Sains Malaysiana 42(4)(2013): 435–441

Effect of Maleated Compatibiliser (PBS-g-MA) Addition on the Flexural Properties and Water Absorption of Poly(butylene succinate)/kenaf Bast Fibre Composites

(Kesan Penambahan ‘Maleated Compatibiliser’ (PBSgMA) ke Atas Sifat Fleksur dan Penyerapan Air Komposit Poli(butilena suksinat)/gentian Kulit Kenaf)

M.Z. Ahmad Thirmizir, Z.A. Mohd Ishak* & R. Mat Taib

School of Materials and Minerals Resources Engineering, Seri Ampangan Engineering Campus

Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang, Malaysia

M.Z. Ahmad Thirmizir, Z.A. Mohd Ishak* & R. Mat Taib

Cluster for Polymer Composites (CPC), Engineering and Technology Research Platform

Universiti Sains Malaysia, Kampus Kejuruteraan,14300 Nibong Tebal, Pulau Pinang, Malaysia

S. Rahim

Wood Chemistry and Protection Programme, Forest Research Institute Malaysia (FRIM)

52109 Kepong, Selangor D.E.Malaysia

Received: 5 June 2011 / Accepted: 18 May 2012

ABSTRACT

Poly(butylene succinate) (PBS) composites with 30 wt.% loading of kenaf bast fibre (KBF) were compatibilised with 5 wt.% maleated PBS (PBS-g-MA). The maleic anhydride (MA) concentration in the compatibiliser was either 3, 5, 7 or 10 phr. In general, the compatibilised composites showed better flexural properties than the un-compatibilised composite. The highest increment in the flexural strength and modulus of 12.7 and 8.9%, respectively, were obtained with the addition of PBS-g-MA with MA concentration of 5 phr. Compatibilised and un-compatibilised PBS/KBF composites were immersed in distilled water for 90 days. The absorption of water by all the composites was observed to follow Fick’s law. The equilibrium moisture content, M_m, of the composites with PBS-g-MA at 3, 5 and 7 phr of MA concentrations was lower than that of the un-compatibilised composite due to improved fiber-matrix interfacial adhesion and reduction of voids content. Both un-compatibilised and compatibilised composites showed dimensional instability after the water absorption. This was probably due to the degradation of the fibre-matrix interfacial adhesion and fibre integrity. The flexural properties of these composites decreased after the water absorption. After re-drying only some of the flexural properties were recovered from plasticizing effect of water.

Keyword: Composites; dimensional stability; interfacial adhesion; mechanical properties; water absorption

ABSTRAK

Komposit poli(butilena suksinat) (PBS) dengan pembebanan 30 % berat gentian kulit kenaf telah ditambah dengan 5 % berat ‘maleated PBS’ (PBSgMA). Kepekatan maleik anhidrida (MA) dalam penserasi yang digunakan ialah 3, 5, 7 atau 10 phr. Secara umumnya, komposit yang ditambah dengan penserasi menunjukkan sifat fleksur yang lebih baik berbanding komposit tanpa penserasi. Peningkatan kekuatan dan modulus fleksural yang tertinggi iaitu sebanyak 12.7 dan 8.9 % telah diperoleh oleh komposit dengan penambahan PBSgMA dengan kepekatan MA 5 phr. Komposit PBS/KBF dengan dan tanpa penserasi telah direndam dalam air suling untuk tempoh 90 hari. Penyerapan air oleh semua komposit adalah mengikut Hukum Fick. Kandungan lembapan pada keseimbangan, M_m, bagi komposit dengan penambahan PBSgMA pada kepekatan MA 3, 5 dan 7 phr adalah lebih rendah berbanding komposit tanpa penserasi kerana kesan penambahbaikan pelekatan antara muka gentian-matriks dan pengurangan kandungan lompang-lompang dalam komposit. Kedua-dua komposit tanpa dan dengan penserasi menunjukkan ketidakstabilan dimensi selepas penyerapan air berlaku. Ini adalah kerana degredasi pelekatan berlaku antara muka gentian-matriks dan integriti gentian. Sifat fleksural komposit-komposit itu juga menurun selepas penyerapan air. Selepas proses pengeringan sampel, hanya sebahagian sifat fleksural diperoleh semula.

Kata kunci: Kestabilan dimensi; komposit; pelekatan antara muka; penyerapan air; sifat mekanik

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*Corresponding author; email: zharif@eng.usm.my