涂料用贝壳粉体的复合改性

Composite modification of shell powder for paints

以废弃贻贝壳为原料制得贝壳粉体,并通过1 mol/L稀磷酸酸蚀,制得改性粉体,考察了腐蚀比例对粉体分散性能的影响。当贝壳粉体中碳酸钙被腐蚀的比例为10%时(所得样品记为10%c-bkf),沉降体积最大,吸油量和比表面积分别为0.4019 g·g−1和17.78 m2/g。对10%c-bkf分别添加2.5%的硬脂酸钙(CS)、硬脂酸(SA)、螯合型钛酸酯偶联剂(UP-311)和铝酸酯偶联剂(UP-801)作进一步改性,发现硬脂酸改性后的粉体具有良好的疏水亲油性能,分散性增强。用复合改性的贝壳粉体部分替代环氧富锌涂料中的锌粉,并与碳酸钙进行对比。结果表明,改性贝壳粉体能够在一定程度上替代传统的碳酸钙粉体应用在涂料中,有利于实现废弃贝壳的再利用。

A shell powder was prepared by wasted Mytilus edulis shells,and then modified by etching in 1 mol/L diluted phosphoric acid solution.The effect of corrosion ratio of the shell powder on its dispersibility was studied.The shell powder with 10%of calcium carbonate corroded,which was coded as 10%c-bkf,had the maximum sedimentation volume,an oil absorption of 0.4019 g·g−1,and a specific surface area of 17.78 m2/g.The 10%c-bkf was further modified with 2.5%of four different organic modifiers respectively,namely calcium stearate(CS),stearic acid(SA),chelating titanate coupling agent(UP-311),and aluminate coupling agent(UP-801).It was found that the shell powder had good hydrophobicity and oleophilicity and even better dispersibility after modification by stearic acid.The composite modified shell powder was used to replace part of zinc pigment in a zinc-rich epoxy paint and compared with calcium carbonate.The results showed that the traditional calcium carbonate could be replaced by the composite modified shell powder to a certain extent in paints,which would be helpful for the reuse of wasted shells.