**4. Conclusions**

Crazing was successfully developed in the PLA/PAni film to improve the biodegradability of the polymer film. The presence of crazes in the PLA/PAni film was confirmed by optical microscope and SEM. Crazes in the PLA/PAni film did not show significant tensile strength changes but showed progressive increases in tensile strain by 150% and decreases in Young's modulus. The non-crazed PLA/PAni film showed Young's modulus of 1113 MPa, while the crazed PLA/PAni film showed Young's modulus of 651 MPa. The differences that occurred in tensile strain and Young's modulus were due to the increment in chain mobility and decrement in chain entanglement of the polymer film. Meanwhile, the crazed PLA/PAni film improved the biodegradability of the polymer film. The significant weight loss of the crazed PLA/PAni film was observed after 21 days of biodegradation as 42%. This was due to the loss of crystalline nature of the polymer film in the presence of crazes, which induced the erosion degradation of enzymes. Thus, the appearance of crazes in the PLA/PAni film enhanced the biodegradability of the polymer film. The polymer film with high biodegradability based on PLA and PAni was formulated and this study could be useful in a packaging application to lower the polymeric pollution to the environment. **Author Contributions:** Conceptualization, S.-W.P. and A.B.; Formal analysis, P.-Y.W., S.-W.P., A.T., S.T. and A.B.; Funding acquisition, A.B.; Investigation, P.-Y.W., S.-W.P., A.T., S.T and A.B.; Methodology, P.-Y.W., S.-W.P., A.T., S.T. and A.B.; Resources, A.T. and S.T.; Supervision, S.-W.P. and A.B.; Validation, P.-Y.W., S.-W.P. and A.B.; Visualization, P.-Y.W. and A.B.; Writing—original draft, P.-Y.W.; Writing review & editing, S.-W.P., A.T., S.T. and A.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** Research University Grant: GUP-2020-041 and Japan Student Services Organization: 2019.

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

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** The authors would like to acknowledge the Department of Chemistry, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM) and GUP-2020-041 grant for the funding support in this study. This work was performed, in part, at Gifu University (Japan). The scholarship support from Japan Student Services Organization (JASSO),2019 is gratefully acknowledged.

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