Abstract:

Using amphoteric aluminates coupling agent DL-411 (ACA) as the modifier, potassium bicarbonate (PB) was modified by ethanol dissolution followed by evaporation and high-temperature melting methods, and the high-temperature potassium bicarbonate foaming agent (ACA@PB) prepared was applied to the production process of polypropylene microfoam materials to meet the functionalization needs of lightweight and high-performance polypropylene microfoam materials. And the thermal decomposition properties, preparation conditions and microcosmic morphology of ACA@PB were investigated by using thermogravimetric (TG), scanning electron microscopy (SEM) and infrared (FTIR) characterization methods. The results showed that when the mass ratio of ACA and PB was 3∶5, the thermal decomposition temperature of PB was increased from 155.9℃ to 203.9℃, and the decomposition temperature interval was shortened from 78.0℃ to 40.0℃; When the addition amount of ACA@PB was 4%, the tensile strength of polypropylene microfoam was 30.30MPa, the elasticity modulus was 1.73GPa, and elongation at break was 9.67%, the unnotched impact strength of simply supported beam was 63.07kJ/m², which was in line with the processing and application of industrialised polypropylene microfoam.

Key words: high-temperature potassium bicarbonate foaming agent, aluminate coupling agent DL-411, thermal decomposition, dispersibility, polypropylene

摘要：

为提高碳酸氢钾的热分解温度，使其满足轻量化高性能聚丙烯微发泡材料的工业化需求，以两性物质铝酸酯偶联剂DL-411（ACA）为改性剂，采用乙醇溶解蒸发法和高温熔融法改性碳酸氢钾（PB），制备高温型碳酸氢钾发泡剂（ACA@PB），并将其应用在聚丙烯微发泡材料加工生产过程中；利用热重（TG）、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）等表征手段，研究高温熔融法改性碳酸氢钾的热分解性能、较佳制备条件和微观形貌；考察ACA@PB添加量对聚丙烯微发泡材料泡孔分布和力学性能的影响。结果表明，当铝酸酯偶联剂DL-411和碳酸氢钾的质量比为3∶5时，碳酸氢钾的初始热分解温度T_{\mathrm{0}}由155.9℃提高至203.9℃，分解温度区间\mathrm{\Delta }T由78.0℃缩短至40.0℃；当ACA@PB添加量为4%时，聚丙烯微发泡材料拉伸强度为30.30MPa、弹性模量为1.73GPa、断裂伸长率为9.67%、简支梁无缺口抗冲击强度为63.07kJ/m²，符合工业化聚丙烯微发泡材料的加工应用要求。

关键词: 高温型碳酸氢钾发泡剂, 铝酸酯偶联剂DL-411, 热分解, 分散性, 聚丙烯