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                                       Details for article 3 of 7 found articles
 
 
  Influence of Anisotropy on the PTC Effect in Injection Moulded Samples of CB-filled Polyethylene and Polystyrene
 
 
Title: Influence of Anisotropy on the PTC Effect in Injection Moulded Samples of CB-filled Polyethylene and Polystyrene
Author: Klason, Carl
Kubat, Josef
Appeared in: International journal of polymeric materials
Paging: Volume 11 (1985) nr. 1 pages 47-65
Year: 1985-03-01
Contents: This paper reports on measurements of the temperature dependence of resistivity, ρ, in injection moulded samples of LDPE, HDPE, and PS filled with two grades of carbon black (CB). The CB concentration was adjusted to give a relatively small PTC-effect in isotropic (annealed) samples. It was found that the orientation of the matrix polymer that occurred during the injection moulding process highly enhanced the PTC-efficiency of all the compounds used. The magnitude of this effect and the level of RT resistivity were orientation dependent. Upon annealing (second heating run) the behaviour of the isotropic samples was recovered. In general, ρ increased with the degree of orientation in a fashion similar to the effects associated with lowering the CB content. One of the effects observed in highly oriented samples was a pronounced frequency-dependence of the resistivity (ρ decreasing at higher frequencies), and a non-ohmic I-V-behaviour. The ρ-data relate to d.c. and 1 kHz. Samples with higher and lower orientation were obtained by microtoming the surface and core portions of the injection moulded test bars.
Publisher: Taylor & Francis
Source file: Elektronische Wetenschappelijke Tijdschriften
 
 

                             Details for article 3 of 7 found articles
 
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