An entropy spring model for the Young’s modulus change of biodegradable polymers during biodegradation

Modelling the degradation and elastic properties of poly(lactic-co-glycolic acid) films and regular open-cell tissue engineering scaffolds

“…This section is organised as follows: an overview of the phenomenological degradation model of Wang et al (2010), which predicts the changes in the molecular weight distribution during degradation, is presented (hereafter referred to as the molecular weight model); the entropy spring model which relates Young's modulus to the molecular weight distribution is described (hereafter referred to as the mechanical properties model); the coupling of these two models is then described; and finally we outline the simulations performed in the current study. An overview of each model and the coupling scheme is shown in Figure 1.…”

“…A number of models have been presented to predict the mechanical properties of degradable polymers (Hayman et al, 2014;Soares et al, 2010;Vieira et al, 2014;Vieira et al, 2011;Wang et al, 2010). A model was developed by Vieira et al (2014) based on the relationship between fracture strength and molecular weight for thermoplastic polymers to predict the mechanical properties of PLA-PCL fibers during degradation.…”

“…Wang et al (2010) proposed a model for amorphous biodegradable polymers, based on the relationship between the Young's modulus and the number of polymer chains. This model is physically motivated by the hydrolytic random scission of the polymer chains.…”

“…Motivated by recent developments, an integrated modelling framework based on the work of Wang et al (2010; was developed in the current study to predict the degradation of biodegradable polymers and, in particular, PLGA. The first objective of this study was to develop a computational framework that links both of the key physical processes: the reduction in molecular weight over time during degradation; and the relationship between Young's modulus and molecular weight (and polymer chain length).…”

An atomic finite element model for biodegradable polymers. Part 2. A model for change in Young’s modulus due to polymer chain scission

“…Wang etc al. (Wang et al, 2010) considered the entropy spring model for rubbery amorphous polymer and considers short polymer chains to have negligible effect on the entropy change in a linear biodegradable polymer during its deformation. The model was demonstrated to be able to fit experimental data for Young's modulus degradation.…”