Surface Modification of Polyester Fiber With Sericin for Cold Reactive Dyeing

Polyester is a synthetic fiber which is widely used in textile industry because it has a superior properties such as a good tangle resistance and good resistance to high temperatures. So far, polyester can only be dyed by hydrophobic dyes. Research show that polyester can be dyed with cold reactive dyes which is a hydrophilic dyes. This is done by modifying the surface of the fabric through a coating with sericin. Sericin can be obtained from liquid waste of silkworm cocoons degumming. As a hydrophilic protein, it is composed of 18 types of amino acids that mostly serine and aspartic acid. Sericin is attached to the polyester fiber surface by trapping using a melamine formaldehyde polymer network. The amino acids of sericin will bind the reactive dyes with ionic bonds, so polyester fabrics looks dyed. The aim of this research is to observe the optimum concentration of sericin by varying of sericin on 0, 10, 20 and 30 g/L. Trapping of sericin to polyester fabrics with a melamine formaldehyde shows that FTIR absorption peak in the range of wave number at 1556.55 cm-1 and 1651 cm-1, indicated that sericin has been attached to the surface of the polyester fabric surface. Other than that, SEM test showed that there is morphological surface differences between the untreated polyester and the polyester coated by sericin. Variations of sericin concentration affect to the depth color (K/S value). Utilizing sericin as addition which is trapped by melamin formaldehidresin will make polyester can be dyed by cold reactive dyes. This indicates that the polyester fiber surface modification has been performed so as to change the dyeing properties.