镧化物改性超细碳酸钙对PET非等温结晶行为的影响

EFFECT OF ULTRA-FINE CaCO_3 MODIFIED BY La^(3+) ON NON-ISOTHERMAL CRYSTALLIZATION BEHAVIOR OF PET

用DSC研究了镧化物改性超细碳酸钙与成核剂NA对PET非等温结晶行为的影响,并对其结晶成核能力进行了分析。结果表明,各成核剂均使PET的结晶温度和结晶度提高,结晶峰半峰宽变窄。非等温结晶动力学分析表明各样品的Avrami指数介于3～5,成核剂的加入使PET的结晶动力学常数增加而半结晶时间缩短。根据过冷温度和过热温度,成核剂的结晶成核能力大小顺序为UCaCO3-5La3+>NA>UCaCO3-10La3+>UCaCO3-1La3+。

Effects of ultra-fine calcium carbonate(UCaCO_3) modified by compound of Lanthanum(La^(3+)) and a type of nucleating agent(NA) on non-isothermal crystallization behavior of polyethylene terephthalate(PET) were studied by differential scanning calorimetry(DSC). The results show that compared with pure PET, nucleated PET shows a higher crystallization temperature and crystallinity, and a more narrow half-height width of crystallization peak. The study of non-isothermal crystallization kinetics shows that the Avrami index between 3~5, the crystallization kinetics parameter is increased and the half-crystallization time is shortened by nucleating agents. According to the temperature of supercooling and superheating, the order of nucleating ability of nucleating agents: UCaCO_3-5La^(3+)>NA>UCaCO_3-10La^(3+)> UCaCO_3-1La^(3+).