偶联剂改性碳酸钙晶须在涂布中的应用

Surface modification of calcium carbonate whiskers with coupling agent and its application in papermaking process

为了探究晶须在造纸涂布体系中的应用,分别采用铝钛复合偶联剂和钛酸酯偶联剂改性作为功能性组分添加于纸张涂布体系中的晶须后进行性能分析,扫描电镜分析表明晶须粉体形貌没有变化,分散性得到显著改善。接触角测定表明改性后的晶须表面性能改变,由亲水性变成疏水性。将改性晶须加入纸张体系后制得造纸涂料,探究涂料的流变行为。结果表明:(1)加入改性后的晶须能显著增强涂料体系中各组分的相容性,使体系流动阻力减小,黏度降低,更便于涂布流送;(2)加入改性后晶须的纸张的抗张强度、耐破度、耐折度、白度等物理性能均有明显改善,偶联剂的改性增强了纸张纤维间的结合力。同时铝钛复合偶联剂作为复合材料的优势发挥明显,应用于纸张涂布中,比单一的钛酸酯偶联剂更能增加纸张纤维间的结合强度,涂布纸张物理性能改善更加明显。说明通过对晶须改性并应用于造纸涂料中,更进一步拓展了铝钛复合偶联剂和钛酸酯偶联剂应用范围,同时也为碳酸钙晶须更有效应用于纸张涂布中提供了依据。

To study application of calcium carbonate whiskers in papermaking process, surface modification of calcium carbonate whiskers with aluminum titanium coupling agent and titanate coupling agent was carried out, the calcium carbonate whiskers unmodified and modified were applied in paper coating. Then the physical performance of the papers was measured. It was indicated by scanning electron microscope that appearances of powder have no change, but the dispensability of powder was improved largely. The measurement of the contact angle indicated that the surface performances of powder modified change from hydrophily to hydrophobicity. The calcium carbonate whiskers were applied in paper coating to explore the rheograms of the coating color. The results indicate that the compatibility of paper coating system added with modified whiskers is improved largely, streaming resistance of system and viscosities of coating color decrease for the convenience of coating drifting; the paper coated with the coating color added modified whiskers has the better performance, including the significant improvement of the tensile strength, burst strength, folding endurance and whiteness, because the whiskers＇ modification by the coupling agent strengthened the bonding power between the fibbers. As composite material, the advantages of aluminum titanium coupling agent develop obviously, paper fiber anchoring strength is higher than only titanate coupling agent, which makes the paper physical performances improved obviously. It indicated that the application of modified whiskers with coating color in paper coating process expands the scope of aluminum titanium coupling agent and titanate coupling agent, which provide the evidences to the application of modified whiskers in paper coating process.