In this study, titanium dioxide (TiO 2 ) or nano titanium dioxide (nano-TiO 2 ) was used as a cocatalyst in the flame-retardant (FR) formulation of N-methylol dimethylphosphonopropionamide (Pyrovatex CP New, FR), melamine resin [Knittex CHN, crosslinking agent (CL)], and phosphoric acid (PA) for cotton fabrics to improve the treatment effectiveness and minimize the side effects of the treatment. For FR-treated cotton fabrics, the flame extinguished right after removal of the ignition source with no flame spreading. However, after neutralization and/or home laundering, FR-CL-treated specimens failed the flammability test, whereas the opposite results were obtained from FR-CL-PA-treated specimens. A noticeable result was that the TiO 2 /nano-TiO 2 cocatalyst had a significant effect on decreasing the flame-spread rate. Thermal analysis found that the FR-treated specimens without wet posttreatment showed two endothermic peaks representing the phosphorylation of cellulose and acid-catalyzed dehydration. In addition, the treated fabrics showed some new characteristic peaks in their chemical structures; these were interpreted as carbonyl bands, CH 2 rocking bands, and CH 3 asymmetric and CH 2 symmetric stretching. The surface morphology of the FR-CL-PAtreated cotton specimens showed a roughened and wrinkled fabric surface with a high deposition of the finishing agent that had a lower breaking load and tearing strength, which resulted from the side effects of the CL used. However, the addition of a TiO 2 or nano-TiO 2 cocatalyst could compensate for the reduction in the tensile strength.

Fabrics treated with dimethyloldihydroxylethyleneurea (DMDHEU) are susceptible to formaldehyde release. High concentrations of formaldehyde have been reported to cause cancer in animal studies. Due to the toxicity of DMDHEU, the polycarboxylic acid class of non-formaldehyde crosslinking agents used for wrinkle-resistant treatment has been introduced. Among various researches, 1,2,3,4-butanetetracarboxylic acid (BTCA) is a desirable reactant when catalysed with sodium hypophosphite (SHP). The characteristics of TiO 2 or nano-TiO2, acting as a co-catalyst in a BTCA wrinkle-resistant finishing system are examined in this study. Surface morphology and molecular structure of cotton specimens together with the wrinkle-resistant, UV protection, yellowing, tensile and tearing properties of the treated specimens are also evaluated.

An organic phosphorus compound (flame retardant agent, FR) in combination with a melamine resin (crosslinking agent, CL), phosphoric acid (catalyst, PA) and zinc oxide (co-catalyst, ZnO/ nano-ZnO) imparted effective and durable flame retardant properties. Also, atmospheric pressure plasma jet was applied as pre-treatment to improve post-finishing (flame retardant finishing) on cotton fabrics. In the present paper, surface morphology, chemical structure analysis, combustibility and mechanical properties of plasma pre-treated cotton fabrics subjected to flame-retardant treatment were investigated. Surface morphology of treated cotton specimens showed roughened and wrinkled fabric surface with high deposition of the flame retardant finishing agent, which was caused by the plasma etching effect and attack of acidic FR. The FTIR-ATR spectra for the treated cotton specimens showed some new characteristic peaks in chemical structure, interpreted as carbonyl bands, OH stretching vibration, COO -stretching vibration, CH 2 rocking band and CH 3 asymmetric and CH 2 symmetric stretching. Moreover, FR-CL-PA-treated specimens showed remarkable flame-retardant property, which was further improved by the plasma pre-treatment and ZnO/ nano-ZnO co-catalyst. However, flame-retardanttreated cotton specimens had poor mechanical strength when compared with control sample, resulting from side effects of the crosslinking agent used, while plasma pre-treatment and ZnO/nano-ZnO co-catalyst may compensate for the reduction in tensile and tearing strength caused by flame-retardant agents.

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