A model of hydrolysis of aliphatic polyesters in biological media under diffusive limitation of water

Commonly used models relied on the assumption of water excess and pseudo first order of hydrolysis of polymer molecules. In fact, the variety of model parameters allows describing of experimental data rather well in spite of wrong initial concepts.

The system of differential equations which take into account water diffusion, second order hydrolysis reaction, autocatalytic hydrolysis channel and diffusion of low molecular weight (short) oligomers is proposed and numerically solved. We demonstrated interplay of degradation type (“V” to “S”) just varying the water diffusion coefficient. The main advance of this work comprises the ability to compare different scenarios of polymer degradation with respect to kinetics of water diffusion and water reactions with polymer molecules.
This work was supported by Russian Foundation for Basic Research (grant No. 16-29-07356) in part of experimental work and by the Ministry of Science and Higher Education within the State assignment FSRC «Crystallography and Photonics» RAS in part of mathematical model development.

Results were obtained using Wolfram Mathematica