A low seepage threshold and super-toughness of polybutylene succinate-based composites with double percolation structure: Synergy of multi-wall carbon nanotubes and polyvinyl butyral

作者：Jia, Shikui^*; Zhang, Xiangyang; Zhu, Yan; Yan, Zongying; Zhang, Guizhen; Zhao, Zhongguo; Ding, Liu

来源：Polymers for Advanced Technologies, 2022, 33(9): 2760-2773.

DOI：10.1002/pat.5730

• double percolation structure
• polybutylene succinate
• polyvinyl butyral
• seepage threshold
• super-toughness

To obtain a super-toughness and low seepage threshold for the conductivity of biodegradable soft polymer material, biodegradable polybutylene succinate (PBS)-based composites with different contents of polyvinyl butyral (PVB) and multi-wall carbon nanotubes (MWCNTs) were prepared by melt-blending method. Synergy effects of different modified MWCNTs and PVB on the morphology, crystallization, and electrical and mechanical properties of MWCNTs/PVB/PBS composites were examined by Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscopy (TEM), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), polarizing microscope (POM), resistance tester, and universal testing machine. Compared with pure PBS, with increasing MWCNT content, the electrical conductivity of the MWCNTs/PBS composites showed an upward trend, and the percolation threshold for electrical conductivity of the MWCNTs/PBS composites reached 0.47%. The electrical conductivity of the PBS composite mixed with 1.0 wt% of surface modified MWCNTs slightly increased by one order of magnitude compared with that of pure PBS. By adding 20 wt% of the PVB and 1 wt% of the unmodified MWCNTs, the electrical conductivity of the MWCNTs/PVB/PBS composite increased by seven orders of magnitude compared with that of pure PBS. The percolation threshold for electrical conductivity of the MWCNTs/PVB/PBS composites decreased to 0.049% owing to the formation of double percolation structure. Furthermore, compared with pure PBS, when the PVB content was 20 wt%, and the MWCNTs was 1 wt%, the elongation at break and V-notch impact strength of PBS-based composite dramatically increased by approximately 300% and 12-fold, respectively.