焙烧还原条件下硬脂酸钠改性水滑石的制备及应用

Preparation and Application of Sodium Stearate Modified Hydrotalcite Based on Calcination Reduction Conditions as Thermal Stabilizer

以镁铝碳酸根型水滑石MgAl-CO_(3) -LDHs(LDHs)为前驱体,硬脂酸钠(NaSt)为改性剂,通过焙烧还原法在硬脂酸钠的溶液中制备硬脂酸钠改性水滑石LDHs-NaSt,采用X射线衍射仪(XRD)、傅里叶转变红外光谱仪(FTIR)和扫描电镜(SEM)对结构进行表征,并研究不同改性剂加入量条件下得到的改性水滑石对聚氯乙烯(PVC)热稳定性能的影响。结果表明,在氮气保护下,焙烧后的水滑石可以成功复原,硬脂酸钠对LDHs的改性为表面改性,但影响复原水滑石的结晶度。改性水滑石可以改善PVC的初期着色性和长期热稳定性,随着改性剂浓度的增大,当NaSt与LDHs质量比为1∶4时,静态热老化时间可以达到370 min,比未改性水滑石热稳定性能提升了61%。

The sodium stearate modified hydrotalcite(LDHs-NaSt)was prepared in sodium stearate solution byroasting reduction method with MgAl-CO;-LDHs(LDHs)as theprecursor and sodium stearate as the modifier.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)andscanning electron microscope(SEM)were employed to characterize the structures of the LDHs-NaSt.The effects of LDHs-NaSt obtained from different amounts of the modifier on the thermal stability of polyvinyl chloride(PVC)composites were then investigated.The results show that the calcined LDH scould be successfully recovered by the modification of sodium stearate atnitrogen atmosphere.As the concentration of the modifier increases, both the initial coloration and long-term thermal stability of PVC could improve significantly.When the mass ratio of NaSt to LDHs is 1∶4,the static heat aging time could reach 370 min, comparing with unmodified hydrotalcite, the performance was improved by 61%.