Structural orientation and tensile behavior in the extrusion-stretched sheets of polypropylene/multi-walled carbon nanotubes' composite

Structural, mechanical and thermal studies of double‐molded isotactic polypropylene nanocomposites with multiwalled carbon nanotubes

“…Therefore lamellar and crystalline orientation is analyzed to be nearly the same structure as that observed in MWCNTs have often been reported to have an orienting effect on the polymer matrix. 26,27 In this study, however, no significant difference in orientation is found between iPP and the composites. This lack of strong orientating effect is in agreement with published report.…”

Structure and tensile properties of polypropylene/carbon nanotubes composites prepared by melt extrusion

“…Pristine PP shows a regular spherulite size of 220 -160 µm. Decrease in spherulite size with increasing of CNTs content in PP nanocomposites has been observed earlier and can be attributed to the increased number of nucleation centers [8,[16][17][18]. At the equivalent CNTs concentration, bigger spherulitic sizes were observed for PP/CNTs1 nanocomposites compared to that obtained after adding PP-g-MAH nanocomposites, which implies good dispersion of CNTs in the nanocomposites after adding MAH-g-PP.…”

Reinforcing polyamide 1212 with graphene oxide via a two-step melt compounding process

“…10b), aligned GO nanosheets were exfoliated efficiently and it indicated that the interfacial interaction existed between GO nanosheets and PA1212 matrix. Meanwhile, according to literature reports, when the composites were stretched, the interfacial interaction between polymer matrix and nanofillers was enhanced due to the strain induced crystallization, such as the formation of the special crystal structures and the interphase [24,[26][27]40]. The crystallization properties and morphology of the composites were investigated to further elucidate the composite reinforcing effect as follows.…”

“…Studies have shown that special crystalline structures, such as hybrid shish-kebab, cylindrical crystal, and microfibrils, are composed of rigid nanofillers as nuclei form in a polymer matrix under strain and temperature field [24,25,46]. These oriented special crystalline structures are beneficial in composite reinforcement [26,27]. In addition, given the heterogeneous nucleation effect of the aligned GO, the reinforcing effect must have originated from the oriented crystalline structures because of the rigid nanosheets that functioned as nuclei to reinforce the entire oriented crystals.…”

“…Nanofillers exhibit heterogeneous nucleation effect in a polymer matrix [22,23]. Polymer chains epitaxially crystallize on nanofiller surfaces [24,25], and polymer chain relaxation is hindered [26,27]. Therefore, the alignment effect of GO nanosheets on the composites' mechanical properties is of particular interest.…”