Bio-based hyperbranched polyurethane/Fe3 O4 nanocomposites as shape memory materials

Nonedible Vegetable Oil-Based Polyols in Anticorrosive and Antimicrobial Polyurethane Coatings

This review describes the preparation of nonedible vegetable oil (NEVO)-based polyols and their application in anticorrosive and antimicrobial polyurethane (PU) coatings. PUs are a class of versatile polymers made up of polyols and isocyanates. Renewable vegetable oils are promising resources for the development of ecofriendly polyols and the corresponding PUs. Researchers are interested in NEVOs because they provide an alternative to critical global food issues. The cultivation of plant resources for NEVOs can also be popularized globally by utilizing marginal land or wastelands. Polyols can be prepared from NEVOs following different conversion routes, including esterification, etherification, amidation, ozonolysis, hydrogenation, hydroformylation, thio-ene, acrylation, and epoxidation. These polyols can be incorporated into the PU network for coating applications. Metal surface corrosion and microbial growth are severe problems that cause enormous economic losses annually. These problems can be overcome by NEVO-based PU coatings, incorporating functional ingredients such as corrosion inhibitors and antimicrobial agents. The preferred coatings have great potential in high performance, smart, and functional applications, including in biomedical fields, to cope with emerging threats such as COVID-19.

Preparation and properties of polyimide-based nanocomposites containing functionalized Fe3O4 nanoparticles

Polyimide (PI)/Fe3O4 nanocomposites were successfully prepared via the thermal curing of different amounts of Fe3O4 nanoparticles (2, 4, 6 and 8 wt%) functionalized by 3-aminopropyltriethoxy silane as a coupling agent, containing the poly(amic acid) derived from 5-diamino- N-(4-(4,5-diphenyl-1H-imidazol)phenyl)benzamide and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride. The effect of Fe3O4 nanoparticles on the structural, thermal and magnetic properties of nanocomposites was investigated. The Fourier transform infrared spectroscopy and scanning electron microscopy (SEM) results reveal that the surface of Fe3O4 nanoparticles is sufficiently compatible with PI through linkage of the coupling agent between Fe3O4 and the polymer. Also, the SEM image shows that Fe3O4 nanoparticles are dispersed uniformly in the polymer matrix, with a particle size of around 78 nm. The nanocomposites of 2 and 8 wt% exhibit the saturation magnetization values of 0.055 and 0.170 emu g− 1, respectively. The thermogravimetric analysis data show that the thermal stability of the nanocomposites is improved as compared to the pure PI.

Self-healable castor oil based tough smart hyperbranched polyurethane nanocomposite with antimicrobial attributes

Smart, tough hyperbranched polyurethane nanocomposite with excellent rapid and repeatable self-healing and antimicrobial attributes is fabricated.