Evidence for Preferential Surface Enrichment in the Surface Chemical Analysis of a Series of Poly(Butyl Methacrylate-co-methyl methacrylate) Latices Using X-ray Photoelectron Spectroscopy and Static Secondary Ion Mass Spectrometry

Abstract

The surface chemical analysis of a series of poly(butyl methacrylate-co-methyl methacrylate) (MMA-BMA) latices, prepared by persulfate-initiated emulsion polymerization and characterized using standard colloid techniques, has been undertaken using X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The surface compositions of these latices were compared with the bulk polymer compositions and the surface compositions of solvent-cast (latex) polymer films. While the average particle size of the near-monodispersed colloids was found to be independent of composition, there was a marked increase in electrophoretic mobility and zeta potential values as the proportion of the BMA in the monomer mixture was increased. The XPS and SIMS analyses both revealed a higher level of MMA component of the copolymer in the latex films than would be anticipated from the bulk composition. In contrast, a significant enrichment of the BMA component of the copolymer was observed in the surface of solvent-cast films. These findings are briefly discussed where appropriate in terms of the particle formation mechanism, but in the main, this paper highlights their relevance to the study of surface chemistry of complex polymer colloids.

Desorption of Emulsifiers from Polystyrene Latexes Studied by Various Surface Techniques: A Comparison between XPS, ISS, and Static SIMS

“…More recent studies by XPS and static SIMS on poly(butyl methacrylate) latexes and copolymer latexes of poly(butyl methacrylate−methyl methacrylate) confirm the possiblity of obtaining qualitative and quantitative data for the components of the copolymer and polymer end groups at the surface of these colloids. Depending on the polymerization procedure, preferential surface enrichment of one monomer was detected.…”

Static secondary ion mass spectrometry (S-SIMS) Part 2: material science applications

“…A study on poly(butyl methacrylate) colloids allowed linkage of the mass spectral differences with the initiator concentration used (Davies et al, 1993a). Davies et al (1994) veri®ed the surface enrichment in a series of poly(butyl methacrylate-co-methyl methacrylate) (BMA-co-MMA) latexes, prepared by persulfate initiated emulsion polymerization. Fig.…”

“…The resulting polymers are, in general, Davies et al (1994) with the permission of the American Chemical Society.…”

Information on the Monomer Sequence of Poly(lactic acid) and Random Copolymers of Lactic Acid and Glycolic Acid by Examination of Static Secondary Ion Mass Spectrometry Ion Intensities

“…SSIMS has been used previously to examine the surface chemistry of random copolymers. Often, secondary ions specifically deriving from each of the comonomers can be identified and their intensities compared to provide an estimate of the near surface concentration of each component. − In some cases it is possible to detect secondary ions that result from two different comonomer units being adjacent to each other. , Lub et al . examined random copolymers of methyl methacrylate (MMA) and ethyl methacrylate (EMA) by SSIMS, and ions derived from MMA−MMA, EMA−MMA, and EMA−EMA diads within the copolymers were identified .…”