Durable press finish of cotton via dual curing using UV light and heat

Continuous photografting/crosslinking of polyethyleneglycol dimethacrylate oligomers onto cotton using a water-soluble benzophenone photoinitiator was investigated. Photografting increased with increasing irradiation dose, oligomer concentration and photoinitiator concentration. Maximum grafting efficiency of DM 400 and 600 were 83% and 79%, respectively. The photografting increased the wrinkle resistance of cotton implying surface crosslinking of cotton. Both surface crosslinking and bulk crosslinking of cotton were accomplished via dual curing of a mixed formulation containing both a thermally curable component (BTCA/SHP) and a UV-curable component. The wrinkle resistance of the crosslinked cotton was found to be higher when cured by thermal curing after UV curing rather than by UV curing after thermal curing due to the facile post-polymerization of the UV active component. The presence of crosslinks in the dually crosslinked cotton was verified with FT-IR and thermogravimetric analysis.     

Hydrophilic modification of PET fabric via continuous photografting of acrylic acid (AA) and hydroxyethyl methacrylate (HEMA)

Poly(acrylic acid) and poly(hydroxyethyl methacrylate) were introduced onto PET fabrics by UV-induced photografting to improve its hydrophilicity. Several factors affecting the photografting were studied including irradiation energy, monomer, and photoinitiator (PI) concentrations. ATR and ESCA analyses proved successful grafting of the two monomers onto PET. Morphology of fabric surface was examined using FE-SEM. Both zeta potential and water wetting time of the grafted PET fabrics decreased with increasing grafting yield. Also cationic dyeability of the grafted PET fabrics increased because of the increased electrostatic interactions between the anionic dyeing sites and cationic dyes.     

Continuous photografting of HEMA onto polypropylene fabrics with benzophenone Photoinitiator

Continuous photografting onto polypropylene fabrics in the absence of inert gases was carried out to improve hydrophilic property of PP fabrics, which was padded with a formulated solution of 2-hydroxyethyl methacrylate(HEMA) and benzophenone as a monomer and a photoinitiator, respectively. The grafting yield increased with increases in benzophenone concentration up to 30 % on the weight of the monomer and UV energy up to of 38 J/cm², while 30 % HEMA concentration was optimal for the grafting efficiency. The physicochemical properties of the grafted PP fabrics were monitored by FT-IR, SEM, zeta potential, and dyeability to a cationic dye. The grafting increased O_1s/C_1s content and remarkably produced more negative zeta potentials compared with the pristine PP fabric. Also the grafted PP showed the increased dyeability to cationic dyes with increasing graft yield resulting from the enhanced electrostatic interaction between the dyes and negatively charged surface of the grafted PP fiber. In addition, improved hydrophilic property of grafted PP fabrics was ascertained by more rapid water wetting time and higher water absorbency.