Cation exchange finishing of nonwoven polyester with polycarboxylic acids and cyclodextrins

Abstract

We describe a chemical method for the finishing of polyester nonwoven fabrics that aimed to obtain ion exchange textiles. This approach was based on the use of polycarboxylic acids (PCA) and cyclodextrins as carbohydrate compounds and finishing agents, respectively. It was observed that the reaction between these reactants yielded a crosslinked polymer that was physically anchored onto the fibers. This polymer can be considered as a resin issued from the esterification between the COOH groups of the PCA with the OH groups of the carbohydrate. As the esterification reaction was not complete, many free carboxylic groups remained on the surface of the coating polymer. This feature offered the ion exchange properties to the textile support. In this article, we described the pad-dry-cure process and showed the influence of the curing parameters (time and temperature), the nature, and the concentration of the components and the pH of the impregnating bath. The grafting rate (in wt %) and the ion exchange capacity (IEC) were observed in parallel. First, it was observed that the best IEC capacity (that could reach 1 mmol/g) was obtained when an ideal compromise was applied between time and temperature of curing. We also evidenced that IEC depended on the nature and on the concentration of the PCA (chosen among citric acid, 1,2,3,4-butanetetracarboxylic acid, and polyacrylic acid) and on the pH of the impregnating bath. Finally, it was observed that cyclodextrins were more appropriate than starch as finishing coreactants.

Removal of heavy metals from aqueous media by cation exchange nonwoven PET coated with β-cyclodextrin-polycarboxylic moieties

“…Besides, bCD is a cyclic polysaccharide, with a high number of hydroxyl groups and its rigidity is favorable for a good and stable grafting ratio via esterification with PCA. A previous comparison demonstrated that bCD as polyol was more appropriate than starch (linear polysaccharide) in term of free carboxylic functions in the frame of this study [7]. Finally, the preparation used is simple (one step), ecologic (water as reaction medium) and of very low cost, and so in agreement with remediation technics.…”

“…1A). The description of the synthesis was developed in a previous paper [7]. The reaction consisted of a crosslinking polycondensation between a PCA and a bCD mixture previously impregnated onto the fabric in a padding step.…”

“…In previous papers, was detailed the elaboration of a new family of cationic exchange textile (CET) based on the coating of a polymer issued from of b-Cyclodextrin (bCD) and a polycarboxylic acid (PCA) onto poly(ethyleneterephtalate) (PET) fabrics [6,7]. The originality and applications of our materials are numerous due to their double functionality:…”

Prolonged local antibiotics delivery from hydroxyapatite functionalised with cyclodextrin polymers

“…Thus, this cyclodextrin polymer layer could act as a degradable diffusion barrier for the guest drug molecules and sustain the drug release. Besides, the macromolecular structure of the poly(BTCA-HPbCD) applied in the present study also supports carboxylate groups that are capable of forming complementary interactions to cavities with the drugs, through acid-base interactions [34]. For that reason, biomaterials devices functionalized with this type of CD polymers can interfere through specific (inclusion complexes) and nonspecific interactions (acid-base, hydrogen bonding) with the drugs.…”

New crosslinked cast films based on poly(vinyl alcohol): Preparation and physico-chemical properties

“…This quantification was undertaken by Ion Exchange Capacity (IEC) method through pH-metric titration using calcium acetate [21]. Each sample was dried 16 hours at 60°C before titration.…”