Nanomechanical characterisation of a water-repelling terpolymer coating of cellulosic fibres

TL;DR

This study evaluates a terpolymer coating's effectiveness in enhancing water resistance and hydrophobicity of cellulosic fibres, using multiple microscopy and spectroscopy techniques to analyze coating distribution and nanomechanical properties.

Contribution

It provides a comprehensive nanomechanical and microscopic analysis of a novel water-repelling terpolymer coating on cellulose fibres, linking macroscopic hydrophobicity to microscopic coating properties.

Findings

Coating improves hydrophobicity of fibres.

Water uptake alters local nanomechanical properties.

Coating distribution is heterogeneous on fibres.

Abstract

Polymer coatings on cellulosic fibres are widely used to enhance the natural fibre properties by improving, for example, the hydrophobicity and wet strength. Here, we investigate the effects of a terpolymer P(S-co-MABP-co-PyMA) coating on cotton linters and eucalyptus fibres to improve the resistance of cellulose fibres against wetness. Coated and uncoated fibres were characterised by using scanning electron microscopy, contact angle measurements, Raman spectroscopy and atomic force microscopy with the objective of correlating macroscopic properties such as the hydrophobicity of the fleece with microscopic properties such as the coating distribution and local nanomechanics. The scanning electron and fluorescence microscopy results revealed the distribution of the coating on the paper fleeces and fibres. Contact angle measurements proved the hydrophobic character of the coated fleece, which was also confirmed by Raman spectroscopy measurements that investigated the water uptake in single fibres. The water uptake also induced a change in the local mechanical properties, as measured by atomic force microscopy. These results verify the basic functionality of the hydrophobic coating on fibres and paper fleeces but call into question the homogeneity of the coating.