Ultrasonically assisted compounding of CNT with polypropylenes of different molecular weights

作者：Zhong Jing; Isayev Avraam I^*

来源：Polymer, 2016, 107: 130-146.

DOI：10.1016/j.polymer.2016.11.006

• Ultrasound
• Polypropylene
• Carbon nanotubes
• Twin-screw extruder

Carbon nanotubes (CNTs) were compounded with four polypropylenes (PPs) of different molecular weights and viscosities without and with ultrasonically assisted twin-screw extrusion. The dispersion of CNT and the effect of viscosity on ultrasonically induced polymer degradation at different amplitudes were studied. Three preparation methods, differing in the sequence of ultrasonic treatment application, were applied to prepare PP/CNT composites and investigate the bubble cavitation mechanism inside and outside of CNT agglomerates in composites. In Method 1, the ultrasonic treatment was applied in the masterbatch dilution step, while in Method 2 it was applied in the masterbatch preparation step. In Method 3, direct ultrasonic compounding method was applied. Ultrasonic power consumption, small amplitude oscillatory shear (SAOS), creep and recovery, electrical conductivity were measured and morphological analysis was carried out to evaluate the dispersion of CNT in PP. The ultrasonic treatment was found to have the most prominent effect on improving the dispersion of CNT using Method 2. The ultrasonic treatment using Method 3 was more efficient than that using Method 1. Moreover, it was found that ultrasonic treatment had more notable effect on improving the dispersion of CNT in the higher viscosity PP matrix. The theological and electrical percolation threshold was significantly reduced with ultrasonic treatment in higher viscosity PP/CNT composites. The bubble cavitation mechanism inside of CNT agglomerates was found to be dominant in breakage of the agglomerates during the ultrasonic treatment.

• 出版日期2016-12-19