Two phenomena are then in competition when increasing the NR content, the reduction of contact area between the two
polymers and the increase of nucleation density.
In our case, it appears that the reduction of contact area is the predominant effect, since there was formation of a
continuous “net-like” structure of NR.
Another factor to be taken into account is that the increased NR concentration also restricted the mobility of the PLA chains during crystallization, resulting in reduced crystallinity of PLA in the blend.
Obviously, the crystallinity of PLA in our study is not the reason for the significant improvement of toughness
since the crystallinity of PLA is small in D65/35.