Electron Beam-Induced Compatibilization of PLA/PBAT Blends in Presence of Epoxidized Soybean Oil

Blending of polymers can enhance performance of plastics and can give the opportunity to broaden the application fields. Especially the brittleness of poly(lactic acid) (PLA) is an issue, that is often addressed by blending it with soft polymers like poly(butylene adipate terephthalate) (PBAT). The immiscibility of those two polymers leads to limited properties of the blend. This study aimed to examine the application of electron-beam treatment with the implementation of a compatibilizing agent. PLA and PBAT were compounded with the addition of epoxidized soybean oil (ESBO) in different ratios and extruded into flat films. These were treated with electron beams at irradiation doses ranging from 12.5 to 100 kGy. The films thus produced were characterized by differential scanning calorimetry, size exclusion chromatography, scanning electron microscopy and tensile testing. A significant change in the glass transition temperatures of the blend partners was observed, as well as a substantial increase in elongation at break, even in PLA-rich compositions. These findings indicate improved compatibilization. Furthermore, the use of epoxidized soybean oil showed a changed extraction behavior of PBAT, indicating a formed binding to PLA. The results show that electron-beam treatment can significantly improve the compatibility between different polymers in blends, leading to enhanced mechanical and thermal properties.

Automated summary

Blending of polymers can improve the performance of plastics and expand their application fields. By blending poly(lactic acid) (PLA) with poly(butylene adipate terephthalate) (PBAT), the brittleness of PLA can be addressed. However, the immiscibility of these two polymers limits the properties of the blend. This study explored the use of electron-beam treatment with a compatibilizing agent to improve compatibility and found significant enhancements in mechanical and thermal properties.