Improved electrical conductivity of TPU/carbon black composites by addition of COPA and selective localization of carbon black at the interface of sea-island structured polymer blends

Abstract

The electrical percolation threshold of carbon black (CB) in thermoplastic polyurethane (TPU) decreases by 46% with the incorporation of 20 wt% polyamide copolymer (COPA) through selective localization of CB particles at the interface of sea-island structured TPU/COPA blends. Composites with a composition of TPU/20 wt% COPA/9 wt% CB were prepared by four different mixing sequences and their morphologies were investigated by FESEM and TEM. The majority of CB particles were observed at the interface of sea-island structured blends irrespective of the compounding sequence used, although the percentage of CB particles at the interface is considerably less in the composite prepared by adding COPA to premixed TPU/CB. The driving force for the interfacial localization of most CB particles is the hydrogen bonding of CB with both TPU and COPA, which is confirmed by FTIR and DMA investigations. CB particles act like Janus particle-type compatibilizers with bonded TPU molecules toward the TPU phase and bonded COPA chains toward the COPA phase. Highly efficient conductive paths are formed through the CB-covered domains and a short inter-domain distance.

Highly efficient electrically conductive networks in carbon‐black‐filled ternary blends through the formation of thermodynamically induced self‐assembled hierarchical structures

“…Another important thermodynamic reason to support this prediction is hydrogen bonding of CB with both TPU and PA6. The hydroxyl, carbonyl, and carboxyl groups of CB particles could form hydrogen bonds with either the urethane and ester groups of TPU or the amide groups of PA6 during compounding; this was similar to the case of TPU–COPA–CB composites . However, the probability of CB forming hydrogen bonds with POM was much lower than the those of it forming hydrogen bonds with TPU and PA6 because of a lack of carbonyl groups in the POM chains.…”

“…Recently, our research group found that φ c in TPU can be dramatically reduced through the addition of a suitable second polymer (polyamide) and the selective localization of most CB particles at the interface of sea‐island structured polymer blends . The structure of interfacial localization of CB particles is stable because CB particles hydrogen‐bonded with both TPU and polyamide can act like Janus‐particle‐type compatibilizers.…”

Enhanced Solid Particle Erosion Properties of Thermoplastic Polyurethane‐Carbon Nanotube Nanocomposites

“…It is well known that the groups on CNTs (O–H peak at 1630 and 3400 cm −1 in Figure a) can form hydrogen bonds with functional groups on the TPU chains. Although the van der Waals interaction between CNTs could cause the entanglement, the hydrogen bonds between CNTs and TPU chains could strengthen the mechanical properties of nanocomposites . In this work, we introduced the hydrogen bonding index (R: ratio of two peaks at 1700 and 1730 cm −1 ) to illustrate the change of hydrogen bonds between CNTs and TPU chains .…”

“…Although the van der Waals interaction between CNTs could cause the entanglement, the hydrogen bonds between CNTs and TPU chains could strengthen the mechanical properties of nanocomposites. [68,69] In this work, we introduced the hydrogen bonding index (R: ratio of two peaks at 1700 and 1730 cm −1 ) to illustrate the change of hydrogen bonds between CNTs and TPU chains. [70] As shown in Figure 3a and Table 1, the hydrogen bonding index R increases from 0.654 for TPU to 0.848 for TPU-3CNTs.…”

Effect of Carbon Black Nanofiller on Adhesion Properties of SBS Rubber Surfaces Treated by Low-Pressure Plasma

“…One of the important ingredients added to the rubber, having a significant impact on its properties, is carbon black (CB) in the form of nanoscale particles. Indeed, the rubber industry has used this modification extensively to improve abrasion resistance, elastic modulus, tensile strength, viscoelasticity as well as rheological and conductive properties of elastomeric composites [17][18][19][20][21][22]. However, despite decades of such technology, the actual mechanisms by which CB nanoparticles modify the macroscale properties of rubbers are still not fully understood [23].…”