Strong process-structure interaction in stoveable poly(urethane-urea) aligned carbon nanotube nanocomposites

Aligned carbon nanotube morphogenesis predicts physical properties of their polymer nanocomposites

“…52 This is a critical and useful assumption in this work as many polymers, particularly thermoplastics, have strong process-nanostructure interactions causing the polymer morphology and crystallization degree to alter, among other effects. [53][54][55] Statistically representative 3D reconstructions of A-CNTs in the A-PNCs of ex situ V f s of 1.00%, 5.00%, 6.00% and 11.70%, estimated from the change in volume of the forests before epoxy infiltration, were obtained using electron tomography as described earlier ( Fig. S1a-d †).…”

Effects of modified carbon nanotubes with different sizes on properties of epoxy shape memory polymers

“…Therefore, as MWCNTs content adding, it gets harder to recover to its original state, more energy and time would be needed for all shape recovery process when temperature above T g . Once MWCNTs content above 0.5%, on one hand, the introduction of MWCNTs can improve the heat transfer performance of composites 29, 34 ; on the other hand, the increase of MWCNTs filler would lead to agglomeration that weakens the entanglement between MWCNTs with polymer chains. Thus polymer chains movement of composites with 1% MWCNTs become rapid, resulting in an increase of shape recovery speed and ratio.…”

Ultrahigh Carbon Nanotube Volume Fraction Effects on Micromechanical Quasi-Static & Dynamic Properties of Poly(Urethane-Urea) Filled Nanocomposites

“…Poly(urethane-urea) (PUU) prepolymer was synthesized using a blocked-isocyanate, diamine, and polyol identical to the method outlined previously [18]. The mixed and degassed prepolymer was poured onto the densified CNT forests and heated at atmospheric pressure to 130 °C for 24 h per the previously prescribed cure cycle [18]. Two stoichiometric variations of PUU were used in the present study: PUU211 and PUU541, where the naming denotes HDMI:DETA:PTMO ratios.…”

“…The densified forests were placed into silicone molds to confine the samples and prevent expansion during polymer infusion. Poly(urethane-urea) (PUU) prepolymer was synthesized using a blocked-isocyanate, diamine, and polyol identical to the method outlined previously [18]. The mixed and degassed prepolymer was poured onto the densified CNT forests and heated at atmospheric pressure to 130 °C for 24 h per the previously prescribed cure cycle [18].…”

“…Moderate interactions have been observed previously with this material in the presence of aligned CNTs [17,18], and so a deeper dive into understanding the nature of this interaction and the mechanical implications is necessary. Quasi-static and dynamic nanoindentation results will be presented here.…”