Secondary Molecular Mobility in Amorphous Ethyl Cellulose: Aging Effects and Degree of Co-Operativity

被引：13

作者：

Diogo, Herminio P. ^{[3
]}

Moura-Ramos, Joaquim J. ^{[1
,2
]}

机构：

[1] Univ Tecn Lisboa, Ctr Quim Fis Mol, P-1049001 Lisbon, Portugal

[2] Univ Tecn Lisboa, Inst Super Tecn, IN Inst Nanasci & Nanotechnol, P-1049001 Lisbon, Portugal

[3] Univ Tecn Lisboa, Ctr Quim Estrutural, IST, P-1049001 Lisbon, Portugal

来源：

JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS | 2009年 / 47卷 / 08期

关键词：

aging; amorphous; beta-relaxation; dielectric properties; Johari-Goldstein; polysac-charides; relaxation; secondary relaxation; thermally stimulated currents; DIELECTRIC-RELAXATION PROCESSES; THERMALLY STIMULATED CURRENT; GLASS-TRANSITION; BETA-RELAXATION; POLYSACCHARIDES; SPECTROSCOPY; TEMPERATURE; CREEP; TSDC; FRAGILITY;

D O I：

10.1002/polb.21688

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The secondary relaxations in amorphous ethyl cellulose are studied using thermally stimulated depolarization currents (TSDCs) in the temperature region from 165 degrees C (108 K) up to 145 degrees C (418 K). The influence of aging on the current peaks of the secondary relaxation is discussed, and it is concluded that some modes of motion of this mobility are aging independent, while others are affected by aging. A particular attention is focused on the discussion of the degree of co-operativity of the motional modes of the secondary relaxation. The conclusion to be driven from the obtained TSDC results is that the aging-independent motional modes, as well as those that are aging dependent, do not show any appreciable co-operative character. (C) 2009 Wiley Perodicals, Inc. J Polym Sci Par-t B: Polym Phys 47: 820-829, 2009

引用

页码：820 / 829

页数：10

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