Application of the Arrhenius Equation to Rat Tail Tendon Collagen

Abstract

AN important and widely investigated property of collagen is its hydrothermal shrinkage. The concept of shrinkage temperature (T_s) has been developed as a manner of characterization of the hydrothermal stability of the fibre. Shrinkage temperature is determined by heating the fibre in water, the temperature of which is increased at the rate of 2 deg./min. The fibre is kept under observation, and the temperature at which contraction occurs is noted as the T_s of the fibre in question. Usually a range of temperature is recorded because the end point of reaction is not precise. Although useful, the concept of T_s is not a strictly valid one. Shrinkage curves constructed from data on length of fibres plotted against time at various temperatures clearly establish that the process of shrinkage of collagen is a rate phenomenon and that a true shrinkage temperature does not exist from a thermodynamic point of view. For this reason, Weir and Carter^1,2 examined the hydrothermal stability of collagen as a rate process. They stated that the reaction appeared to be of the first order and applied the theory of absolute reaction rates to the process. The half-time of the fibre shrinkage was taken as an index of the reaction rate at each of several temperatures and these t_1/2 values were substituted for rate constants in the Arrhenius equation.