Malaysian Journal of Analytical Sciences Vol 20 no 5 (2016): 1104 - 1111

DOI: http://dx.doi.org/10.17576/mjas-2016-2005-16

ZETA POTENTIAL AND ENVIRONMENTAL SCANNING ELECTRON MICROSCOPY ANALYSIS IN DEPROTEINISATION OF NATURAL RUBBER LATEX

(Analisis Keupayaan Zeta dan Pengimbas Persekitaran Mikroskopi Elektron di dalam Penyahprotein Lateks Getah Asli)

Nurulhuda Abdullah*, Asrul Mustafa, Mok Kok Lang

Technology and Engineering Division,

Malaysian Rubber Board, 47000 Sungai Buloh, Selangor Darul Ehsan, Malaysia

*Corresponding author: nurulhuda.a@lgm.gov.my

Received: 10 June 2015; Accepted: 21 July 2016

Abstract

This paper describes the effect of protein denaturants namely, urea and sodium dodecyl sulphate (SDS) in the deproteinisation of high ammonia natural rubber latex (HA-NRL). It had been shown that latex proteins were reduced more in the presence of urea alone (48%) than in the presence of SDS (18%). The synergistic effect when both urea and SDS were used in the latex deproteinisation attributed to the higher protein removal efficacy (55%). Higher zeta potential value was observed when only SDS was used, suggesting higher colloidal stability. Environmental Scanning Electron Microscopy (ESEM) revealed that without SDS, the use of urea single-handedly in the deproteinisation process promoted aggregation of latex particles, possibly due to the dismissal of latex proteins which helped to stabilise latex colloidal. Thus, it is most likely that urea serves as a protein unfolding agent during latex deproteinisation process, while SDS functions as a latex stabiliser with no significant effects on latex proteins discharge.

Keywords: urea, sodium dodecyl sulphate, deproteinisation, zeta potential, environmental scanning electron microscopy

Abstrak

Kertas kerja ini menghuraikan kesan bahan-bahan pengubah sifat protein iaitu urea dan natrium dodekil sulfat (NDS) dalam penyahprotein lateks getah asli tinggi ammonia (HA-NRL). Ia telah menunjukkan bahawa protein lateks lebih banyak dikurangkan dengan kehadiran urea sahaja (48%) berbanding dengan kehadiran NDS sahaja (18%). Keberkesanan penyingkiran protein yang lebih tinggi (55%) mungkin telah disebabkan oleh kesan sinergi apabila kedua-dua urea dan NDS digunakan di dalam penyahprotein lateks. Nilai keupayaan zeta yang tinggi diperhatikan apabila hanya NDS digunakan, menunjukkan kestabilan koloid yang lebih tinggi. Pengimbas Persekitaran Mikroskopi Elektron (ESEM) menunjukkan bahawa tanpa NDS, penggunaan hanya urea dalam proses penyahprotein menyumbang kepada kesan pengagregatan zarah lateks, kemungkinan disebabkan oleh penyingkiran protein lateks yang membantu dalam kestabilan koloid lateks. Oleh yang demikian, besar kemungkinan fungsi utama urea semasa proses penyahprotein lateks adalah sebagai ejen pembuka protein manakala NDS berfungsi sebagai penstabil lateks tanpa kesan ketara pada penyingkiran protein lateks.

Kata kunci: urea, natrium dodekil sulfat, penyahprotein, keupayaan zeta, pengimbas persekitaran mikroskopi elektron

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