Molecular Mobility of Unfilled and Carbon-Black-Filled Isoprene Rubber: Proton NMR Transverse Relaxation and Diffusion

Autor:	Ernst D. von Meerwall, T. Joshi, Ximei Sun, Avraam I. Isayev
Rok vydání:	2007
Předmět:	Polymers and Plastics Proton Diffusion Vulcanization Carbon black law.invention chemistry.chemical_compound chemistry Solid-state nuclear magnetic resonance Chemical engineering Natural rubber law visual_art Polymer chemistry Materials Chemistry visual_art.visual_art_medium Proton NMR Isoprene
Zdroj:	Rubber Chemistry and Technology. 80:854-872
ISSN:	1943-4804 0035-9475
DOI:	10.5254/1.3539421
Popis:	In an effort to understand the effect of ultrasound on the devulcanization of gum and filled isoprene rubber vulcanizates, solid state NMR 1H transverse relaxation (T2) was employed to analyze rubber molecular mobility. The T2 relaxation decay of the unfilled and the black filled IR was successfully described by a two-component model. The short T2 component arose from the chemically crosslinked (gel) and physically entangled (heavy sol) network. The long T2 decay came from the unentangled sol and dangling network chain ends. Vulcanization decreased the molecular mobility; however, ultrasound devulcanization partially reversed this effect. Addition of processing oil in the filled IR significantly altered the dependence of T2 on the sol fraction. T2 and pulsed-gradient diffusion experiments were carried out on IR melt specimens after sonication with or without subsequent vulcanization. The lowered and broadened M-distribution produced results quantitatively related to earlier work in natural rubber.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d19f1905b63ab88f83901b3de68842b8 https://doi.org/10.5254/1.3539421 Zobrazit plný text záznamu