铝酸酯偶联剂湿法表面改性三氧化二锑及其在阻燃复合材料中的应用

Surface Modification of Antimony Trioxide with Aluminate Coupling Agent and Its Application in Flame Retardant Composites

为提升三氧化二锑(Sb_(2)O_(3))在聚丙烯(PP)中的相容性、分散性和阻燃效果,工业上常利用表面改性剂对Sb_(2)O_(3)进行改性处理。研究采用铝酸酯偶联剂DL-411对Sb_(2)O_(3)进行湿法表面改性,实验考察改性Sb_(2)O_(3)的浆液pH值、铝酸酯偶联剂DL-411用量、改性时间、改性温度等因素对改性后Sb_(2)O_(3)(Al-Sb_(2)O_(3))的水接触角和Al-Sb_(2)O_(3)/液体石蜡悬浮液黏度的影响;利用傅里叶变换红外光谱仪(FTIR)对改性前后的Sb_(2)O_(3)与铝酸酯偶联剂DL-411进行表征。确定改性的较优工艺条件为pH值9、铝酸酯偶联剂DL-411质量分数1.5%、改性时间5 min、改性温度30℃。将上述条件下得到的Al-Sb_(2)O_(3)与十溴二苯乙烷(DBDPE)复配为阻燃剂,在质量分数25%的添加量下与PP熔融共混制得复合阻燃材料,测试其阻燃及力学性能和熔体流动速率,用热重分析仪(TG)和扫描电子显微镜(SEM)表征其热稳定性以及微观形貌。相比于同样添加量的PP/SbBr复合阻燃材料,PP/Al-SbBr复合阻燃材料的阻燃及力学性能显著提升。结果表明:调整适宜pH值后,在接近室温的环境和较短的改性时间下,用铝酸酯偶联剂DL-411改性的Sb_(2)O_(3)也可以较好地提升复合材料的阻燃性能并减少力学性能的劣化。

To enhance the compatibility,dispersibility,and flame retardant effect of antimony trioxide(Sb_(2)O_(3))in polypropylene(PP),Sb_(2)O_(3)is often modified by surface modifiers in industry.This study employed the aluminate coupling agent DL-411 for the wet surface modification of Sb_(2)O_(3).The experiments investigated the effects of slurry pH,DL-411 dosage,modification time,and modification temperature on the water contact angle of modified Sb_(2)O_(3)(Al-Sb_(2)O_(3))and the viscosity of Al-Sb_(2)O_(3)/liquid paraffin suspension.Fourier transform infrared spectrometer(FTIR)characterization was conducted on Sb_(2)O_(3)before and after modification with aluminate coupling agent DL-411.The optimized conditions for the modification were determined as follows:pH value9,DL-411 mass fraction of 1.5%,modification time of 5 min,and modification temperature of 30℃.The obtained Al-Sb_(2)O_(3),compounded with decabromodiphenyl ethane(DBDPE)as a flame retardant,was melt-blended with PP at a 25%mass fraction.The composite flame retardant material was tested for flame retardancy,mechanical properties,and melt flow rate.A thermogravimetric analyzer(TGA)and a scanning electron microscope(SEM)were used to characterize its thermal stability and microstructure.The flame retardancy and mechanical properties of PP/Al-SbBr composite flame retardant material were significantly improved compared to the same loading of PP/SbBr composite flame retardant material.The findings indicate that adjusting the pH value to an appropriate level allows the aluminate coupling agent DL-411 to effectively enhance the flame retardancy of Sb_(2)O_(3)-modified composites with reduced degradation of mechanical properties,even in an environment close to room temperature and with a relatively short modification time.