Dyeing performances of ramie fabrics modified with an amino-terminated aliphatic hyperbranched polymer

摘要

An amino-terminated aliphatic hyperbranched polymer (HBP-NH2) was used to modify ramie fabric. The molecular weight of HBP-NH2 was established by GPC. HBP-NH2 structure might represent as BA(4)BA(3)BA(3) (third generation). The total amine value, secondary amine value and primary amine value of HBP-NH2 were 291.59, 210.14 and 81.45 mg/g respectively with hydrochloric acid-ethanol titration method. The unmodified and modified ramie fabrics were characterized by XRD and FE-SEM. XRD results showed a transformation of crystalline structure from ramie cellulose I to cellulose II allomorph during mercerization and epichlorohydrin modification, and the crystalline structure of cellulose II maintained with obvious crystallinity index increase after HBP-NH2 modification. Nitrogen content of HBP-NH2 modified fabrics were 1.25-2.61 %. Cationization degree (D-C) of HBP-NH2 modified ramie fabrics were 4.41-9.40 %. C.I. Reactive Red 2 was applied to study the dyeing performance of modified fabrics. The modification parameters were optimized as 50 A degrees C for 5 h when the concentration of HBP-NH2 was 8 g/L. K/S value and dye uptake of modified fabric was 23.64 and 85.6 % respectively under optimal modification conditions. The washing, rubbing and light fastness of modified ramie fabrics were acceptable. The tensile strength and tear strength of HBP-NH2 modified ramie fabrics were lower than those of unmodified fabrics. The warp, weft of tensile and tear strength retention of modified fabrics were between 85.23 and 87.50 %. The HBP-NH2 modification mechanism and dyeing mechanism on ramie fabric were suggested.