Three kinds of copolyesters, dispersing agents, were synthesized from the polycondensation reaction of dimethylterephthalate(DMT), dimethylisophthalate (DMI), sebacic acid (SA), and 1,4-butanediol (BD). Carbon black masterbatches were prepared by mixing carbon black into the dispersing agents (1 : 1.3 weight ratio) in a Brabender Plasticorder Using single screw extruder, masterbatches were compounded with poly (ethylene terephthalate) 3 wt% concentration and mechanical properties of the compounds were investigated. Gel permeation chromatography data implied that thermal degradation of polymeric dispersing agents was not significant through dispersion. Capillary rhometer test showed that PBTI has the highest viscosity and shear sensitivity among the three dispersing agents. Vlume resistivities of masterbatch and transmission electron micrographs showed that dispersity of carbon black was improved woth increasing melt viscosity of dispersing agent. The ultimate performance and mechanical characteristics of carbon black filled PET compounds depended directly on dispersion quality of the carbon black in masterbatch. Mechanical properties of compounds were improved with increasing dispersity of carbon black and with increasing content of rigid aromatic group in the copolyester dispersing agent.

Dimethylterephthalate (DMT), dimethylisophthalate (DMI) 그리고 sebacic acid (SA)와 12,4-butanediol (BD)의 에스테르화반응 및 중축합반응으로 세 종류의 copolyester 분산제를 합성하였다. Brabender Plasticorder에서 카본블랙과 합성한 저융점의 copolyester 분산제를 1 : 1.3의 무게비로 혼련하여 마스터뱃치를 제조하였다. 또한 일출압출기를 사용하여 poly-(ethyleneterephthalate)(PET)에 제조한 마스터뱃치를 각각 3 wt% 함유하는 흑색 커마운드를 제조하고 이들의 기계적 물성을 조사하였다. 본 실험에서 사용한 분산제는 마스터

Keywords: carbon black; masterbatch; PET; ispersing agent; copolyester