Yi-hu Song, Qiang Zheng. STUDY ON ISOTHERMAL CRYSTALLIZATION OF CARBON BLACK FILLED HIGH DENSITY POLYETHYLENE THROUGH RHEOLOGY-ELECTRICAL CONDUCTION SIMULTANEOUS MEASUREMENT[J]. Acta Polymerica Sinica, 2013,(5):674-678.
Yi-hu Song, Qiang Zheng. STUDY ON ISOTHERMAL CRYSTALLIZATION OF CARBON BLACK FILLED HIGH DENSITY POLYETHYLENE THROUGH RHEOLOGY-ELECTRICAL CONDUCTION SIMULTANEOUS MEASUREMENT[J]. Acta Polymerica Sinica, 2013,(5):674-678. DOI: 10.3724/SP.J.1105.2013.12422.
Isothermal crystallization behavior of carbon black (CB) filled high density polyethylene (HDPE) at a narrow temperature range from 124.3℃ to 125.3℃ was investigated using a rheology-electrical conduction simultaneous measurement method to detect the formation of percolation network and its influence on viscoelastic evolution involving in crystallization of polymer matrix.The results show that strain
frequency and pre-cooling rate have significant influences on both rheological behavior and electrical resistance evolutions as a function of time.The dynamic storage modulus (G') and resistance (R) exhibit abrupt changes upon crystallization of HDPE.R increases during the crystallization induction period
which is assigned to CB particle diffusion in the polymer melts resulting in a partial breakdown of the original percolation network.On the other hand
G' remains constant until induction time of crystallization and the dyanmic rheological method can detect the structural variation only when relative crystallinity reaching 1%~2%.With proceeding of crystallization
G' increases while R decreases markedly and the later is assigned to CB exclusion from the crystalline phase and aggregation in the amorphous phase.Both the rheological and electric donduction behaviors undergo interconnected changes during isothermal crystallization of filled HDPE while the R variation is much more sensitive than that of dynamic rheological behavior to detect the structural evolution because it can reflect the CB diffusion in the melts before crystallization and the CB aggregation in the amorphous phase upon crystallization.
关键词
流变-导电同步测试高密度聚乙烯炭黑复合体系等温结晶
Keywords
Rheology-electrical conduction simultaneous measurementHigh density polyethylene (HDPE)Carbon black (CB)Composite systemIsothermal crystallization