EFFECT OF HYDROGEN BOND FORMATION ON PHYSICAL AGING OF ETHYLENE-VINYL ALCOHOL COPOLYMERS WITH ANNEALING BELOW Tg

Autor:	Naoto Takemura, Hirohisa Yoshida, Hajime Kanbara, Yasuji Kobayashi
Rok vydání:	1983
Předmět:	chemistry.chemical_compound Crystallinity Materials science Physical aging chemistry Hydrogen bond Annealing (metallurgy) Enthalpy Copolymer Modulus Physical chemistry Alcohol General Medicine
Zdroj:	Sen'i Gakkaishi. 39:T512-T518
ISSN:	1884-2259 0037-9875
DOI:	10.2115/fiber.39.12_t512
Popis:	The changes of the mechanical properties of poly (ethylene-co-vinyl alcohol) (EVA) with annealing below Tg were studied. EVA samples obtained by quenching from the molten state, having 11-17% of crystallinity, were annealed at (Tg-10°C) for 4-160 hrs. From the stress-strain curves of the original and the annealed samples, yield strain (ey), yield stress (σy) and Young's modulus (E) were obtained. The changes of ey with annealing depends on the VA content. σy, and E of all samples increased with the annealing. The changes of E with annealing were discussed by assuming the first-order process. The higher the VA content, i.e., the richer the hydrogen bonding, the slower the rate of E change with annealing. This result agreed with the fact that the enthalpy relaxation was restricted by the hydrogen bond formation.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fbf712e10b9747debad5e760924b228b https://doi.org/10.2115/fiber.39.12_t512 Zobrazit plný text záznamu