Sains Malaysiana 43(2)(2014): 219–225

Possibility of Improving the Properties of Mahang Wood (Macaranga sp.)

through Phenolic Compreg Technique

(Kemungkinan untuk Meningkatkan Sifat Kayu Mahang (Macaranga sp.)

melalui Teknik Compreg Fenolik)

A.F. ANG¹, A. ZAIDON*¹, E.S. BAKAR¹, S. MOHD HAMAMI¹, U.M.K. ANWAR²

& M. JAWAID³

¹Faculty of Forestry, Universiti Putra Malaysia, 43400 Serdang, Selangor D.E. Malaysia

²Forest Research Institute Malaysia, 52109 Kepong, Selangor D.E. Malaysia

³Institute of Tropical Forestry and Forest Products, Universiti Putra Malaysia

43400 Serdang, Selangor D.E. Malaysia

Received: 2 January 2013/Accepted: 17 May 2013

ABSTRACT

Lesser known wood species (LKS) have the potentials to become an alternative sources of timber supply for wood based industries if their properties can be improved. In this study, Mahang wood (Macaranga sp.) was impregnated 15% (w/v) low molecular weight phenol formaldehyde (LMWPF) followed by compressing in a hot press at 70, 60 and 50% compression ratios (CR). The treated wood was partially dried in an oven at 65°C until 10% moisture content and subsequently followed by curing at 150°C for 30 min in a hot press. The results showed that the phenolic compreg technique had successfully increased the dimensional stability and mechanical properties of the wood. The polymer retention calculated based on weight gain regardless of compression ratio was approximately 30%. The majority of the properties were improved by the degree of compression in a hot press. Nevertheless, thickness swelling and swelling coefficient increased which were due to spring back effect. As regards to specific strength (strength to density ratio), the compreg wood displayed lower strength and stiffness in lateral direction compared with untreated solid wood. However, the specific compressive strength perpendicular to grain and hardness of the compreg wood were superior than untreated solid wood. The treatment had also changed the wood into highly resistant to fungal decay.

Keywords: Compression ratio; Mahang wood; phenol formaldehyde; Pycnoporus sanguineus; swelling coefficient

ABSTRAK

Spesies kayu kurang dikenali (LKS) mempunyai potensi untuk dijadikan sebagai bekalan kayu alternatif kepada industri kayu jika sifat mereka yang kurang baik dapat dipertingkatkan. Dalam kajian ini, compreg Mahang diperbuat dengan pengisitepuan resin fenol formaldehid berat molekul rendah (LMWPF) (15% w/v) diikuti dengan mampatan di bawah haba pada kadar mampatan 70, 60 dan 50%. Kayu yang telah diisitepuan dengan resin dikering sebahagian pada suhu 65°C sehingga mencapai kelembapan 10% kemudian diikuti dengan kering sepenuhnya pada suhu 150°C selama 30 min di bawah penekan haba. Keputusan menunjukkan bahawa teknik compreg fenolik telah berjaya meningkatkan kestabilan dimensi dan sifat mekanikal kayu. Retensi polimer dikira berdasarkan peratus berat dapatan tanpa mengambil kira kadar mampatan adalah lebih kurang 30%. Majoriti sifat kayu telah ditingkatkan oleh darjah mampatan di dalam penekan haba. Walau bagaimanapun, peningkatan dalam pembengkakan tebal dan pekali pembengkakan adalah disebabkan oleh kesan pemantulan semula. Berkenaan kekuatan khusus (nisbah kekuatan kepada ketumpatan), kayu compreg menunjukkan kekuatan dan kekakuan yang lebih rendah dalam arah sisi berbanding kayu yang tidak dirawat. Walau bagaimanapun, kekuatan khusus bagi mampatan serenjang urat kayu dan kekerasan kayu compreg adalah lebih baik daripada kayu yang tidak dirawat. Rawatan ini juga telah mengubah kayu menjadi sangat tahan kepada kerosakan kulat.

Kata kunci: Fenol formaldehid; kadar mampatan; kayu Mahang; pekali pembengkakan; Pycnoporus sanguineus

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*Corresponding author; email: zaidon@putra.upm.edu.my