In this work polyacrylonitrile (PAN)/single wall carbon nanotube (SWNT) composites with 50 wt% SWNT loading were studied. A previously studied solvent-based phase separation process was used to enhance PAN-SWNT crystallization conditions and interphase formation within the composites. Two types of SWNT species were used here to produce two composites materials with well-ordered PAN-SWNT interphase structures. All precursor composite films were stabilized and subsequently carbonized at temperatures ranging from 900 to 1500 degrees C under various carbonization times. Wide-angle X-ray diffraction and electron microscopy were used to analyze the structural change in these precursors during carbonization. It was found that ordered graphitic structures were formed using specific temperature/time conditions as early as 900 degrees C. This low-temperature graphitic structure can be tracked directly to the PAN interphase structure within the precursors. This paper discusses the linkage between precursor PAN-SWNT interphase formation and subsequent low-temperature graphitic formation. (C) 2018 Elsevier Ltd. All rights reserved.