Imparting antibacterial activity, UV-protection properties and enhancing performance of casein modified polyester fabrics

Polyester fibres are extensively used in the textile industry because of their durability, low-cost, easy-care and compatibility properties. The hydrophobic nature of polyester is adversely affecting the level of comfort and restricts its use in most textile applications like sportswear, underwear, and bedding. Thus, the demands for improving polyester properties to meet market needs are gaining increased research interest. In the present work, casein was used as a surface-coating material for woven and knitted polyester fabrics to impart new desired properties. The fabrics were pretreated with sodium hydroxide followed by treating with various concentrations of casein using pad-dry-cure technique, as well the fabrics were treated with casein directly in presence of epichlorohydrin as cross-linker. The apparent viscosity of the different concentrations of the dissolved casein biopolymer was studied. The morphological structure and the surface chemical elements of the untreated and treated polyester fabrics were investigated using field emission scanning electron microscopy (FE-SEM) and dispersive X-ray spectroscopy (EDX), respectively. The base combining capacity of the untreated and treated fabrics was evaluated and compared, in addition to studying their physical and mechanical properties to evaluate their performance. Also, the antibacterial activity of the treated fabrics compared to the untreated one was investigated. The results revealed that all treated polyester fabrics exhibited better moisture regain, UPF, antistatic and antibacterial activity compared to the untreated fabrics. Woven and knitted polyester samples treated with casein only achieved higher strength properties, lower surface roughness and improved electrostatic charges. Even so, the woven samples pretreated with sodium hydroxide followed by casein had increased air permeability values, while the knitted samples showed decreased values and increased stiffness. The overall comparison between the significant properties of all treated polyester fabrics clarified that, the woven sample pretreated with 10% NaOH then 7% casein and knitted sample treated with 4% casein only achieved the best functional performance.