It has been a real challenge to form carbon nanotube (CNT)/polymer composites where CNTs are well-dispersed in the polymer matrix and the interactions between CNTs and polymers are effectively strong. In this paper, we applied surface-initiated, ring-opening polymerization (SI-ROP) of p-dioxanone (PDX) to shortened single-walled carbon nanotubes (s-SWCNTs) and successfully formed s-SWCNT/PPDX composites (see Figure). Due to intimate interactions between s-SWCNTs and PPDX, we observed dramatic changes in PPDX properties upon the formation of the composites: 10%-weight-loss-temperature of PPDX increased by 20 degreesC (measured by thermogravimetric analysis) and the patterns of T-g and T-m were greatly altered. We did not observe any noticeable peaks from the composite up to 120 degreesC in differential scanning calorimetry (DSC), while DSC data of PPDX itself showed T-g and T-m at -13.4 and 103 degreesC respectively.