Kinetics of Disulphide–Disulphide Interchange Reactions in Polysulphide Polymers by Mass Spectrometry. I

Abstract

A novel analytical method using Electron Ionization Mass Spectrometry (EI/MS) was developed for studying the kinetics of disulphide–disulphide interchange reactions in polysulphide polymer blends. During the disulphide–disulphide interchange process, the concentration or reactants and products were measured from the observed peak heights of the respective dimer units. Reactions were studied in melt blends, over a temperature range of 207–220°C. An activation energy of 79.80 KJmol⁻¹ and pre-exponential factor log A=2.54 was observed. The dominant relaxation process for the intermolecular disulphide–disulphide interchange reaction in the polymer blend, without the influence of solvents and other reagents, is assumed to follow an associative mechanism. The model polysulphide polymers A (PS1) and B (PS2), used in this study, were formulated from bis (2-chloroethyl) ether and bis (2-chloroethoxy) methane, respectively.

Keywords:

• Disulphide
• Polysulphide
• Kinetics
• Mechanism Electron-ionization
• Mass spectrometry
• Disulphide–disulphide interchange

Acknowledgment

Preparation of this manuscript by Mary Becker is greatly appreciated.