Sains Malaysiana 40(7)(2011): 795–802

Optimization of Microencapsulation Process for Self-Healing

Polymeric Material

(Pengoptimuman Proses Mikro-pengkapsulan untuk Bahan Polimer Penyembuhan-Sendiri)

Sonja Then* & Gan Seng Neon

Department of Chemistry,Faculty of Science, University of Malaya

50603 Kuala Lumpur, Malaysia

Noor Hayaty Abu Kasim

Department of Conservative Dentistry, Faculty of Dentistry

University of Malaya, 50603 Kuala Lumpur, Malaysia

Received: 23 October 2009 / Accepted: 28 July 2010

ABSTRACT

A series of poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) was successfully prepared by in situ polymerization. The effect of diverse process parameters and ingredients on the morphology of the microcapsules was observed by SEM, optical microscopy (OM) and digital microscopy. Different techniques for the characterization of the chemical structure and the core content were considered such as FT-IR and 1H-NMR as well as the characterization of thermal properties by DSC. High yields of free flowing powder of spherical microcapsules were produced. The synthesized microcapsules can be incorporated into another polymeric host material. In the event the host material cracks due to excessive stress or strong impact, the microcapsules would rupture to release the DCPD, which could polymerize to repair the crack.

Keywords: Microcapsules; micro-cracking; in situ polymerization; self-healing material

ABSTRAK

Siri mikrokapsul poliurea-formaldehid (PUF) yang mengandungi disiklopentadiena (DCPD) berjaya disediakan melalui proses pempolimeran in situ. Kesan kepelbagaian parameter proses dan bahan reaktan terhadap morfologi mikrokapsul telah diperhatikan melalui SEM, mikroskop optik (OM) dan mikroskop digital. Pelbagai kaedah seperti FT-IR dan 1H-NMR diguna untuk mencirikan struktur kimia serta kandungan teras mikrokapsul. Selain itu, sifat terma mikrokapsul juga dianalisis menggunakan DSC. Sfera mikrokapsul yang terhasil adalah dalam bentuk serbuk putih dengan peratus hasilan yang tinggi. Mikrokapsul ini boleh digabungkan ke dalam bahan polimer hos yang lain. Apabila bahan induk retak akibat tekanan yang berlebihan atau impak yang kuat, mikrokapsul akan pecah dan membebaskan DCPD untuk membaiki keretakan melalui proses pempolimeran.

Kata kunci: Bahan penyembuhan-sendiri; keretakan-mikro; mikrokapsul; pempolimeran in situ

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*Corresponding author; email: sonja@siswa.um.edu.my