Effect of polymer stereoregularity on polystyrene/single-walled carbon nanotube interactions

Abstract

We use a combination of computational and experimental studies to elucidate the effect of polymer stereoregularity on the capability of polystyrene interacting with single-walled carbon nanotube (SWNT) surfaces. Calculated binding energies on complexes of lightly oxidized SWNT with isotactic and atactic polystyrene favor the former, which suggests that the isotactic polymer interacts more effectively with the SWNT. The glass transition temperature (T g ) of the isotactic polystyrene/SWNT matrix increases from 90.9 to 100.5 o C as the SWNT content is increased to 0.5%, whereas the glass transition temperature of the atactic polystyrene/SWNT matrix is invariant with increasing SWNT content. Rotating frame 13 C T 1ρ relaxation rates for the isotactic polymer/SWNT matrix increases from 2.15 to 2.43 ms as SWNT is increased from 0.25 to 1.0 %. However, the rotating frame 13 C T 1ρ relaxation rates for the atactic polymer/SWNT matrix decreases from 2.50 to 1.60 ms as SWNT is increased from 0.25 to 1.0 %. Our results demonstrate that the SWNT is better dispersed within the isotactic polystyrene and the better dispersion is associated with more effective interaction of isotactic polymer with the SWNT surface.

The Microbial Production of Polyhydroxyalkanoates from Waste Polystyrene Fragments Attained Using Oxidative Degradation

“…The 13 C-NMR spectra (see Figure 5) show the carbon sources (PS0–4) are atactic polystyrene; this is clearly visible from inspection of both the methine (Figure 5b) and ipso (Figure 5c) carbon regions of the spectrum. Assignments of the carbon signals are displayed on the spectra and are in agreement with the assignments of London et al [45] for the ipso region and Cheng and Lee [46] for the methylene region. The effect of thermo-oxidative degradation on the polymeric microstructure of the degraded samples (PS1–4) appears to be minor, with no major differences observable in either the proton or 13 C spectra from that of PS0.…”

Functionalized Carbon Nanotubes with Phosphorus- and Nitrogen-Containing Agents: Effective Reinforcer for Thermal, Mechanical, and Flame-Retardant Properties of Polystyrene Nanocomposites

“…It shows that the PS macromolecular chains probably wrap the DPPA-MWCNT nanoparticles resulting in the non-covalent crosslinking. [1][2][3][4][5] The good dispersion is attributed to two reasons. The good dispersion is attributed to two reasons.…”

Comparative Studies on Thermal, Mechanical, and Flame Retardant Properties of PBT Nanocomposites via Different Oxidation State Phosphorus-Containing Agents Modified Amino-CNTs

“…On the contrary, DPP(O)-A-CNT and DPP(O 3 )-A-CNT nanoparticles are well integrated with the PBT molecular chains, leading to the absence of the interface between functionalized CNTs and PBT. The PBT macromolecular chains probably would have enveloped the DPP(O)-A-CNT and DPP(O 3 )-A-CNT nanoparticles, resulting in the formation of non-covalent crosslinking points [ 27 , 28 , 29 ].…”

“…On the other hand, the T c value of the three nanocomposites increases with the increasing quantity of oxygen atom, due to the different hydrogen-bond interaction: (PBT/DPP(O 3 )-A-CNT > PBT/DPP(O)-A-CNT > PBT/DPP-A-CNT). The strong hydrogen-bond interaction promotes the PBT macromolecular chains to envelope the CNT nanoparticles thereby resulting in the formation of non-covalent crosslinking points, which can strongly restrict the segmental motion of PBT chains [ 27 , 28 , 29 ], thus accelerating its crystallization process. When the crystallization begins at higher temperature, more perfect and stable crystals will be formed, which is beneficial to the improvement of mechanical strength as well as the reduction of multiple melt behavior.…”