Microencapsulation and characterization of polyamic acid microcapsules containing n-octadecane via electrospraying method
As an intermediate polymer of polyimide, polyamic acid (PAA) was synthesized by ternary copolymerization of pyromellitic dianhydride (PMDA), 4,4′-oxydianiline (4,4′-ODA) and 2,6-diaminoanthraquinone (2,6-DAAQ). Furthermore, spherical core/shell PAA/n-octadecane microcapsules were produced via coaxial electrospraying. The molecular structure of PAA was determined by fourier transformed infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1H NMR). The morphology, microstructure and thermal properties of PAA microencapsulated n-octadecane were investigated by field-emission scanning electron microscopy (FE-SEM), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The diameters of microcapsules ranged from 0.5 to 3 μm, and the surface morphology was influenced by the core (n-octadecane) solution feed rate. With core feed rate increasing, the surface of microcapsules turned from smooth and uniform to sags and crests, moreover, their mean diameter increased and then decreased. Meanwhile, the DSC results revealed that microcapsules had relatively high enthalpy (∼107 J/g) and associated by supercooling phenomenon. Due to the excellent thermal stability of shell materials, the 40% weight loss temperature of PAA microcapsules reached as high as 500 °C.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: December 1, 2015
More about this publication?
- Materials Express is a peer-reviewed multidisciplinary journal reporting emerging researches on materials science, engineering, technology and biology. Cutting-edge researches on the synthesis, characterization, properties, and applications of a very wide range of materials are covered for broad readership; from physical sciences to life sciences. In particular, the journal aims to report advanced materials with interesting electronic, magnetic, optical, mechanical and catalytic properties for industrial applications.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Ingenta Connect is not responsible for the content or availability of external websites