Latex co‐coagulation approach to fabrication of polyurethane/graphene nanocomposites with improved electrical conductivity, thermal conductivity, and barrier property

Abstract

This study describes a simple and effective method of synthesis of a polyurethane/graphene nanocomposite. Cationic waterborne polyurethane (CWPU) was used as the polymer matrix, and graphene oxide (GO) as a starting nanofiller. The CWPU/GO nanocomposite was prepared by first mixing a CWPU emulsion with a GO colloidal dispersion. The positively charged CWPU latex particles were assembled on the surfaces of the negatively charged GO nanoplatelets through electrostatic interactions. Then, the CWPU/chemically reduced GO (RGO) was obtained by treating the CWPU/GO with hydrazine hydrate in DMF. The results of X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Raman analysis showed that the RGO nanoplatelets were well dispersed and exfoliated in the CWPU matrix. The electrical conductivity of the CWPU/RGO nanocomposite could reach 0.28 S m−1, and the thermal conductivity was as high as 1.71 W m−1 K−1. The oxygen transmission rate (OTR) of the CWPU/RGO‐coated PET film was significantly decreased to 0.6 cm3 m−2 day−1, indicating a high oxygen barrier property. This remarkable improvement in the electrical and thermal conductivity and barrier property of the CWPU/RGO nanocomposite is attributed to the electrostatic interactions and the molecular‐level dispersion of RGO nanoplatelets in the CWPU matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43117.

Molecular Dynamics Simulation-Based Study on Enhancing Thermal Properties of Graphene-Reinforced Thermoplastic Polyurethane Nanocomposite for Heat Exchanger Materials

“…Due to the presence of the graphene-TPU interface, there exists a temperature jump ΔT at the interface. The present study obtained values are in good agreement with previous values obtained from simulations and experimental measurements in the literatures [26][27][28][29][30][31]. The present study contributes some novel procedures during MD simulation work which will not be done in previous researchers.…”

Challenges in Liquid‐Phase Exfoliation, Processing, and Assembly of Pristine Graphene

“…One of the chief applications for graphene is conductive and/or reinforcing filler for polymer composites; graphene also impacts other functional properties as an additive, with notable advancements in barrier properties or thermal transport. [142][143][144] In this section, we review the challenges and opportunities related to the use of pristine graphene in polymer composites, and we compare composite processing and properties against those using GO and rGO.…”

High-yield scalable graphene nanosheet production from compressed graphite using electrochemical exfoliation

“…Graphene, i.e., a single layer of sp 2 -hybridized carbon, is rightly touted for its superlative material properties and has been demonstrated both as a novel building block and as an additive for a wide range of multifunctional materials 1 , 2 . Such materials are used for energy storage, structural composites, and advanced electronics 3 – 9 . Industry reports estimate that graphene demand will reach over 4100 tons/year by 2026 10 .…”