不同TiO_2含量PET的流变性能研究

Rheological behavior of PET with different amounts of TiO_2

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。

The rheological behavior of polyethylene terephthalate（ PET） with different amounts of titanium dioxide（ Ti O2） was studied by capillary rheometer. The results showed that the PET containing less than 2. 4% Ti O2 belonged to non- Newtonian pseudoplastic fluid. Compared with pure PET,the PET containing Ti O2 had higher shearing viscosity（ ηa） at low shearing rates at 280 ℃,285 ℃,290 ℃. Meanwhile,the ηa slightly increased with the increase of Ti O2 content. The non- Newtonian index（ n） of PET containing Ti O2 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 Ti O2 had higher viscous flow activation energy（ ΔEη） than the pure PET; however,with the shearing rate increasing,the ΔEηof the former gradually became lower than the later. The structural viscosity index（ Δη） of PET containing Ti O2 was higher at 280 ℃,285 ℃,290 ℃,but lower at 295 ℃ than that of pure PET.