Dynamic mechanical properties of a TiO2‐filled crosslinked epoxy resin from 20–90°C.

Dynamic mechanical measurements were made with a torsional pendulum of a TiO filled epoxy polymer (crosslinked with hexamethylene diamine) over a temperature range from 20–90°C., at filler concentrations of 0–40 wt.‐%. The second‐order transition temperature (Tg) was raised as the filler content increased. The behavior of TiO2 filler results in a long‐range immobilization of the highly crosslinked system with resultant increases in shear modulus (higher G′) as well as decreased capacity for energy dissipation (lower damping factor). The out‐of‐phase modulus (G″) increased with filler content as well. The magnitudes of the slope parameters Hr (representing G′ data above Tg) and Hg (representing G′ data below Tg) decreased with greater filler content. The possibility is set forth that the TiO2 filler causes a different distribution of mobility around the nitrogen junction as well as a change in the effective number of CH2 units between crosslinks.