Study of the UV protective and antibacterial properties of aqueous polyurethane dispersions extended with low molecular weight chitosan

- A series of low molecular weight chitosan based polyurethane dispersions (PUDs) were synthesized.
- Monomers, PU prepolymer, and final PU FTIR spectra confirmed the proposed structure.
- Application of the material on fabric samples was confirmed by SEM analysis.
- Antimicrobial and UV protective performance of treated fabrics was performed by standard methods and evaluated.
- The addition of chitosan remarkably increases antimicrobial and UV protective properties of PUs.

A series of aqueous dispersions of polyurethane (PU) and low molecular weight chitosan (CS(LMW)) has been prepared in two steps synthetic process. In first step PU prepolymer, with NCO termini were prepared by reacting isophrone diisocyanate (IPDI), poly (caprolactone) diol (CAPA, Mn 1000), and 2,2-dimethylol propionic acid (DMPA), followed by neutralization of PU prepolymer with triethylamine (TEA). In second step PU prepolymer chain was extended by low molecular weight chitosan followed by dispersion formation by adding calculated volume of water. Molecular characterization of CS(LMW)-PU finishes was done by FTIR and application on poly-cotton blended fabric samples was confirmed by scanning electron microscopy (SEM). Antimicrobial and UV protective performance of treated fabrics was performed by AATCC 100 and AATCC TM183 methods respectively. Furthermore, it shows that the addition of chitosan remarkably increases antimicrobial and UV protective properties of PUs.