This paper describes the physical properties of filled Nylon6 composites resin with nano-sized carbon black particle and graphite nanofibers prepared by melt extrusion method. In improving adhesions between resin and fillers, the surface of the carbon filler materials were chemically modified by thermo-oxidative treatments and followed by treatments of silane coupling agent. Crystallization temperature and rate of crystallization increased with increases in filler concentration which would act as nuclei for crystallization. The silane treatments on the filler materials showed effect of reduction in crystallization temperature, possibly from enhancement in wetting property of the surface of the filler materials. Percolation transition phenomenon at which the volume resistivity was sharply decreased was observed above 9 wt% of carbon black and above 6 wt% of graphite nanofiber. The graphite nanofibers contributed to more effectively in an increase in electrical conductivity than carbon black did, on the other hand, the silane coupling agent negatively affected to the electrical conductivity due to the insulating property of the silane. Positive temperature coefficient (PTC) phenomenon, was observed as usual in other composites, that is, temperature increase results conductivity increase. The dispersity of the fillers were excellently approached by melt extrusion of co-rotational twin screw type and it could be illustrated by X-ray diffraction and SEM.

The effects of fiber surface-treatment and sizing on the dynamic mechanical properties of unidirectional and 2-directional carbon fiber/nylon 6 composites by means of dynamic mechanical analysis have been investigated in the present study. The interlaminar shear strengths of 2-directional carbon/nylon 6 composites sized with various thermosetting and thermoplastic resins are also measured using a short-beam shear test method. The result suggests that different surface-treatment levels onto carbon fibers may influence the storage modulus and tan δ behavior of carbon/nylon 6 composites, reflecting somewhat change of the stiffness and the interfacial adhesion of the composites. Dynamic mechanical analysis and short-beam shear test results indicate that appropriate use of a sizing material upon carbon fiber composite processing may contribute to enhancing the interfacial and/or interlaminar properties of woven carbon fabric/nylon 6 composites, depending on their resin characteristics and processing temperature.

국내에서 생산하고 있는 Nylon 6 망사의 원사는 대부분 일본에서 수입하여 제망해서 수출하고 있다. 그러나 우리가 수입하고 있는 원사중 어느 회사의 원사가 우수한지 또한 염색 가공후의 망사의 성질변화에 대하여서는 그다지 알려져 있지 않으며 그뿐만 아니라 같은 Nylon 6 망사라 할지라도 제조 공정에 따라 망사의 성질이 달라질 수 있으므로 저자들은 일산 Nylon6 망사를 가지고 염색전과 후의 강신도와 염색후의 수축등을 시험 비교해 보았다. 특히 망사는 수중에서 사용되기 때문에 습윤시의 인장 강도와 신장이 겁습에 비해 어떻게 변화하는가를 관찰하였다.

Thermogravimetric analysis (TGA) is a thermal analysis technique that the mass of sample is measured by time and temperature changes. In this study, TGA was applied for estimating the proportion of Nylon-6,6 nanofibers in the cement paste as well as the decomposition temperature of Nylon-6,6 nanofibers. An electrospinning process was conducted for producing nanofibers and adding directly into the cement powder. The TGA results show that there was approximately 0.5 % of nanofibers in the composite pastes. Besides, the decomposition temperature of Nylon-6,6 nanofibers was clarified in the range of 300℃ to 410℃.