Ball-milled CNTs

Ball-milled CNTs Figure 6.14 SEM image of ball-milled CNTs. 

Figure 21.8 TEM images of raw CNTs and ball-milled CNTs.

It can be found that after the ball-milling treatment, the CNTs were loose in bulk, which was beneficial to the dispersion and penetration of CNTs inside the rubber macromolecular chains. Furthermore, there was no drastic decrease in the aspect ratio of the CNTs due to the short milling time (0.5 h), which can... 

Therefore, the key step for the in-situ polymerization of PUCNs is the dispersion of CNTs in macromolecular polyols. In order to reduce the aggregations, it is necessary to physically or chemically modify the surface of CNTs to reduce the van der Waals force among the nanotubes. Strong mechanical tools such as ball milling and ultrasonic treatment can be used to help break down the aggregation of CNTs. The kinetics of PU chain growth should be taken into account although it is rarely reported in up-to-date publicahons. 

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