Abstract
This study investigates the effect of static magnetic field exposure (~0.07 T, 30 min) during curing (TDC) and after full cure (TAC) on an unfilled epoxy resin, compared against untreated (UTS) and thermally treated (HTS) controls. Characterisation via modulated DSC, ATR-FTIR, TGA, and DMA revealed that chemical structure (FTIR) and thermal stability (TGA) remained unaffected. However, glass transition temperature (Tg) exhibited strong process-dependent variations. Calorimetric Tg ranged from 69.6 °C (TDC) to 74.4 °C (TAC) versus 72.9 °C (control) (p = 0.0007). Viscoelastic Tg (tan delta peak) peaked at 102.8 °C for TDC and dropped to 88.0 °C for TAC (F(3,8) = 94.4, p < 0.001), while storage modulus showed no significant change (p = 0.170). Because HTS controls did not replicate this response, the shift in Tg is attributed to spatially non-uniform thermal history during exposure rather than direct diamagnetic molecular alignment. ARTICLE HISTORY