Sains Malaysiana 46(5)(2017): 795–801

http://dx.doi.org/10.17576/jsm-2017-4605-14

Membran Selulosa Kenaf Terjana Semula daripada Larutan Akues NaOH/Urea yang Digumpal Menggunakan Asid Sulfurik

(Regenerated Kenaf Cellulose Membrane from NaOH/Urea Aqueous Solution by Coagulating with Sulphuric Acid)

NOR AZIAWATI AZAHARI¹, SARANI ZAKARIA¹*, HATIKA KACO¹, GAN SIN YEE¹, CHIN HUA CHIA¹, SHARIFAH NABIHAH SYED JAAFAR¹ & MOHD SHAIFUL SAJAB²

¹Makmal Biosumber dan Biopenurasan, Pusat Pengajia Fizik Gunaan, Fakulti Sains dan Teknologi

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

²Pusat Penyelidikan Teknologi Proses Mampan (CESPRO), Fakulti Kejuruteraan dan Alam Bina

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

Diserahkan: 18 Ogos 2016/Diterima: 4 Oktober 2016

ABSTRAK

Membran selulosa terjana semula (MS) daripada pulpa teras kenaf telah berjaya dihasilkan menggunakan kaedah pra penyejukan dan digumpal menggunakan larutan asid sulfurik. MS disediakan daripada pelarutan selulosa kenaf dalam larutan akues NaOH/urea dan larutan selulosa seterusnya digumpal dengan H₂SO₄ pada kepekatan 5-12 peratus berat (% bt.) selama 1-10 min. Pengaruh kepekatan penggumpal H₂SO₄ dan masa penggumpalan ke atas struktur, saiz liang, sifat mekanik dan ketelusan cahaya MS telah dikaji menggunakan pembelauan sinar-X (XRD), imbasan mikroskop elektron tekanan boleh ubah (VPSEM), penguji regangan dan spektrofotometer ultra-violet sinar tampak (UV-vis). Keputusan VPSEM menunjukkan perubahan saiz liang membran bergantung kepada kepekatan larutan penggumpal H₂SO₄, manakala masa penggumpalan tidak mempengaruhi saiz liang membran. Membran yang direndam dengan larutan penggumpal pada kepekatan 10 % bt. dan masa pembekuan yang sederhana iaitu 5 min menunjukkan sifat mekanik yang lebih baik dengan nilai kekuatan regangan masing-masing 41.9 dan 43.5 MPa. Oleh itu, kajian ini dapat memberikan maklumat mengenai penyediaan MS dengan pelbagai saiz liang dan sifat mekanik dengan pengubahsuaian kepekatan dan masa penggumpalan.

Kata kunci: Larutan akues NaOH/urea; membran selulosa terjana semula; penggumpal; pulpa teras kenaf; sifat fizikal

ABSTRACT

Regenerated cellulose membranes (RC) from kenaf core pulp have been produced using the pre cool method and coagulated using sulfuric acid (H₂SO₄) solution. RC prepared from kenaf cellulose was dissolved in NaOH/urea solvent and subsequently coagulated with H₂SO₄ solution at concentration 5-12 wt. % for 1 - 10 min. The effects of concentration of acid and coagulating time on the structure, pore size, mechanical properties and transparency of RC were studied using X-ray diffraction (XRD), variable pressure scanning electron microscopy (VPSEM), tensile tester and spectrometer ultra violet (UV- Vis) transmission, respectively. The results from VPSEM showed the pore size of the membranes changed as a function of the concentration of H₂SO₄ coagulant, whereas it was hardly changed with coagulation time. RC membranes coagulated in 10 wt. % concentration of H₂SO₄ solution and 5 min coagulation time exhibited better mechanical properties with tensile strength value 41.9 and 43.5 MPa, respectively. Thus, this work provided an optimal coagulation condition for preparing RC membranes in the solvent system and scientific information for controlling the properties and pore sizes of the membranes.

Keywords: Coagulant; kenaf core pulp; NaOH/urea aqueous solution; physical properties; regenerated cellulose membrane

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*Pengarang untuk surat-menyurat; email: szakaria@ukm.edu.my