Modification of fabric via co-grafted with fluorine-free carbene polymer and its hydrophobicity

In this paper, by means of carbene polymerization, low surface energy polymers were covalently grafted onto the surface of cotton fabric, which successfully constructed a rough morphology in-situ and provided excellent hydrophobic properties. Firstly, the grafting site was constructed on the surface of cotton fiber, and octyl diazoacetate was synthesized as a precursor and grafted onto cotton fiber. However, due to the soft side-chain grafted polymer was film-forming, the WCA of fabric grafted with octyl diazoacetate was only 124.0 +/- 2.1 degrees. In order to construct a roughening morphology in-situ, tert-butyl diazoacetate and phenyl diazoacetate was introduced and co-grafted with octyl diazoacetate. It was found that tert-butyl diazoacetate and phenyl diazoacetate were polymerized into spherical and cubic crystals on the surface of cotton fiber, respectively. These two precursors were co-grafted with octyl diazoacetate on the surface of cotton fiber to produce a rigid polymer chain and form roughening crystal morphology. The surface morphology of the treated fiber was tested by SEM, AFM and ImageJ, it was found that different morphologies could be formed on the fiber surface when octyl diazoacetate and tert-butyl diazoacetate were co-grafted with different molar ratios. Among them, when octyl diazoacetate/tert-butyl diazoacetate(1:19)was used, the composite morphology of polymer film coated particles can be formed on the fiber surface, and the surface modification of "roughening " increased the WCA of the fabric to 143.2 +/- 1.8 degrees, which gave the fabric good hydrophobicity. When octyl diazoacetate was co-grafted with phenylethylcarbene diazoacetate at the molar ratio of 1:19, the surface of the treated fiber appeared film-like and microspheres embedded in the membrane. It is worth pointing out that the film-wrapped microsphere on the fiber surface provides a lotus leaf-like morphology. The WCA of the as-prepared fabric reached 151.2 +/- 0.8 degrees with excellent self-cleaning properties and super hydrophobicity.