**4. Conclusions**

In this study, PLCL and PLDLA, which are representative, implantable polymer materials, were selected as target material models to conduct a predictive simulation study on the radiation damage and prediction of biodegradable polymer materials.

A decomposition evaluation using gamma rays was performed through the characterization (ATR-FTIR, GPC, and DSC thermal analysis) of PLCL and PLDLA films according to the irradiation dose. No clear structural decomposition was observed in the ATR-FTIR results, but changes in the melting point ( *T* m) and average molecular weight ( *M*n and *M* w) of the PLCL film decreased as the irradiation dose increased, as shown by the DSC and GPC analysis results. Similarly, in the PLDLA film, no clear structural decomposition was observed in the ATR-FTIR results. Yet, in the GPC analysis results, a decrease in the average molecular weight ( *M*n and *M* w) of the PLDLA film was observed as the irradiation dose increased. In contrast, a change in the glass transition temperature ( *T*g) was observed at irradiation doses greater than 100 kGy, and it seemed that the optimal sterilization dose to maintain thermal stability could be derived.

In addition, PLCL and PLDLA films were selected as damage analysis and prediction models and were manufactured in the form of films; a Geant4 simulation was performed using gamma rays. Consequently, a number average molecular weight ( *M*n) change curve similar to the actual measurement result was confirmed. This study is a preliminary study for the analysis and prediction of radiation damage of biodegradable polymer materials using gamma rays, which could be possible.

**Author Contributions:** Conceptualization, H.-E.S. and H.-J.G.; methodology, H.-E.S. and Y.-H.Y.; software, Y.-H.Y. and J.-H.P.; validation, D.-H.L. and Y.-R.N.; formal analysis, H.-E.S.; investigation, Y.-R.N.; data curation, J.-H.P. and N.-H.L.; writing—original draft preparation, H.-E.S. and Y.-H.Y.; writing—review and editing, H.-J.G.; supervision, N.-H.L.; project administration, H.-J.G. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by the Nuclear R&D program of the Ministry of Science and ICT.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.
