Effect of crosslinking agents (basic chromium sulfate and formaldehyde) onthe thermal and thermomechanical stability of rat tail tendon collagen fibre

The role of covalent and coordinate covalent crosslinks on the thermal and mechanical properties of rat tail tendon (RTT) collagen fibre has been stud ied. The tendons were tanned with formaldehyde (HCHO) and basic chromium su lfate (BCS). Thermal properties of the crosslinked fibres were studied usin g shrinkage temperature, hydrothermal isometric tension behaviour and diffe rential scanning calorimetry (DSC). Mechanical properties were analysed usi ng tensile strength and stress relaxation behaviour. The results show that BCS tanned RTT exhibits a marked increase in the peak temperature and entha lpy changes when compared to both native and HCHO tanned RTT. This may be d ue to a net increase in the number of intermolecular crosslinks arising fro m both electrovalent and coordinate covalent interactions during BCS tannin g. After treatment with urea there is a decrease in the peak temperature an d the enthalpy changes of BCS tanned RTT fibres suggesting alterations in t he secondary structure of collagen are possible even after tanning. An incr eased long range order is seen in the case of chromium tanned fibres in com parison to HCHO treated analogue. (C) 2000 Elsevier Science B.V. All rights resented.