Mechanism of degradation induced embrittlement in polyethylene

被引：142

作者：

Fayolle, B. ^{[1
]}

Colin, X. ^{[1
]}

Audouin, L. ^{[1
]}

Verdu, J. ^{[1
]}

机构：

[1] LIM UMR 8006 ENSAM, F-75013 Paris, France

来源：

POLYMER DEGRADATION AND STABILITY | 2007年 / 92卷 / 02期

关键词：

oxidation; chain scission; morphology; embrittlement;

D O I：

10.1016/j.polymdegradstab.2006.11.012

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 thermal oxidation of polyethylene films in air at 80 degrees C and 90 degrees C has been studied by tensile testing, IR spectrophotometry and molar mass determination from rheometric measurements. In the conditions under study, the polymer predominantly undergoes chain scission and embrittles suddenly when the weight average molar mass reaches a critical value (90 kg mol(-1)), far before significant damage of the entanglement network (M-e = 1.9 kg mol(-1)) in the amorphous phase. The following embrittlement mechanism is proposed: chain scission in the amorphous phase induces chemicrystallization. The thickness of the interlamellar amorphous layer (I-a) decreases until a critical value of the order of 6-7 nm, below which plasticity cannot be activated and the polymer behaves in a brittle manner, as previously shown for virgin polyethylene. Using (I-a, M-W) maps, it is possible to explain the differences observed in the embrittlement behaviour of semi-crystalline polymers predominantly undergoing chain scission. (c) 2006 Elsevier Ltd. All rights reserved.

引用

页码：231 / 238

页数：8

共 53 条

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