Improved antibacterial and mechanical performances of carboxylated nitrile butadiene rubber via interface reaction of oxidized starch

[Display omitted] •Oxidized starch featuring significant antibacterial activity was developed by H2O2.•Formed ionic cross-link networks by In-situ interfacial reaction for XNBR/OST/ZnO.•XNBR/OST/ZnO owned antibacterial activity against S. aureus and P. Fluorescens.•Sulfur-free XNBR/OST/ZnO achieved significant increases in mechanical performances. To fabricate antibacterial activity and simultaneous strengthened and toughened carboxylated nitrile butadiene rubber (XNBR) composites, starch was oxidized by H2O2 to achieve oxidized starch (OST) with different carboxyl content, meanwhile, ZnO were utilized to promote the in-situ interfacial reaction for improving compatibility of starch and XNBR. The formation of ionic cross-link networks and “Zinc-carboxylate polymers” in the XNBR/OST/ZnO composites were confirmed by FT-IR, XRD, XPS, SEM-EDS and TEM. Interestingly, because of the carboxyl groups of OSTs which provided a low pH surroundings to inhibit the growth of bacteria, XNBR/OST/ZnO composites achieved a significant antibacterial activity. Noteworthy, the sulfur-free XNBR composites achieved 3.04 and 1.99 times increase for tensile strength and elongation at break compared with neat XNBR. The mechanism of simultaneous strengthened and toughened for composites had been proposed. These new sustainable, green and facile fabricated XNBR/OST/ZnO could be utilized as the medical protective appliance to against the bacteria.