Computer simulation of stereochemical structure of biodegradable poly(d,l-lactide-co-l-lactide)

A computer simulation method based on the Monte Carlo technique is suggested to investigate the stereochemical structure of poly(d,l-lactide-co-l-lactide) (PDLLA). The Monte Carlo model is set up according to the reactivity probabilities of two kinds of isomer RR and SS during ring-opening chain propagation. The simulation results for Tetrads and Hexads intensities are in good agreement with experimental results for 13C NMR. Some other important parameters for the stereochemical structure of PDLLA are also obtained from the computer simulation, such as the proportion of units of each isomer on the polymer chain, the sequence length distribution and the Run numbers. The influence of reactivity ratio r and feed ratio p on the stereochemical structure is analyzed and discussed in detail. This computer simulation method has proved to be a convenient method for establishing structure–properties relationships of certain polymers whose stereoregularity can be adjusted, such as PDLLA.