硬脂酸是一种常见的长碳链的饱和脂肪酸，同时具有长碳链的亲油端和羧基的亲水端，而纳米碳酸钙表面是亲水的，所以把硬脂酸包覆在纳米碳酸钙表面，能大大的改善其亲油性，使其填充在橡胶、塑料、高级油墨、涂料中时，其大的比表面积和高比表面能有利于碳酸钙颗粒与有机高聚物分子之间的结合牢固，能使制品表面光艳和具有优异的补强性能。

Stearic acid is a common saturated fatty acid with long carbon chains, which has both the lipophilic end of the long carbon chain and the hydrophilic end of the carboxyl group. However, the surface of nano calcium carbonate is hydrophilic. Therefore, coating stearic acid on the surface of nano calcium carbonate can greatly improve its lipophilicity, making it suitable for filling in rubber, plastics, advanced inks, and coatings, Its large specific surface area and high specific surface energy are conducive to the strong bonding between calcium carbonate particles and organic polymer molecules, which can make the surface of the product shiny and have excellent reinforcement performance.

1、硬脂酸包覆改性纳米碳酸钙的机理

1. Mechanism of Stearic Acid Coated Modified Nano Calcium Carbonate

采用商业硬脂酸，在水相条件下包覆沉淀的碳酸钙，包覆之后的碳酸钙，硬脂酸的含量为3%~13.5%。采用傅里叶红外（FTIR）、热重（TG）和差示扫描量热（DSC）分析表明在碳酸钙表面没有游离的硬脂酸，只存在硬脂酸钙。发现形成的硬脂酸钙在包覆层表面是部分的化学吸附和部分的物理吸附，并且可以解决在水相条件下碳酸钙不能表面的全包覆的问题，大的包覆量为3.25%。

Using commercial stearic acid, the precipitated calcium carbonate is coated under aqueous conditions, and the content of stearic acid in the coated calcium carbonate is 3%~13.5%. Fourier transform infrared (FTIR), thermogravimetry (TG) and differential scanning calorimetry (DSC) analysis showed that there was no free stearic acid on the surface of calcium carbonate, but only calcium stearate. It was found that the formed calcium stearate exhibits partial chemical adsorption and partial physical adsorption on the surface of the coating layer, and can solve the problem of calcium carbonate not being fully coated on the surface under aqueous conditions, with a large coating amount of 3.25%.

2、长链脂肪酸对碳酸钙的影响

2. The Effect of Long Chain Fatty Acids on Calcium Carbonate

长链脂肪酸的加入不影响碳酸钙的晶型，但是影响着所生成碳酸钙粒子的形貌。当加入月桂酸时，碳酸钙粒子的分散性大大提高；当加入大量的棕榈酸和硬脂酸时，形成了微棒状结构和纺锤状结构。作者提出，在氢氧化钙和二氧化碳的碳化反应过程中，一方面碳链的长度影响了氢氧化钙悬浮液所形成胶束的形状，另一方面胶束之间的接触方式决定了后形成的碳酸钙的形貌。

The addition of long-chain fatty acids does not affect the crystal form of calcium carbonate, but it affects the morphology of the generated calcium carbonate particles. When lauric acid is added, the dispersity of calcium carbonate particles is greatly improved; When a large amount of palmitic acid and stearic acid is added, a micro rod like structure and a spindle like structure are formed. The author proposes that during the carbonization reaction between calcium hydroxide and carbon dioxide, on the one hand, the length of the carbon chain affects the shape of the micelles formed by the calcium hydroxide suspension, and on the other hand, the contact mode between the micelles determines the morphology of the resulting calcium carbonate.

3、活性纳米碳酸钙的应用特点

3. Application characteristics of active nano calcium carbonate

表面改性之后的纳米碳酸钙相比未改性的纳米碳酸钙和商业碳酸钙，能够大大的提高复合材料的拉伸强度、延伸率和耐磨性能以及阻燃性能。表面改性也能产生强粘合力，这使得聚合物链更牢固，聚合物的热稳定提高。基于这些纳米复合材料的高强度高韧性，可以用于电缆连接器、电气和照明开关设备，在航空航天领域也有重要价值。

After surface modification, nano calcium carbonate can significantly improve the tensile strength, elongation, wear resistance, and flame retardancy of composite materials compared to unmodified nano calcium carbonate and commercial calcium carbonate. Surface modification can also generate strong adhesion, which makes the polymer chain stronger and improves the thermal stability of the polymer. Based on the high strength and toughness of these nanocomposites, they can be used for cable connectors, electrical and lighting switchgear, and also have important value in the aerospace field.

硬脂酸作为一种常见的长链脂肪酸，廉价用途广泛，能够很好的改性纳米碳酸钙。作为廉价易得的填料，硬脂酸改性之后的活性纳米碳酸钙能够在众多有机体中很好的分散，并且能够提高有机体的拉伸强度、延伸率和耐磨性能以及阻燃性能等机械性能和热力学性能，所以选择硬脂酸对纳米碳酸钙进行改性，具有很好的研究和应用价值。更多相关事项就来我们网站http://qxu1539600089.my3w.com咨询吧！

Stearic acid, as a common long-chain fatty acid, is cheap and widely used, and can effectively modify nano calcium carbonate. As a cheap and easily available filler, the active nano calcium carbonate modified with stearic acid can be well dispersed in numerous organisms, and can improve the mechanical and thermodynamic properties such as tensile strength, elongation, wear resistance, and flame retardancy of the organism. Therefore, choosing stearic acid to modify nano calcium carbonate has great research and application value. For more related matters, come to our website http://qxu1539600089.my3w.com Consult!