Hydrogenation and neutralization of carboxylic styrene–butadiene latex to form thermoplastic elastomer with excellent thermooxidation resistance

Abstract

Hydrogenation of carboxylic styrene-butadiene rubber latex was carried out using hydrazine and hydrogen peroxide with ferrous sulfate as a catalyst without pressurized hydrogen and an organic solvent. A mixed inhibitor was used during hydrogenation to prevent gel formation. Various hydrogenation conditions were studied. Ferrous sulfate is better than is cupric sulfate as a catalyst. The hydrogenation degree can reach over 90%. The hydrogenated product was characterized by IR and DSC. The hydrogenated products behave as a thermoplastic elastomer with excellent thermooxidation resistance, due to the absence of most double bonds and the presence of crystalline domains of polyethylene segments formed by the hydrogenation of polybutadiene segments. Ionomers were obtained by neutralization of the hydrogenated product with metallic ions and characterized by IR, DSC, and TEM. The ionomers also behave as thermoplastic elastomers with mechanical properties better than those of the hydrogenated product without neutralization, due to the existence of ionic domains besides the crystalline domains.

Improving thermal and ozone stability of skim natural rubber by diimide reduction

“…On the other hand, the hydrogenation degree decreased when [N 2 H 4 ] was higher than 2.68 M. This phenomenon can be explained in that the diimide species can self-react at high diimide concentration to cause a decrease in hydrogenation efficiency (HE). Another possible explanation for the lower hydrogenation efficiency is that the excess diimide in this system may diffuse into the aqueous phase [14].…”

Development of amino resins for emulsion paint formulation: effect of aldelhydic group and degree of substitution

“…However, elongation at break for mono and di ethylol urea was determined and the results were 125 and 60% respectively. These observed behavior of the different resins from different aldehydic groups and those from the same aldehydic group can be explained on the basic of differentials in molecular weight, crytallinity, crystalline orientation and general molecular features (Xie et al, 2001;Chain and Yi, 2001;Wang and Gen, 2002). Table 4 compares some physical properties of mono ethylol urea resin with films from some other convectional paint binder.…”

Preparation of a Polyethylene Latex by Catalytic Hydrogenation of a Polybuta‐1,4‐diene‐Based Dispersion

“…Since this early effort, a number of studies have been published in this area, but all of them mainly focus on enhancing the properties of latexes based on acrylonitrile-butadiene [6][7][8][9][10][11] and styrene-butadiene rubbers. [12][13][14][15] Until now, no group has taken advantage of the hydrogenation reaction to generate polyethylene (PE) latex. Such a route is potentially of great interest to produce a purely linear PE-based latex with very different properties from those of branched PEs produced by free radical emulsion polymerization.…”