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Detailed structural analysis of diblock copolymers by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Author(s) -
WilczekVera Grazyna,
Yu Yisong,
Waddell Keith,
Danis Paul. O.,
Eisenberg Adi
Publication year - 1999
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/(sici)1097-0231(19990515)13:9<764::aid-rcm557>3.0.co;2-9
Subject(s) - copolymer , chemistry , mass spectrometry , polymer , desorption , monomer , polymerization , depolymerization , polymer chemistry , ionization , degree of polymerization , styrene , analytical chemistry (journal) , organic chemistry , chromatography , ion , adsorption
The individual block length distributions of poly(α‐methylstyrene)‐b‐poly(4‐vinylpyridine) diblock copolymers have been determined by the MAC MALDI‐TOFMS method of analysis of copolymers, which combines matrix assisted laser desorption/ionization time‐of‐flight mass spectrometry with computational data treatment. The problem of the possibility of multiple assignments of chemical composition to the mass spectral peaks is discussed in detail. A solution based on the pattern of peak clusters is proposed and verified using the statistical random coupling hypothesis test. The progress of the anionic polymerization in a series of polymers prepared by sequential addition of the second monomer to a living chain system is studied and shown in three‐dimensional (3‐D) plots of experimental individual blocks length distributions. The presence of unreacted homopolymer has been observed as well as bimodal and trimodal distributions for the poly(α‐methylstyrene) and the poly(4‐vinylpyridine) segments. A depolymerization process of the homopoly(α‐methylstyrene) in the series of poly(α‐methyl‐styrene)‐b‐poly(4‐vinylpyridine) diblock copolymers was detected following a temperature rise. It was confirmed that it is impossible to place a single unit of 4VP at the end of each PαMS chain. Copyright © 1999 John Wiley & Sons, Ltd.