• SOO-JIN PARK

Articles written in Bulletin of Materials Science

• Thermal and curl properties of PET/PP blend fibres compatibilized with EAG ternary copolymer

Blends of polyethylene terephthalate (PET)/polypropylene (PP) and the ternary copolymer ethylene–acrylic ester–glycidyl methacrylate (EAG) as the compatibilizer were prepared using a twin-screw extruder. The thermal properties,densities and morphologies of the blends were determined using various techniques. Next, PET/PP blend fibres were prepared using a melt–spinning system, and their curl properties were investigated. Scanning electron microscopy (SEM) results showed that the number of PP particles in the PET matrix and size of the PP phase decreased as the EAG content increased. The melting temperature ($T_{\rm m}$) and cooling crystallization ($T_{\rm cc}$) values of PP in the PET/PP blends decreased significantly after the addition of 1% EAG. The density of the PET/PP blend fibres decreased significantly with increase in the EAG and PP contents. After curl formation, the curl length of PP in the fibres was shorter than that of PET.

• Preparation of Cu nanoparticles by a pulsed wire evaporation process for conductive ink applications

In the present study, Cu colloidal nanoparticles and nanopowders were successfully synthesized by a pulsed wire evaporation process. Cu-based nano-inks were prepared by mixing Cu nanoparticles with acrylic resin and solvent.Cu nanoparticles with a particle size of <20 nm were uniformly dispersed in ethylene glycol. The Cu nanopowders were successfully coated with an organic solvent composed of a hydrocarbon compound. This organic coating effectively inhibited the oxidation of Cu nanopowders. In addition, the stability of dispersion of Cu nanoparticles in the inks was improved by a ball-milling process. The electrical conductivity of the prepared Cu nano-inks was 10–28 $\mu$S cm$^{−1}$ for 20–40 wt% of Cu.

• Preparation and characterization of graphite/thermosetting composites

Graphite/thermosetting composites were prepared via a melt blending and compression–curing process using epoxy and phenolic resins as polymer matrices. The flexural strength, flexural modulus and electrical conductivity of thecomposites were investigated. The composites containing 55wt% graphite showed the maximum flexural strength and modulus. Scanning electron microscopy results showed that the thermosetting resins and graphite were uniformly dispersed on the fractured surface of the composites. The electrical conductivity of the composites increased with an increase in the graphite content. The flexural and electrical properties of the composites improved significantly by the addition of a carbon fibre cloth (CFC) or a CFC and carbon nanotubes.

• Synthesis and application of a polymeric intumescent ﬂame retardant for cotton fabric

A novel polymeric intumescent ﬂame retardant containing phosphorus, nitrogen and sulphur (poly(ditrimethylolphosphono thiourea (PDTPT)) was synthesized, and its chemical structure was characterized by Fourier-transform infrared spectroscopy, ¹Hand ³¹P nuclear magnetic resonance spectroscopy and elemental analysis. The molecular weight and thermal properties of PDTPT were measured by using gel permeation chromatography and thermogravimetric analysis. PDTPT exhibited good thermal stability, char formation and swelling performance. The initial thermal decomposi-tion temperature and quality residual rate at 600°C of PDTPT were 282°C and 48.8%, respectively. When the mass fraction of PDTPT was 25 wt%, the limiting oxygen index-value of the cotton fabric/PDTPT composite was 27, an increase from 18 for the pure cotton fabric. Subsequent thermal analysis and scanning electron microscopy showed that PDTPT addition reduced the initial degradation temperature and the weight loss rate of the cotton fabric by forming a thick and tight carbon layer on its surface.

• # Bulletin of Materials Science

Current Issue
Volume 42 | Issue 6
December 2019

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019