Functional soil release polymers for cellulosic surfaces

Abstract

Soil release polymers (SRPs) are additives components of washing detergents for synthetic fibres, as they are effective in removing stains from the fabric surface and in preventing re-deposition of the stain during a wash cycle. Currently, there are no SRPs which can be used to efficiently perform the same function for natural cellulose based textiles. In this work, the synthesis of functional carbohydrate-based materials for application as potential SRPs for cellulosic surfaces was discussed. Two strategies were developed, exploiting the affinity of polysaccharides to adsorb over cellulose surfaces. The first strategy involved the synthesis of a co-polymer between poly(ethylene glycol diacrylate) (PEGDA), ethylenediamine and maltose, through a three step procedure. During the first step, the co-polymer backbone was synthesised through the co-polymerisation of PEGDA with N-Boc-ethylenediamine in bulk at room temperature. Then, the second amine functionality was de-protected and reacted with maltose to yield the desired co-polymer. The structure was confirmed through 1H and 13C NMR spectroscopy in solution, and through diffusion studies. The second strategy aimed to tune the strong affinity of carboxymethyl cellulose (CMC) for cellulose surfaces through grafting of poly(ethylene glycol) (PEG) chains. A variety of co-polymers were synthesised comprising different proportions of PEG bound. The co-polymers were characterised through a series of techniques, such as 13C solid state NMR, 1H gel state NMR, pulse field gradient NMR spectroscopy (PFG NMR) and size exclusion chromatography (SEC) in DMF. The potential of the co-polymers for application as SRPs was evaluated through soil release and whiteness tests. Furthermore, a preliminary study on the adsorption of two fluorescently labelled CMC-g-PEG co-polymers over cotton surfaces was conducted by means of fluorescence measurement.