Surface properties of cellulose modified by imidazolidinone

The influence of the modification of cellulose fibres by the imidazolidinone derivative 1,3-dimethyl-4,5-dihydroxyethylene urea (DMeDHEU) on fibre surface free energy and electrochemical potential was studied. The presence of DMeDHEU in the cellulose structure was confirmed by infrared spectral analysis. The surface free energy of untreated and treated cellulose fibres was determined from the results of thin-layer wicking, where the rate of liquid penetration into the cellulose fabric was measured. Using the van Oss-Chaudhury-Good theoretical approach, apolar, γ _S ^LW , polar electron-acceptor, γ _S ⁺, and electron-donor, γ _S ⁻, components of the surface free energy were calculated. The electrokinetic potential was determined from the results of steaming potential measurements. The results revealed that the incorporation of DMeDHEU into the cellulose structure lead to a decrease in the value of γ _S ⁻, whereas the values of γ _S ^LW and γ _S ⁺ remained almost unchanged. Despite their decreased γ _S ⁻ value, the treated cellulose fibres still represent a monopolar solid with a strongly expressed electron-donor component. The values of ΔG _iw and ΔG _iwi suggested that both untreated and treated cellulose samples could be considered hydrophilic substrates. The results of the electrokinetic potential measurements showed that the consumption of cellulose hydroxyl groups in the crosslinking reaction with DMeDHEU did not decrease the electrokinetic properties of the cellulose surface.