Sains Malaysiana 42(4)(2013): 469–473

Effects of Silica on the Formation of Epoxidised Natural Rubber/Polyvinyl Chloride Membrane

(Kesan Pengisi Silika ke atas Pembentukan Membran Getah Asli Terepoksida/Polivinil klorida)

Nazwa Jon, Ibrahim Abdullah* & Rizafizah Othaman

School of Chemical Sciences and Food Technology, Faculty of Science and Technology

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor D.E. Malaysia

Received: 11 June 2011 / Accepted: 1 May 2012

ABSTRACT

The presence of pores plays an important role for many membrane processes especially in ultrafiltration and microfiltration. Epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) membranes filled with two types of silica fillers were prepared via simultaneous solvent exchange and evaporation of solvent technique. Two types of silica, i.e. microsilica (microcrystalline silica powder) and nanosilica (generated from tetraethoxysilane (TEOS)) were used. The chemical composition, morphology and mechanical stability of the membranes were studied. Both types of silica showed good interaction with the membrane matrix. The formation of pores depended on the size of silica particles added. Microsilica produced large pores while in-situ generated nanosilica produced nanosized pores. The mechanical properties of membrane improved with the addition of silica. The tensile strength increased from 10.6 MPa to 17.8 MPa and 14.5 MPa for nanosilica and microsilica filled membrane while the tensile modulus increased from 1.6 MPa to 3.8 MPa and 3.4 MPa, respectively. Thus, both types of silica acted as a filler as well as pore forming agent for the ENR/PVC membrane.

Keywords: Epoxidised natural rubber; polyvinyl chloride; pore forming agent; silica; tetraethoxysilane

ABSTRAK

Kehadiran liang memainkan peranan penting dalam kebanyakan proses bermembran terutamanya dalam aplikasi penurasan ultra dan penurasan mikro. Membran getah asli terepoksida (ENR)/polivinil klorida (PVC) terisi dua jenis pengisi silika yang dihasilkan melalui penukaran pelarut dan penyejatan secara spontan. Dua jenis silika digunakan iaitu mikrosilika (serbuk kristal mikrosilika) dan nanosilika (dihasilkan daripada Tetraetoksilana (TEOS)). Komposisi kimia, morfologi dan kestabilan mekanik membran telah dikaji. Kedua-dua jenis silika menunjukkan interaksi yang baik dengan matriks membran. Pembentukan liang bergantung kepada saiz silika yang digunakan. Mikrosilika menghasilkan liang yang besar manakala nanosilika yang terjana secara in-situ menghasilkan liang nano. Sifat mekanik membran menunjukkan peningkatan dengan penambahan silika. Kekuatan tensil bertambah daripada 10.6 MPa kepada 17.8 MPa dan 14.5 MPa untuk membran berpengisi nanosilika dan mikrosilika, manakala tensil modulus bertambah daripada 1.6 MPa kepada 3.8 MPa dan 3.4 MPa untuk setiapnya. Oleh itu, kedua-dua jenis silika bertindak sebagai penguat dan juga eAgen penjana liang untuk membran ENR/PVC.

Kata kunci: Agen penjana liang; getah asli terepoksida; polivinil klorida; silika; tetraetoksilana

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*Corresponding author; email: dia@ukm.my