Sains Malaysiana 43(2)(2014): 241–245

Dynamic Mechanical and Dielectric Properties of Modified Surface Chitosan/

Natural Rubber Latex

(Sifat Mekanik Dinamik dan Dielektrik Permukaan Chitosan yang Diubahsuai / Lateks Getah Asli)

WIRACH TAWEEPREDA*

Department of Materials Science and Technology, Faculty of Science, Prince of Songkla University

Hat-Yai, Songkhla 90110, Thailand

Received: 5 February 2013/Accepted: 30 July 2013

ABSTRACT

Biodegradable polymeric films, obtained from chitosan/natural rubber latex (CS/NRL) blends with different compositions, have been prepared by wetting process. The blends were characterized by dynamic mechanical thermal analysis (DMTA) and found that the CS/NRL blends are thermodynamically incompatible. This is evident from the presence of two glass transitions, corresponding to CS and NRL phases in the blend. The mechanical properties of the CS/NRL blends were improved with increasing the amount of chitosan and after surface treatment with sulphuric acid due to the sulfonate ionic interaction. The dielectric properties was determined using Precision LCR meter in the frequency range 75 kHz up to 30 MHz. After CS/NRL surface treatment with sulphuric acid at high content of chitosan showed the highest dielectric constant. The surface properties of the CS/NRL blend films before and after surface treatment were confirmed by atomic force microscopy (AFM), respectively.

Keywords: Biopolymer; chitosan; dielectric properties; natural rubber; surface modification

ABSTRAK

Penggunaan filem terbiourai yang diperoleh daripada campuran (CS/NRL) lateks getah asli/ kitosan dengan komposisi yang berbeza, telah disediakan secara proses basah. Campuran dicirikan menggunakan teknik analisis haba mekanik dinamik (DMTA) dan mendapati bahawa campuran CS/NRL semula jadi tidak serasi. Ini adalah jelas daripada kewujudan dua peralihan kaca, yang sesuai dengan fasa CS dan NRL dalam adunan. Sifat mekanik campuran CS/NRL telah dipertingkatkan dengan meningkatkan jumlah kitosan dan selepas rawatan permukaan menggunakan asid sulfurik berlaku interaksi ionik sulfonat. Sifat dielektrik ditentukan menggunakan LCR ketepatan meter dalam kekerapan julat 75 kHz sehingga 30 MHz. Selepas rawatan permukaan CS/NRL dengan asid sulfurik pada kandungan yang tinggi daripada kitosan menunjukkan berlakunya pembentukan malar dielektrik yang tertinggi. Sifat permukaan CS/NRL menggabungkan filem sebelum dan selepas rawatan permukaan telah disahkan masing-masing oleh Microskop berkuat-kuasa atom (AFM).

Kata kunci: Getah asli; kitosan; permukaan pengubahsuaian; polimer-Bio ditawarkan; sifat dielektrik

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*Corresponding author; email: wirach.t@psu.ac.th