Microstructures of Butadiene Copolymers Determined by Ozonolysis/MALDI Mass Spectrometry

Abstract

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry of ozonolysis degradation products was used to determine the microstructures of several butadiene copolymers. A random styrene−butadiene copolymer containing 45 wt % styrene was distinguished from a block (ABA) styrene−butadiene copolymer containing 38 wt % styrene. In addition, several acrylonitrile−butadiene copolymers with acrylonitrile contents ranging from 21 to 51 wt % were analyzed. The microstructures for the acrylonitrile−butadiene copolymers were confirmed to be fairly random. Quantitatively, the acrylonitrile compositions determined by ozonolysis/MALDI-MS were close to the reported values for these copolymers (typically within 5 wt %). The discrepancy between the reported and experimentally obtained compositions may be attributed, in part, to a composition bias arising from the ozonolysis process. A simple model for ozonolysis of a random copolymer was developed to investigate the effects of ozone exposure time on the oligomer distributions observed in the MALDI mass spectra.

Household Ozone Disinfector as An Alternative Ozone Generator for Ozonolysis of Alkenes

“…Furthermore, this equipment should not only be beneficial for the organic synthesis community but also for other research areas. For example; the use of ozonolysis to determine the olefinic position on the synthetic polybutadiene rubber [40] and natural products such as fatty acid, [41] phospholipid, [42] alkaloids and coumarins [43] or the study on biomass conversion or degradation of renewable feedstock by ozonolysis. [44] Currently, demonstration of ozonolysis in an undergraduate laboratory class using household ozone disinfector is carrying out and will be reported in due course.…”

The chemomechanical properties of microbial polyhydroxyalkanoates

“…Additional assessment techniques may be of benefit. MALDI-TOF analysis of partially hydrolyzed PHA could also be used to distinguish blocky from random copolymers [407]. MALDI-TOF analysis of partially hydrolyzed PHA could also be used to distinguish blocky from random copolymers [407].…”

Preliminary Silylation for Structure Determination of Oligomeric Silsesquioxanes by Matrix-Assisted Laser Desorption/Ionisation Mass Spectrometry

“…8 ozonolysis followed by reductive cleavage of ozonides was efficiently used for the study of unsaturated polymers. 9 Simple derivatisation, widely used in gas chromatography/ mass spectrometry (Gc/MS) (silylation, acylation, alkylation of functional groups), has rarely been applied to the analysis of polymers and oligomers by soft-ionisation mass spectrometry. Nevertheless, a study should be mentioned 10 where silylation, methylation and anthrylmethylation were tested in order to improve the cationisation of poly(acrylic acid) under MALDI conditions.…”