THE APPLICATION OF BLOCKED WATERBORNE POLYURETHANE IN COATING PROCESS
The application of blocked pre-polymer of polyurethane, i.e. imidazole-TDI-PEG (called LTP600) in coating process was investigated. The coating weight of the filter paper was 5g/m2, 10 g/m2, 15 g/m2, 20 g/m2, 30 g/m2 and 40 g/m2. The physical properties of the coated paper were tested. It was found that the treatment could enhance the paper’s physical strength. When the coating weight of the filter paper was 15 g/m2, the physical properties of the filter paper were enhanced significantly, especially the wet strength and folding resistance. Wet strength index of the paper reached 37.92N·m·g-1, 1.39 times as much as dry strength index of the original base paper. Folding number was 756, which is 54 times of the original base paper. Reaction mechanism between LTP600 and fiber was studied by the combination of chemical analysis of “methylation + alkali treatment + acetylation, FT-IR analysis, NMR analysis and scanning electron microscope observation. It was found that the blocked -NCO groups could be unblocked when coated paper was heated. The ester bonds could be formed between the unblocked -NCO and -OH in fiber. The chemical bonds were stronger than the hydrogen bonds between the fibers so that the physical strength of coated paper was enhanced.
waterborne polyurethane imidazole paper coating physical strength
Shang Wei Xie Yimin Yang Haitao
Key Laboratory of Paper Science and Technology of Ministry of Education, Shandong Institute of Light Key Laboratory of Paper Science and Technology of Ministry of Education, Shandong Institute of Light
国际会议
广州
英文
2043-2046
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）