Modification of rubber by iodoform

Abstract

The activity of iodoform (CHI 3 ) toward unsaturated rubbers was examined. Special attention was devoted to cis-1,4-(poly)isoprene (IR). The thermal decomposition of CHI 3 was studied by ion mass spectroscopy, and the obtained data were used for the identification of pyrolysis products of CHI 3 vulcanizates by pyrolytic gas chromatography. The kinetics of the chemical crosslinking of rubber were studied with a cure meter. The changes observed in the chemical structure of rubber were explained on the basis of 13 CNMR and Fourier transform infrared spectroscopy, differential scanning calorimetry, equilibrium swelling, and chemical microanalysis data. Apart from crosslinking, a simultaneous modification of the rubber macromolecules took place, specifically the cistrans isomerization of IR. This resulted in a significant increase in the rubber hardness, especially after a postheat treatment accompanied by oxidation. CHI 3 -IR vulcanizates behaved like thermoplastics because of the presence of a trans-1,4 phase, as confirmed by dynamic mechanical thermal analysis. The structure of the macromolecules treated with CHI 3 and its effect on the physical properties of the material were compared with those of peroxide-IR vulcanizates. The influence of the modification on the surface energy, bacteriostaticity, and mechanical properties of the vulcanizates was examined.

Morphological aspects of rubber fracture and wear

“…It is likely that the main type of agglomerates present and dominating character of filler–matrix interactions decide physical properties of the rubber sample, e.g., tensile strength, wear or dynamic dumping. Neither the degree of filler dispersion nor parameters of the fractal analysis of filler agglomerates investigated extensively by many authors,6–8 taking into account super‐aggregate/agglomerate organization, seem to be important. Calculated average values of fractal parameter ( D ), the most representative dimension of big CB agglomerates and average interparticle distance,9 have not reflected mechanical and tribological properties of the vulcanizates studied.…”

Application of ion bombardment to modify tribological properties of elastomers

“…Wettability of the materials surface before and after ion beam treatment was estimated from contact angle values, determined with a Krüss EasyDrop tensiometer (Germany), whereas changes to microhardness of the surface layer was determined by spherical nanoindentation (MML NanoTest 600, UK) [10]. Increase in microhardness can be subscribed to additional crosslinking of the elastomers studied [11].…”

Neutralization of Aerosolized Bio-Agents by Filled Nanocomposite Materials through Thermal and Chemical Inactivation Mechanisms

“…It is much less volatile and more stable at ambient conditions compared to elemental iodine. The sublimation of iodoform begins around 80 °C and the melting is reported to occur around 120 °C (Bieliński et al, 2007). When exposed to higher temperatures, iodoform starts to decompose around 160 °C, and major decomposition products include double-ionized iodine, iodine radical, and oxidation products of CHI 3 or iodine (e.g.…”

“…When exposed to higher temperatures, iodoform starts to decompose around 160 °C, and major decomposition products include double-ionized iodine, iodine radical, and oxidation products of CHI 3 or iodine (e.g. HIO 3 ) ( Bieliński et al, 2007). While Al-based composites using elemental iodine are best milled at liquid nitrogen temperature, so that iodine is solidified, this requirement may be less stringent for iodoform, and both room temperature and cryo-milling options can be explored for preparation of aluminum-based, iodine containing powders.…”