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We report the preparation of glycidyl azide polymers (GAPs) by the reaction of a prepolymer polyepichlorohydrin (PECH) with sodium azide (NaN3) in mixture solvents of different mass ratios with ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and water without catalysts. The formation of GAP was confirmed by IR and NMR spectroscopy, and the molecular weight of the product was determined by gel permeation chromatography (GPC). The conversion of PECH was identified via quantitative 13C-NMR spectroscopy. This method avoids solvent pollution and simplifies the reaction post-processing. The reaction was monitored by IR and 13C-NMR. We concluded that the relative solubility of the reaction substrate in the mixed solvents has an important effect on the degree of the reaction. [ABSTRACT FROM AUTHOR]

In this work, a series of heptaphenyl siloxane trisilanol/polyhedral oligomeric silsesquioxane (T7-POSS) modified by polyols with different molecular weights were synthesized into liquid-like nanoparticle–organic hybrid materials using the grafted-from method. All grafted POSS nanoparticles changed from solid powders to liquid at room temperature. Polyurethane (PU) nanocomposites with POSS contents ranging from 1.75 to 9.72 wt % were prepared from these liquefied polyols-terminated POSS with polyepichlorohydrin (POSS–PECH). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the morphology of the POSS–PECH/PU nanocomposites. The results showed that the polyol-terminated POSS particles overcame the nanoagglomeration effect and evenly disperse in the polymeric matrix. The damping factor (tan δ) of resultant nanocomposites increased from 0.90 to 1.16, while the glass transition temperature decreased from 15.8 to 9.4 °C when POSS contents increased from 0 to 9.75 wt %. The gel content, tensile strength and Fourier transform infrared (FTIR) analyses demonstrated that the molecular thermal movement ability of the polyurethane (PU) matrix increased with increasing POSS hybrid content. Therefore, the improvement of the damping properties of the composites was mainly due to the friction-related losses occurring in the interface region between the nanoparticles and the matrix. [ABSTRACT FROM AUTHOR]

• Novel self-lubricated nanothickness MOF coating (SLNTMC) is developed. • SLNTMC is designed based on the synergistic effect of hydrophobic micro/nanostructures and lubricating layer. • Organosilane is covalently bound to ultrathin UiO-66-NH 2 coating. • SLNTMC shows good anti-icing performance which can be tuned by surface morphology and molecular weight of lubricating liquid. • SLNTMC exhibits long-term durability, high flexibility and transparency. In this paper, a novel self-lubricated nanothickness MOF coating (SLNTMC) with excellent and long-term anti-icing performance is designed based on the synergistic anti-icing mechanism of hydrophobic porous micro/nanostructures and lubricating layer. The organosilicone grafted thin UiO-66-NH 2 coating is prepared through a three-step reaction. SLNTMCs could reduce the ice adhesion to 9.4 kPa, and lower the freezing temperature of condensed water to -36.0 °C, due to the organosilicone layer of SLNTMC covering the ice nucleation sites on surface and reducing the water/ice adhesion, whilst combined with the porous micro/nano structures which introduce air pockets between water and surface and hinder their thermal conduction. SLNTMCs with larger MOF particle size show lower ice nucleation temperature and the organosilicone molecular weight of 4000–7700 is benefical to improve surface anti-icing performance. The SLNTMC exhibits a long-term durability, it maintains a low ice adhesion after 20 icing/de-icing cycles. Moreover, SLNTMC is a ultrathin, transparent, flexible solid thin film that could be prepared on different polymeric substrates, making them suitable for practical application having different requirements. [ABSTRACT FROM AUTHOR]