不同TiO_2含量PET的流变性能研究

采用毛细管流变仪研究了不同二氧化钛(Ti O_2)含量的聚对苯二甲酸乙二醇酯(PET)的流变性能。结果表明:添加Ti O_2质量分数为2.4%及以下的消光PET为假塑性非牛顿流体;在280℃、285℃、290℃下消光PET在低γ下的η_a高于大有光PET,且随着Ti O_2含量的提高,η_a略有增大;在280℃、285℃、290℃下,消光PET的非牛顿指数n低于大有光PET,而在295℃时,消光PET的n高于大有光PET;在γ低于3 000 s-1时,消光PET的ΔE_η高于大有光PET,而随着γ的逐渐增大,消光PET的ΔE_η又逐渐低于大有光PET;在280℃、285℃和290℃温度下消光PET的结构粘度指数Δη高于大有光PET,295℃时低于大有光PET。

Rheological behavior of PET with different amounts of TiO2

The rheological behavior of polyethylene terephthalate ( PET) with different amounts of titanium di-oxide (TiO2) was studied by capillary rheometer. The results showed that the PET containing less than 2. 4% TiO2 belonged to non-Newtonian pseudoplastic fluid. Compared with pure PET, the PET containing TiO2 had higher shearing viscosity (ha) at low shearing rates at 280℃, 285℃, 290℃. Meanwhile, theηa slightly increased with the increase of TiO2 content. The non-Newtonian index ( n) of PET containing TiO2 was lower at 280 ℃, 285 ℃, 290 ℃, but higher at 295 ℃ than that of pure PET. When the shearing rate was lower than 3 000 s-1 , the PET containing TiO2 had higher viscous flow activation energy ( DEh ) than the pure PET; however, with the shearing rate increasing, the DEh of the former gradually became lower than the later. The structural viscosity index ( Dh) of PET containing TiO2 was higher at 280 ℃, 285 ℃, 290 ℃, but lower at 295 ℃ than that of pure PET.