Transition of complex permittivity losses in Hevea rubber latex from conductivity losses to dipolar losses at 2.6 GHz

J. Hassan, . and Kaida Khalid, . and W. M. D. Wan Yusoff, . Transition of complex permittivity losses in Hevea rubber latex from conductivity losses to dipolar losses at 2.6 GHz. pp. 65-72. ISSN 1511-1768

Dielectric properties of Hevea rubber latex with moisture content 38-98 were measured using the open-ended coaxial line sensor coupled to the Automated Network Analyser. Measurements were made at frequencies 0.2 GHz-20 GHz and at selected temperatures -30deg.C to 50deg.C. Complex permittivity losses or dielectric loss factor showed a very interesting phenomena at 0.2 GHz to 2.6 GHz where a transition occured from conductivity losses to dipolar losses. Below 2.6 GHz the losses were due to the conducting phases in the Hevea latex arising from proteins fatty acid soaps phospholipids and various types of ohmic species. Higher losses were achieved from latex concentrate due to the addition of ammonia as preservative. Above 2.6 GHz the losses were governed by orientation of the water molecules. The transition was clearly observed in the plots of dielectric losses versus temperature at 0.2 0.6 1.0 1.4 1.8 2.2 and 2.6 GHz for latex concentrate fresh latex diluted fresh latex and deionised water at moisture contents 38 0.56 89 and 100 respectively.

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Abstract

Dielectric properties of Hevea rubber latex with moisture content 38-98 were measured using the open-ended coaxial line sensor coupled to the Automated Network Analyser. Measurements were made at frequencies 0.2 GHz-20 GHz and at selected temperatures -30deg.C to 50deg.C. Complex permittivity losses or dielectric loss factor showed a very interesting phenomena at 0.2 GHz to 2.6 GHz where a transition occured from conductivity losses to dipolar losses. Below 2.6 GHz the losses were due to the conducting phases in the Hevea latex arising from proteins fatty acid soaps phospholipids and various types of ohmic species. Higher losses were achieved from latex concentrate due to the addition of ammonia as preservative. Above 2.6 GHz the losses were governed by orientation of the water molecules. The transition was clearly observed in the plots of dielectric losses versus temperature at 0.2 0.6 1.0 1.4 1.8 2.2 and 2.6 GHz for latex concentrate fresh latex diluted fresh latex and deionised water at moisture contents 38 0.56 89 and 100 respectively.

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Item Type:	Article
AGROVOC Term:	Hevea brasiliensis
AGROVOC Term:	Hevea rubber
AGROVOC Term:	Latex plants
AGROVOC Term:	Dielectric properties
AGROVOC Term:	Transition elements
AGROVOC Term:	Temperature
AGROVOC Term:	Moisture content
AGROVOC Term:	Energy losses
AGROVOC Term:	Measurement
Geographical Term:	Malaysia
Depositing User:	Ms. Suzila Mohamad Kasim
Last Modified:	28 Apr 2025 03:23
URI:	http://webagris.upm.edu.my/id/eprint/23150

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