碳酸镁晶须的反向沉淀法制备及其阻燃性能

Synthesis of Magnesium Carbonate Whisker by Reverse Precipitation Method and Its Flame Retardant Property

【目的】制备碳酸镁晶须并研究其作为填充物时对复合材料阻燃和力学性能的影响。【方法】以镁盐和碳酸钠为原料,采用反向沉淀法制备碳酸镁晶须,并考察镁盐（MgSO4·7H2 O、Mg（NO3）2·6H2 O、MgCl2·6H2 O等）、反应时间、滴液速度、表面活性剂[十二烷基硫酸钠（SDS）、十六烷基三甲基溴化铵（CTAB）、壬基酚聚氧乙烯醚（OP-10）]等因素对碳酸镁晶须形貌的影响；同时研究经钛酸酯偶联剂 NDZ-311改性后的碳酸镁晶须对高密度聚乙烯（HDPE）材料的阻燃性能和力学性能的影响。【结果】所制备的碳酸镁晶须形貌为棒状,以MgSO4·7H2O与 Na2CO3反应30 min,硫酸镁溶液滴加速率为3.5 mL·min-1时所制备的碳酸镁晶须长径比最大；表面活性剂可显著提高其长径比。经钛酸酯偶联剂 NDZ-3 1 1改性后的碳酸镁晶须可明显提高 HDPE 的阻燃性能和拉伸强度,当其添加量为高密度聚乙烯的40wt%时,复合材料的拉伸强度提高一倍。【结论】采用反向沉淀法可制备棒状碳酸镁晶须,该晶须对 HDPE具有良好的阻燃和增强性能。

Objective]Magnesium carbonate whisker was prepared,and its influence on the flame retardant and reinforcement properties of composite materials were studied when it is used as a filler.[Methods]The magnesium carbonate whisker was synthesized by reverse precipitation method,and the raw materials was magnesium salt and Na2 CO3 .The effects of some factors on the morphology of magnesium carbonate whisker were studied,including the variety of magne-sium salts （MgSO4 ·7H2 O,Mg（NO3 ）2 ·6H2 O and MgCl2 ·6H2 O）,reaction time,dropping speed and surfactants [sodium dodecyl sulfate （SDS ）,cetyl trimethyl ammonium bromide （CTAB ）,nonylphenol polyoxyethylene ether （OP-10）].Meanwhile,the flame retardant and mechanical properties of HDPE,which was filled with the magnesium carbonate whisker modified with titanate coupling agent,were also investiga-ted.[Results]The prepared magnesium carbon-ate whisker is rod-like in morphology,and the largest ratio of length to axes diameter is ob-tained when MgSO4 · 7 H2 O reacts with＆nbsp;Na2 CO3 ,and the whisker length reaches the greatest value when reaction time is 30 min.The three surfactants can greatly enhance the ratio of length to axes diameter.The addition of mag-nesium carbonate whisker modified with titanate coupling agent can obviously improve the flame retardant performance of high density polyethylene （HDPE）and tensile strength.When the content of filled whisker is 40wt% of HDPE,the tensile strength has double.[Conclusion]The rod-like magnesium carbonate whisker can be synthesized by reverse precipitation method, and has good effects on flame retardant and reinforcement on HDPE.