High-energy radiation forming chain scission and branching in polypropylene

被引：69
作者：
Otaguro, H. [2 ]
de Lima, L. F. C. P. [2 ]
Parra, D. F. [2 ]
Lugao, A. B. [2 ]
Chinelatto, M. A. [3 ]
Canevarolo, S. V. [1 ]
机构：
[1] Univ Fed Sao Carlos, Dept Mat Engn, BR-13560 Sao Carlos, SP, Brazil
[2] Inst Nucl Energy Res, BR-05508000 Sao Paulo, Brazil
[3] UFSCar Dema, Mat Characterizat & Dev Ctr, Sao Carlos, SP, Brazil
来源：
RADIATION PHYSICS AND CHEMISTRY | 2010年 / 79卷 / 03期
基金：
巴西圣保罗研究基金会;
关键词：
Chain scission; Branching; Gamma radiation; Polypropylene; CSDF; HIGH-DENSITY POLYETHYLENE; DEGRADATION; EVOLUTION;
D O I：
10.1016/j.radphyschem.2009.11.003
中图分类号：
O64 [物理化学（理论化学）、化学物理学];
学科分类号：
070304 ; 081704 ;
摘要：
The degradation of high molecular weight isotactic polypropylene (iPP) subjected to gamma rays irradiation up to 100 kGy in inert atmosphere was analyzed. The investigation relied upon complex viscosity, elastic modulus, gel fraction, morphology of the insoluble fraction and deconvoluted molecular weight distribution (MWD) curves. At low irradiation doses, already at 5 kGy, the MWD curve is strongly shifted to the low molecular weight side showing chain scission, which is confirmed using the calculated chain scission distribution function (CSDF). At high dose levels, the appearance of a shoulder in the high molecular weight side of the MWD curve indicates the formation of chain branching. The presence of a considerable insoluble fraction at these high dose levels indicates also the formation of cross-linking, which has different morphology then the insoluble fraction present in the original iPP. The theological results show changes in the molecular structure of irradiated samples in agreement with the gel content data. The chromatographic and theological data has shown that gamma irradiation of iPP produces chain scission, branching and cross-linking. (C) 2009 Published by Elsevier Ltd.
引用
收藏
页码：318 / 324
页数：7
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