Stress-strain behaviour of graft copolymers of methyl methacrylate and natural wool fibres

The graft polymerization of methyl methacrylate onto wool, using LiBrK₂S₂O₈ and Na₂S₂O₃H₂O₂ redox systems as initiators, does not change dramatically the stress-strain behaviour of single fibres even for high graft yields. Variations in tensile properties are essentially due to an important radial swelling effect of the deposited polymer accompanied by a moderate increase of internal viscosity and, in the case of Na₂S₂O₃H₂O₂ initiation, to interference from oxidative processes.