Enhanced hydrogen gas barrier performance of diaminoalkane functionalized stitched graphene oxide/polyurethane composites

We report the simultaneous reduction, surface modification, and stitching of graphene oxide (GO) by ethylenediamine (EDA) and triethylenetetramine (TET) to boost the hydrogen gas barrier performance of polyurethane (PU) composite-coated nylon films. TEM and XRD analyses confirmed the formation of stitched EDA-modified GO (EDA-mGO) and TET-modified GO (TET-mGO) while FT-IR spectroscopy, Raman spectroscopy, and thermogravimetric analyses revealed the functionalization and reduction of GO by EDA and TET. EDA-mGO/PU and TET-mGO/PU composites were synthesized using different amounts of EDA-mGO and TET-mGO, respectively, and composites were deposited onto surface modified nylon films by spray coating to prepare hydrogen barrier films. FTIR, XRD, and FESEM analyses showed that both EDA-mGO and TET-mGO were uniformly dispersed into PU matrix. Cross-sectional FESEM showed strong adhesion between the nylon and composites. Coated films exhibited dramatic reduction in hydrogen gas transmission rate (H₂GTR) and TET-mGO/PU with 22 wt% TET-mGO exhibited 93% decrease in H₂GTR than bare nylon film.