Table 3.
Enhanced Physicochemical Properties of PU Nanocomposites and Their Main Applications
| NM | PU Type | Size (nm) | Filler Loading | Modification Method | Elastic Modulus | Tensile Strength | Elongation at Break | Properties | Application | Ref. |
|---|---|---|---|---|---|---|---|---|---|---|
| Black phosphorus | Piperazine-based PU | 375 ± 95 | 0.08 wt% | Emulsion mixing | NA | NA | NA | Increases shape recovery rate of ~100% under 808 nm light irradiation and degradability | Smart implantable devices | [96] |
| CS/TiO2 NPs | Polyether based thermoplastic PU | 141.2 (CS); <25 (TiO2) | 5% | Emulsion mixing | NA | 5.40 MPa | 300–400% | Increases swelling ratio up to 5 times and 18.94% tensile strength compared to neat PU | Wound dressing | [1] |
| fMWCNTs | PU/Silk-fibroin | NA | 3 wt% | Emulsion mixing | NA | 16.21 MPa | NA | Increases porosity, mechanical strength, and hydrophilicity | Nerve regeneration | [78] |
| GNP | Poly(e–caprolactone)diol/castor oil/hexamethylene diisocyanate | 35–56 | 1.5 wt% | In situ polymerization | 35.11 MPa | 70–121 MPa | 120–550% | Elastic modulus increases of 1.97–2.73 GPa with tensile strength increases | Cardiovascular devices | [97] |
| MWCNTs | Poly(aliphatic/aromatic-ester) | Outer diameter 13 nm, inner diameter of 4 nm | 0.33% | Emulsion mixing | NA | (11.40 ± 0.9)-(51.25 ± 5.5) MPa | NA | Increases mechanical properties of the nanofibers and increases in porosity. | Tendon and ligament grafts | [80] |
| Polypropylene glycol wrapped nHA | Polycarbonate based TPU | 500 | 1 wt% | In situ | 0.6 MPa | 19.5 MPa | 395% | ~124% increases in Young’s modulus, 149% increases in tensile strength | Soft and hard tissues implants | [5] |
| POSS NPs | PU foam hybrids | NA | 5 wt% | Emulsion mixing | 48.8 ± 3.2 Mpa (Young) | 40 MPa | NA | Increases hardness (on average by 0.46 KPa) | Bone tissue engineering | [98] |
| γ-Fe2O3-NPs | TPU/PLLA | NA | 3% w/v | Emulsion mixing | 28.49–35.11 MPa | 6.86–7.76 MPa | NA | 90.72% porosity, 24% increases in elastic modulus | Aortic heart valve | [72] |
Abbreviations: γ-Fe2O3, γ-iron oxide; CS, chitosan; fMWCNTs, functionalized multi-walled carbon nanotubes; GNP, gold nanoparticle; MWCNTs, multi-walled carbon nanotubes; nHA, nano-hydroxyapatite; NM, nanomaterial; NPs, nanoparticles; PLLA, poly-l-lactic acid; POSS, polyhedral oligo-sesquioxane; PU, polyurethane; TiO2, titanium dioxide; TPU, thermoplastic polyurethane.