Reaction of Deuterated Polystyrenes with Hydrogen and Deuterium Atoms

Abstract

Investigation of the electron spin resonance spectra shown by finely divided polystyrene and selectively deuterated polystyrenes, upon exposure either to hydrogen atoms or to deuterium atoms, demonstrates that the predominant reaction is the addition of a hydrogen atom to the phenyl ring, thus producing a cyclohexadienyl-type radical. The specific rate of this reaction at room temperature is estimated to be 4×103 liters mole—1·sec—1; the specific rate at which hydrogen atoms react with the cyclohexadienyl-type radical is estimated to be 106 liters mole—1·sec—1. The rate at which iodine vapor reacts with the cyclohexadienyl radicals is probably about the same value. Qualitatively, the results produce an insight into the mechanism of the radiolysis of polystyrene. It seems evident that although the mechanism is complex, both the evolved hydrogen and the crosslinking seen in the irradiation of polystyrene occur by means of radical precursors.

ESR Spectroscopy in Polymer Research

“…ESR spectra of different substituted deuterated polystyrenes have been discussed in a few other papers 702,704,1001,2382).…”

“…During the reaction of atomic hydrogen with different organic compounds 421 , 465, 1961,1962), synthetic polymers144, 574,575,579,582,583,1001,2182,2376,2377,2381,6. ESR Study of Polymers in Reactive Gases 2382) and biopolymers 930 .…”

Reactions of alcohols adsorbed on MgO. Part I. Heterogeneous reactions with hydrogen atoms and trapped electrons at room temperature: a new technique in surface chemistry

“…(23). The hydroxyl proton must be nearby and chemisorption probably occurs according to the schematic reaction [2]. Presumably, most of the first monolayer becomes chemisorbed.…”

“…After pumping for 30 min, only a quarter as many radicals were formed. A small fraction of the first monolayer of ethanol must be very strongly physisorbed or has become bonded to the surface by a reaction analogous to [2]. The stable radical (Fig.…”

“…Solids investigated at room temperature are polymer "fl~luffs" (1,2), suspensions on quartz wool (3, or pure finely divided powders (4)(5)(6)(7); some compounds which are liquid at room temperature have been bombarded with atoms in the frozen state (8)(9)(10). Heterogeneous reactions with adsorbed molecules have been very few.…”