title: Determination of Block Length Distributions of Poly(oxypropylene) and Poly(oxyethylene) Block Copolymers by MALDI-FTICR Mass Spectrometry.
abstract: Matrix-assisted laser desorption/ionization (MALDI) was performed on an external ion source Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS) to analyze the block length distributions of triblock polymers of poly(oxypropylene) and poly(oxyethylene). The first series of results presented demonstrate that the apparent molecular weight distributions are distorted. This distortion is induced by the flight-time-induced mass discrimination inherent in the experimental technique, the variation of isotopic patterns over the measured mass range, and the overlap of peaks in the spectrum. Subsequently, a method for the treatment of molecular weight distributions measured by MALDI on an external ion source FTICR-MS is developed to yield the actual molecular weight distribution and, from that, the individual block length distributions. For the first time, detailed and accurate molecular weight data were obtained on a complex sample using this methodology, which independently validates the data provided by the manufacturer. The experimentally verified random coupling hypothesis proves the validity of the methodology.
authors.affiliation: FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands.
authors.forename: G J
authors.initials: GJ
authors.lastname: van Rooij
authors.forename: M C
authors.initials: MC
authors.lastname: Duursma
authors.forename: C G
authors.initials: CG
authors.lastname: de Koster
authors.forename: R M
authors.initials: RM
authors.lastname: Heeren
authors.forename: J J
authors.initials: JJ
authors.lastname: Boon
authors.forename: P J
authors.initials: PJ
authors.lastname: Schuyl
authors.forename: E R
authors.initials: ER
authors.lastname: van der Hage