Sains Malaysiana 44(6)(2015): 869–874

Effect of Sodium Bicarbonate as Blowing Agent on Production of Epoxy Shape Memory Foam using Aqueous Processing Method

(Kesan Natrium Bikarbonat sebagai Agen Tiupan kepada Penghasilan Buih Ingatan

Bentuk Epoksi menggunakan Kaedah Akueus)

MUHAMMAD SYAZWAN FAUZI, DU N.U. LAN*, HAKIMAH OSMAN & SUPRI A. GHANI

School of Material Engineering, Universiti Malaysia Perlis (UniMAP)

Kompleks Taman Muhibah, Jejawi 2, 02600 Perlis, Malaysia

Diserahkan: 15 Januari 2014/Diterima: 15 November 2014

ABSTRACT

Epoxy shape memory foam (ESM) was produced by an advanced aqueous method. Mixture of epoxy, sodium bicarbonate, hardener and ammonium chloride was premixed and emulsified in distilled water by using high speed stirring (at 1200 rpm). The content of sodium bicarbonate used was 5, 10, 15 and 20 phr. Besides that, ammonium chloride was used (based on stoichiometrical content) to also function as acidifying agent in initiating the decomposition process of sodium bicarbonate at lower foaming temperature. The foam morphology was observed using SEM. It was found that higher sodium bicarbonate produced more porosity, more cell size, thinner cell wall and more cell interconnection. Epoxy shape memory foam with 10 phr of sodium bicarbonate exhibited good shape memory property and better compression set. Shape memory behaviour was measured by the recovered time of the transformed sample to its original shape.

Keywords: Aqueous method; compression set; compression test; epoxy shape memory foams; sodium bicarbonate

ABSTRAK

Buih ingatan bentuk epoksi (ESM) telah dihasilkan dengan kaedah akueus. Campuran epoksi, natrium bikarbonat, pengeras dan amonium klorida telah dipracampur dan diemulsi di dalam air suling dengan menggunakan kelajuan pengacau yang tinggi (pada 1200 ppm). Kandungan natrium bikarbonat yang digunakan ialah 5, 10, 15 dan 20 bsr. Di samping itu, amonium klorida telah digunakan (berdasarkan kandungan stoikiometrik) juga berfungsi sebagai agen pengasidan dalam memulakan proses penguraian natrium bikarbonat pada suhu lebih rendah. Morfologi buih telah diperhatikan dengan menggunakan SEM. Didapati bahawa natrium bikarbonat yang lebih tinggi menghasilkan lebih keliangan, saiz sel yang lebih, dinding sel yang nipis dan sambungan antara sel yang banyak. Buih ingatan bentuk epoksi dengan 10 bsr natrium bikarbonat menunjukkan ingatan bentuk yang baik dan set mampatan lebih baik. Tingkah laku ingatan bentuk untuk berubah kepada bentuk asal diukur masanya.

Kata kunci: Buih ingatan bentuk epoksi; kaedah akueus; natrium bikarbonat; set mampatan; ujian mampatan

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*Pengarang untuk surat-menyurat; email: uylan@unimap.edu.my