卤素吸收剂对苯甲酸钠成核PP的影响

Effect of halogen absorber on sodium benzoate nucleated PP

研究了2种卤素吸收剂对苯甲酸钠成核作用的影响。硬脂酸钙(CaSt)和合成水滑石DHT-4A均使苯甲酸钠在聚丙烯(PP)中的成核作用降低,但CaSt使成核PP性能下降更为明显,添加质量分数为0．05%的CaSt使PP的屈服拉伸强度、弯曲模量和结晶温度分别下降5．3％,11％和5．3℃。而在同样添加量时,DHT-4A对苯甲酸钠成核PP性能的影响不明显。因此,用苯甲酸钠作成核剂时,卤素吸收剂应选用DHT-4A,可以提高成核PP的综合性能。

The effect of calcium stearate （CaSt） and synthetic hydrotalcite （grade DHT-4A） as halogen absorbers on nucleation of sodium benzoate in polypropylene （PP） was studied. The presence of both CaSt and DHT-4A could militate against the nucleating power of sodium benzoate and furthermore, CaSt even caused a more obvious deterioration in mechanical properties of the nucleated PP. The addition of 0.05% mass fraction of CaSt resulted in a decrease of 5.3% in tensile strength at yield, 11% in flexural modulus and 5.3 ℃ in crystallization temperature, respectively. However, adding same dosage of DHT-4A only exerted an insignificant impact on the performance of PP nucleated with sodium benzoate. Therefore, when sodium benzoate was adopted as nucleator, DHT-4A should be selected as halogen absorber for the sake of heightening comprehensive performance of the nucleated PP.