imaging to show the lateral distribution of the silvercationized signals for various polymer additive molecular ions. Finally, poly(styrene) (M,, = 1300) coated with a continuous silver overlayer is investigated. The ToF-SIMSdetermined molecular weight distribution shifts to lower masses, suggesting the greater diffusion of shorter polymer chains through the silver overlayer.

The applicability of time-of-flight secondary ion mass spectrometry (TOF-SIMS) for quantification of functionalization is demonstrated using five 1.0 X103 g/mol polystyrene samples which were synthesized by living anionic polymerization. The polymerizations were functionally terminated to various extents (0,25,50,75, and 100%) by using sequential termination techniques with chlorodimethylphenylsilane and methanol. Two distinct molecular weight distributions of intact oligomer signals are resolved in the TOF-SIMS spectra resulting from the functionalized and unfunctionalized (protonated) oligomer species in each sample. Through direct comparison of the signal intensities of the two types of oligomers, the extent of functionalization is determined at each degree of polymerization and agrees well with expected values. The results are substantiated using physical mixtures of dimethylphenylsilyl (100% functionalized) and proton (0% functionalized) terminated polymers. The relative oligomer intensities for the physical mixture of polymers corresponds well to the ratio in which they were initially combined. Sputter yield, extent of fragmentation, and ionization and detection probabilities are determined to be very similar for the protonand dimethylphenylsilyl-functionalized oligomers. Thus, quantification of endgroups can be achieved without standards calibration. Analysis by gel permeation chromatography (GPC) shows a systematic shift to higher (Md) values as the extent of functionalization of the polystyrene samples is increased from 0 to 100%. (M") values calculated from TOF-SIMS analysis for the oligomers agree well with GPC results. The

Ionic liquids bolster the conductivity of hybrid composite polymer electrolytes based on poly(ethylene glycols) and organic–inorganic silica nanoparticles formed in situ.