Synthesis, characterization and properties of carboxymethyl kappa carrageenan

► Carboxymethyl κ-carrageenan (CMKC) was synthesized by κ-carrageenan and ClCH2COOH. ► CMKC was characterized by 13C NMR, degree of substitution and molecular weight. ► The introduction of -CH2COO− conferred antibacterial activity onto κ-carrageenan. ► The product also exhibited good anticoagulant activity and moisture absorbability. ► CMKC would be an excellent wound healing material and substitute for heparin.