不同软硬段比例的封闭型水性聚氨酯对纸张性能的影响

Synthesis of Polyurethanes from Different PEG and Their Application in Enhancement of Paper Properties

中文关键词:  聚氨酯  PEG  TDI  纸张性能

Key Words:polyurethane  PEG  TDI  paper properties

中文摘要:

      研究了不同软硬段比例的聚氨酯预聚体对纸张性能的影响，探讨了不同分子质量的聚乙二醇（PEG）作为扩链剂对合成聚氨酯预聚体的影响。分别合成了由咪唑、甲苯-2，4-二异氰酸酯（TDI）和6种聚乙二醇（PEG）同系物(包括PEG200、PEG400、PEG600、PEG800、PEG1000、PEG1500)形成的封闭型水性聚氨酯预聚体，并将其用于滤纸涂布。讨论了预聚体表面涂布量为3、5、8、10 g/m2时，滤纸各项物理性能的变化。研究结果表明，软硬段比例的变化对聚氨酯化的滤纸湿抗张指数、耐折度、撕裂指数影响规律性不明显，但是随软段比例上升，滤纸的抗张指数和挺度逐渐减小。聚氨酯化后的滤纸各项物理性能均有明显增强，以咪唑-TDI-PEG400预聚体为例，在涂布量为8 g/m2时，处理后滤纸的湿抗张指数、抗张指数、耐折度、撕裂指数、挺度分别提高到原滤纸的10.7倍、2.1倍、53.6倍、1.5倍、1.3倍。

Abstract:

      In order to understand the influence of pre-polymers of polyurethane which have different hard segments/soft segments ratio on paper properties, the effect of molecule weight of polyethylene glycol was investigated. A series of pre-polymers were synthesized with imidazole, 2,4-diisocyanate (TDI) and six homologues of PEG, including PEG200, PEG400, PEG600, PEG800, PEG1000 and PEG1500. The application of the polyurethanes in paper coating was also investigated. Coating weights were 3 g/m2, 5 g/m2, 8 g/m2 and 10 g/m2 respectively. The physical properties of the coated paper were tested. It was found that different hard segments/soft segments ratio did not significantly affect wet tensile index, tear index and folding endurance of the paper. With the increase of the soft segment ratio, the dry tensile index and the stiffness decrease. The surface treatment can enhance the physical strength of paper significantly. Take imidazole-TDI-PEG (LTP400) as example, when the coating weight of LTP400 was 8 g/m2, the wet tensile index of the treated paper was increased by 10.7 times. Dry tensile index of the paper increased by 2.1 times. The folding endurance increased by 53.6 times. Moreover, the tear index and stiffness were also increased by 1.5 times and 1.3 times respectively.