A Novel Cyclic Polysiloxane Linked by Guanidyl Groups Used as Flame Retardant and Antimicrobial Agent on Cotton Fabrics

A novel flame retardant and antibacterial agent, (tetramethylcyclosiloxyl-piperazin) tetra guanidine (GNCTSi) used for cotton fabrics was successfully synthesized. The limiting oxygen index (LOI) value of cotton fabric treated with 250 g/l GNCTSi reached to 30.1 %. The vertical burning test results showed that the char length of the treated cotton fabric was 6.5 cm and have no after-flame and no after-glow. Compared with untreated cotton fabric, the treated cotton fabric showed better flame retardancy and higher residue rate by themogravimetric analysis (TG). The GNCTSi exists on the treated cotton fabric was observed and the residues of cotton fabric after combustion had a homogeneous surface without break by scanning electron microscopy (SEM). The treated cotton fabric showed good antibacterial activity against E. coli and S. aureus and the inhibition zone were 2.5 mm and 2.3 mm, respectively. After repeated washing, the LOI of cotton fabric is still higher than 26 %.