一种水溶性石墨烯及其聚氨酯复合材料的制备与性能

Synthesis and Properties of Water Soluble Graphene and Its Application in Polyurethane Membranes

将甲苯二异氰酸酯三聚体(IL)与聚乙二醇单甲醚(MPEG)按摩尔比1∶3充分反应,制备了一种水溶性大分子单体(IL-MPEG),将其与氧化石墨烯(GO)按质量比2∶1混合后经水合肼还原制备了一种水溶性石墨烯IL-MPEG/RGO。采用红外光谱仪、拉曼光谱仪、原子力显微镜、透射电镜、扫描电镜和X射线衍射仪等对其结构、形貌和分散性进行了表征。结果发现,IL-MPEG中六元环及苯环疏水结构通过范德华作用力吸附在石墨烯表面,而聚氧乙烯(PEO)亲水链段在水相伸展为其提供水溶性。研究发现,IL-MPEG/RGO在水性聚氨酯(WPU)中具有良好的分散性,能显著改善聚氨酯膜的氧气阻隔性能,当IL-MPEG/RGO在WPU中的含量为0.5%时,氧气透过率(OTR值)低至3.6 cm^3/(m^2·d)。

A water-soluble functional monomer(IL-MPEG) was prepared from toluene diisocyanate trimer(IL) and methoxy polyethylene glycol(MPEG1500) at the mole ratio of 1∶3. Mixing it with graphene oxide at the mass ratio of 2∶1, a stable dispersible water-soluble graphene(IL-MPEG/RGO) was obtained by chemical reduction by ultrasonic treatment. The structure, morphology and dispersion of the IL-MPEG/RGO were characterized by AFM, TEM, SEM, XRD etc. The results show that the hydrophobic structures of hexagonal ring and benzene ring in IL-MPEG were adsorbed on the surface of graphene by van der Waals force while the hydrophilic segments of polyethylene oxide(PEO) provide water solubility. It is found that IL-MPEG/RGO has good dispersion in waterborne polyurethane(WPU) and significantly improves the oxygen barrier property of polyurethane membranes. When the mass fraction of IL-MPEG/RGO in WPU is 0.5%, the oxygen transmittance(OTR) is as low as 3.6 cm^3/(m^2·d).