摘要
对纸浆纤维进行羧甲基化学改性并结合高压均质处理,制得羧甲基改性纳米纤维素(NFC),探究了羧甲基改性NFC的性能及其对颜料分散稳定性、低固含量涂料流变性的影响。结果表明,随着羧甲基取代度提高,改性NFC尺寸减小、电负性增强;其溶液具有"剪切稀化"特征,即浓度越高、黏度系数越大。颜料分散性研究结果表明,颜料分散液的黏度随羧甲基改性NFC添加量增加而增大、随羧甲基取代度提高而下降;提高NFC的羧甲基取代度及增加其添加量可提高颜料分散液的悬浮体积百分比,改善颜料分散液的稳定性。对涂料性能的研究发现,提高NFC的羧甲基取代度,涂料的假塑性逐步减弱、黏度也随之降低,在一定程度上对涂料的流变起到了调节作用。另外,当NFC的羧甲基取代度为0.4时,涂料保水值下降幅度达67.8%,保水性能得到极大改善。
The nanofibrillated cellulose( NFC) with different substitution degrees of carboxymethyl were prepared from pulp fiber by carboxymethyl chemical modification treatment. The performance of modified NFC and its influence on the dispersion stability of pigment and the rheological regulation of low-solid coating were analyzed. The results showed that the size of modified NFC tended to decrease and the electronegativity increased with the increase of the substitution degree of carboxymethyl. Modified NFC solution had the characteristics of shear thinning and the higher the concentration the bigger the viscosity coefficient. Research on the dispersibility of the pigment showed that the viscosity of the pigment dispersion increased with the increase of modified NFC content,and decreased with the increase of substitution degree. The increase of modified NFC content and the substitution degree both increased the percentage of suspension of pigment dispersion and improved the stability of the pigment dispersion. The study of coating properties showed that when the substitution degree was 0. 4,the water retention value of coating decreased by 67. 8%,and the water retention property of coating was greatly improved. With the increase of substitution degree,the pseudoplasticity of the coating weakened and the viscosity decreased,so it played a role in regulating the rheology of the coating to a certain extent.
出处
《中国造纸学报》
CAS
CSCD
北大核心
2017年第4期16-21,共6页
Transactions of China Pulp and Paper
基金
国家自然科学基金项目(31470599)
江苏省高校优势学科建设项目(PAPD)
关键词
羧甲基改性
纳米纤维素
颜料
分散性
涂料
carboxymethyl modification
nanofibrillated cellulose
pigment dispersion
coating
