Rheological Behavior of Amino-Functionalized Multi-Walled Carbon Nanotube/Polyacrylonitrile Concentrated Solutions and Crystal Structure of Composite Fibers

Abstract

Abstract:The rheological behavior of amino-functionalized multi-walled carbon nanotubes (amino-CNTs)/polyacrylonitrile (PAN) concentrated solutions in the dimethyl sulphoxide solvent and the effects of the amino-CNTs on the PAN precursor fibers by wet-spinning method were investigated. The amino-CNT/PAN concentrated solutions prepared by in situ solution polymerization with homogeneous dispersion of amino-CNTs have higher complex viscosity, storage modulus and loss modulus as compared to the control PAN concentrated solutions containing 22% PAN polymer by mass. The composite fibers with amino-CNTs of 1 wt % have lower degree of crystallization, crystal size and crystal region orientation compared to the control PAN precursor fibers. However, the amino-CNT/PAN composite fibers with diameter of about 10.5 µm exhibit higher mechanical properties than the control PAN precursor fibers with diameter of about 8.0 µm. Differential scanning calorimetry analysis demonstrated that the cyclization reaction in composite fibers have broad exothermic temperature range and low exothermic rate. These results indicate that the addition of amino-CNTs into PAN precursor fibers is beneficial to controlling the process of thermal stabilization and obtaining the higher performance of composite fibers.

The Structure and Properties of Polyacrylonitrile Nascent Composite Fibers with Grafted Multi Walled Carbon Nanotubes Prepared by Wet Spinning Method

“…Moreover, at the same wet spinning conditions, the average diameter of the grafted MWCNT/PAN nascent composite fibers was about 44 μm, which is larger than that of the PAN nascent fibers with a diameter of about 41 μm. These may be ascribed to the effects of the grafted MWCNT on the rheological properties of spinning solutions [33], and indicated that network structures were formed between the grafted MWCNTs and the PAN polymer during polymerization. These results are beneficial for improving the mechanical properties of the nascent composite fibers, which can be proved in Table 3.…”

A Cyclized Polyacrylonitrile Anode for Alkali Metal Ion Batteries

“…High-resolution transmission electron microscopy (HRTEM) image of cPA N showed an amorphous structure with some parallel regions (Figure 1b)w hich are ascribed to the p-p stacking of the ladder structures in cPA N. Thedefect-rich structure of cPA N shown in HRTEM image (Figure 1c)indicates the low degree of cross-linking between ladder structures.T he cyclization reaction of PA Ncompleted as revealed by Fourier-transform infrared (FTIR) spectroscopy.P AN showed atypical peak at 2245 cm À1 (Figure S3), which is ascribed to the characteristic nitrile group (C N). [36] After cyclization,this peak completely disappeared. Instead, ap eak at 1596 cm À1 (Figure 1d)a ppeared, indicating the formation of C=No rC =Cb onds in cPA N. Thep eak at 1257 cm À1 reflects the existence of CÀN single bonds in cPA N. Thep eak at 1376 cm À1 is due to the bending of CÀHb onds on the backbone of cPA N. Minor methylene group (CH 2 )e xisted due to the hydrogen radical reactions.…”

Thermal Analysis and Crystal Structure of Poly(Acrylonitrile-Co-Itaconic Acid) Copolymers Synthesized in Water

“…The peaks at around 2939 cm −1 and 1453 cm −1 are assigned to the stretching vibration and the bending vibration of -CH2 groups, respectively [42]. The weak peak at about 1625 cm −1 is attributed to the hydrolysis of AN units during polymerization [43]. The peaks at around 1360 cm −1 and 1074 cm −1 are attributed to the symmetric bending vibration of -CH3 groups and the bending vibration of -CN groups.…”