Open AccessEvaluation of matrix-assisted laser desorption ionization mass spectrometry for studying the sec-butyllithium and n-butyllithium initiated ring-opening polymerization of hexamethylcyclotrisiloxane (D3)
Author(s) -
Adam M. Hawkridge,
Joseph A. Gardella
Publication year - 2003
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1016/s1044-0305(02)00806-1
Subject(s) - chemistry , mass spectrometry , polymerization , butyllithium , solvent , ionization , anionic addition polymerization , desorption , analytical chemistry (journal) , photochemistry , polymer chemistry , organic chemistry , chromatography , polymer , ion , adsorption
Matrix assisted laser desorption ionization (MALDI) was used to study the organolithium initiated ring-opening polymerization of hexamethylcyclotrisiloxane (D3) in a mixed solvent system. The mass spectral peak intensities were monitored to determine the effects of polymerization time, initiator concentration, and reaction temperature on the formation of the mono, di, and trisiloxanolate initiator species and the extent of chain redistribution. The three initiator species were formed by reacting n-butyllithium and sec-butyllithium with D3 in nonpolar solvent. The mass spectral results showed that sec-butyllithium and n-butyllithium form different populations of initiator species under the same conditions and that the measured mass spectral peak intensities do not accurately represent the population of siloxanolate initiator species prior to propagation. The changes in peak intensities were attributed to chain redistribution.