【摘要】 碳纤维增强水泥基复合材料(CFRC)已成为一种很有潜力的智能材料,其制备的关键是尽可能将碳纤维均匀分散到水泥基体中,这样才能得到性能优良的CFRC复合材料。该研究探讨了制备CFRC前期阶段碳纤维分散这一关键环节中,甲基纤维素(MC)、羧甲基纤维素钠(CMC)、羟乙基纤维素(HEC)3种常用分散剂的质量分数对短碳纤维在其水溶液中分散性的影响;分析了一定温度下分散剂质量分数和溶液黏度的关系;从纤维素结构出发,解释了不同分散剂的分散效果。实验表明,采用超声波对短碳纤维进行预分散,然后加入分散剂继续超声分散,均能提高短碳纤维的分散性。短碳纤维的分散性与分散剂的种类和质量分数有关。一定温度下,分散剂质量分数相同时,分散剂对短碳纤维的分散效果为HEC>CMC>MC,HEC掺量为水泥质量的0.6%~0.8%、其水溶液质量分数为1.56%~1.77%时,短碳纤维在水溶液中呈理想分散态。更多还原

【Abstract】 Carbon fiber reinforced cement composite(CFRC) has become a potential smart material.The key process of preparing this composite is how to disperse carbon fibers evenly into cement matrix to get CFRC composite of good properties.In this study,the influence of mass fraction of three common dispersants MC(methyl cellulose),CMC(carboxymethyl cellulose sodium) and HEC(hydroxyethyl cellulose) on the dispersion of short carbon fibers in water was investigated prior to the manufacture of CFRC.The correlation between mass fraction and viscosity was discussed,and the dispersion effect was explained from the structure of dispersants.Experiments showed that pre-dispersion by ultrasonic vibration improved the dispersion of carbon fibers apparently.The dispersivity of carbon fibers was closely related to the category and mass fraction of dispersants.With same mass fraction of dispersants at a certain temperature,the dispersion effect was in the order of HEC>CMC>MC.Meanwhile,when the added amount of HEC was between 0.6% and 0.8% by weight of cement and the mass fraction of the aqueous solution was between 1.56% and 1.77%,carbon fibers dispersed most ideally in aqueous solution.更多还原