Estimation of the Mechanical Properties of Poly(3-hydroxybutyrate) from IR Data

Abstract Despite the sustainability, biodegradability, and biocompatibility of microbial polyesters, as well as their potential to replace polyolefins, the market share of these biopolymers is still marginal. The primary factors that impede the success of microbial polyesters are related to their poor thermal stability and the degradation during processing that negatively affects the mechanical performance of the final product. Due to the complexity of the mechanism of degradation and the vast number of factors that influence the mechanism, the outcome of the degradation cannot be predicted with high confidence. Our present work addresses both difficulties. First, the thermal stability of poly(3-hydroxybutyrate) was successfully improved by a stabilizer system based on pomegranate extract. Second, we have developed a computational method that can be used for the estimation of the mechanical properties of processed microbial polyesters from IR data. The computational method is based on an unprecedented hybrid model that incorporates both linear and nonlinear components. The linear component is based on multivariate data analysis and quantizes the correlation between IR data and the extent of degradation. In contrast, the second component consists of a power function in order to be able to describe the nonlinear correlation between the extent of degradation and the mechanical properties. By using the hybrid model, indicators of mechanical performance, such as tensile strength, can be estimated from IR data, which was not achieved before.