Cellulose Thiocarbonate-Potassium Bromate Redox System-Initiated Graft Copolymerisation of Acrylic Esters on to Cotton Fabric

Abstract

Graft copolymerisation of 2,3-epoxypropyl methacrylate (EPMA) on to cotton-cellulose, in the fabric form, was carried out using a cellulose thiocarbonate-KB_rO₃ redox initiation system. Effects of the concentrations of KBrO₃ (initiator) and monomer, the pH of polymerization medium, grafting time and temperature were studied. The results revealed that the graft yield increased with increasing EPMA concentration within the range studied (from 10% to 160%). The optimal grafting conditions for other factors consisted of: [KBrO3], 10 g/1; pH of polymerization medium, 2.5; grafting temperature, 40°C and grafting time, 40 min. with optimum material to liquor ratio 1:30. On the basis of its efficiency as an oil repellent compound 1,1-dihydroperfluoroheptyl methacrylate (PFHMA) was combined with EPMA, in various ratios to promote grafting onto the cotton fabric under the aforementioned optimal conditions. The oil-repellency of the EPMA/PFHMA grafted fabric was then examined. The oil repellency property was found to rely essentially on the percent PFHMA in the total graft obtained. Also reported is a tentative mechanism which copes with the results obtained.