Viscoelastic analysis of the keratin composite. II. Thermal and hygral expansion

An analogy with the theory of uncoupled elasticity is used to formulate the thermal/hygral viscoelasticity of the keratin composite. The anisotropic moisture swelling and thermal expansion are expressed in terms of the mechanical and thermal/hygral properties of the constituent phases and filament volume fraction. The theoretical moisture swelling/hygral expansion of the matrix phase in the keratin fibre increases non-linearly with fibre regain. The filament or microfibril phase changes in dimension only slightly as compared to the matrix phase. The volumetric thermal expansion coefficient for wet keratin is in good agreement with the value determined for wet wool. For part I see abstract 1989/2410.