Sustainable and greener coatings produced from accelerator‐ and sulfur‐free polyurethane dispersion/carboxylated nitrile butadiene latex blends

Abstract This study is aimed at producing polyurethane dispersion (PUD)/carboxylated nitrile butadiene rubber (XNBR) blends without using accelerators and sulfur. The PUD/XNBR (at blending ratios of 90:10, 80:20, 70:30, and 60:40) was prepared using coagulation and latex dipping technology. The result demonstrated that increasing XNBR in the PUD/XNBR blends increased the zeta potential of the blends up to −71.8 mV. Fourier transform infrared (FTIR) studies show hydrogen interaction bonding exists between XNBR and PUD, which significantly impacts the degree of phase mixing, degree of phase separation and relative change of hard segment separation of the PUD. The surface energy of the PUD blend is reduced from 34.68 ± 0.23 to 22.28 ± 0.63 mJ −2 with increasing XNBR loading. The presence of XNBR had increased the polar component of the surface energy, but a further increase of the XNBR amount to more than 20% had reduced the tensile strength. Overall, loading 20% of XNBR (PUD80) showed the best performance by having an improvement in tensile strength compared to pristine PUD.