Characterization of Polymerization Reagents Incorporated into Poly(methyl methacrylate) Chains by Pyrolysis-Gas Chromatography

Abstract

ABSTRACT:High-resolution pyrolysis~gas chromatography was successfully applied to characterize the end groups of poly(methyl methacrylate) (PMMA) prepared by radical polymerization. Although PMMA mainly depolymerized to the monomer at elevated temperatures, some of the minor peaks on the pyrograms could be assigned to the products associated with the end groups derived from both the initiation reactions caused by benzoyl peroxide (BP0) and the chain transfer reactions to dodecanethiol and solvent. Two kinds of BP0-initiated chain ends were clearly distinguished. It was confirmed that phenyl-initiated polymer chains rather than benzoyloxyinitiated ones were prefeTentially formed in solution polymerization, whereas the latter predominated in bulk polymerization. Moreover, the characteristic peak intensities could be correlated to the amounts of polymerization reagents in the feed. In addition, dodecanethiol formed from thiol-incorporating chain ends was selectively detected without interference from any other pyrolysis products by using a sulfur-specific flame photometric detector.

Characterization of End Groups in Polycarbonates by Reactive Pyrolysis-Gas Chromatography

“…In SEC measurements, the relationship between [11] and M of different polymers eluting at the same retention volume is given by (2) where [11] …”

Complementary Characterization of End Groups in Radically Polymerized Poly(methyl methacrylate) by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry and Pyrolysis-Gas Chromatography-Mass Spectrometry

“…7,8) In addition, Py-GC-MS (or Py-GC with other detection methods) was also applied for the highly sensitive analysis of end groups in various PMMA samples, including the quantitative determination. [9][10][11][12][13][14] To the best of our knowledge, this work is the rst report on the complementary use of both MALDI-MS and Py-GC-MS to characterize end groups in polymer sample. In particular, a high-resolution spiral time-of-ight (TOF) analyzer was used for MALDI-MS to con rm m/z for the key components precisely in this work.…”

Evidence on unusual way of cocaine smuggling: Cocaine-polymethyl methacrylate (PMMA) solid solution—study of clandestine laboratory samples

“…3) the main pyrolysis product of PMMA reference material was identified as methyl methacrylate monomer (MMA). Such a result was expected, since PMMA tends to depolymerise mostly (>90%) into an original monomer at the temperatures above 500 8C [18]. GC-MS analyses of liquid samples enabled us to separate and identify cocaine and gasoline or benzine (see Fig.…”