Unique Morphology of Polylactide/Poly(ε-Caprolactone) Blends Extruded by Eccentric Rotor Extruder

作者：Li, Jiqian; He, Hezhi^*; Zhu, Zhiwen; Xu, Mohong; Gao, Junfei; Gu, Qun; Tan, Bin^*

来源：JOURNAL OF POLYMERS AND THE ENVIRONMENT, 2022, 30(10): 4252-4262.

DOI：10.1007/s10924-022-02503-4

• Polylactide
• Poly(epsilon-caprolactone)
• Extensional flow
• Shear flow
• Immiscible blends

In this work, PLA/PCL blends were extruded by either eccentric rotor extruder (ERE) based on extensional flow or twin-screw extruder (TSE) based on shear flow. The morphologies of PLA/PCL blends were investigated. The results showed that PLA/PCL blends showed co-continuous structure with PCL content varying from 20 to 50 wt% when the blends were extruded by ERE, while only 50 wt% PCL blends showed co-continuous structure when extruded by TSE. Furthermore, ERE provided better mixing properties, i.e., better dispersion of minor phase with smaller droplet sizes, promoting the formation of co-continuous structures with lower amounts of minor component. ERE also provided less polymer chain scission than TSE, implying better comprehensive properties of extruded polymers. DSC curves of PLA/PCL blends showed that the cold crystallization temperature (T-cc) of PLA shifted to lower temperature and the crystallinities of PLA increased when the blends were extruded by ERE. Implication of this work is that extensional flow is a more powerful method than shear flow in processing immiscible blends, which has high potential for compounding biobased and biodegradable polymer blends for enhanced properties.

• 单位
  中国科学院; 福建工程学院