Effect of Polystyrene Grafting on the Glass Transition Behavior of Polystyrene-Carbon Nanotube Composites

摘要

The effect of single-walled carbon nanotubes on the glass transition of polystyrene with and without polystyrene grafting has been quantified. Three different molecular weights, 2,800, 15,000 and 50,000 g/mol, of polystyrene were grafted to the nanotubes with the weight fractions of grafted chains approximately the same. In addition, a grafting density of about a factor of 3 less was prepared for the lowest molecular weight grafted material. Composites with 50 K grafted nanotubes were statistically identical in terms of the glass transition temperature and change in heat capacity. Composites with lower molecular weight grafted nanotubes did show significant differences vs. the composites with ungrafted nanotubes, especially in terms of the change in heat capacity. Changing the grafting density for the low molecular weight material caused no change in the observed behavior.