It is challenging to prepare polyurethane bioplastics from renewable resources in a sustainable world. In this work, polyurethane nanocomposite bioplastics are fabricated by blending up to 80 wt % of soy-based polyol and petrochemical polyol with hydroxyl-functionalized multiwalled carbon nanotubes (MWCNTs-OH). The scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR) analyses reveal homogeneous dispersion of the MWCNTs-OH in the matrix, as well as interaction or reaction of MWCNTs-OH with the matrix or polymeric methylene diphenyl diisocyanate (pMDI) in forming the organic–inorganic hybrid bioplastic with a three-dimensional (3D) macromolecule network structure. Mechanical properties and electrical conductivity are remarkably enhanced with the increase of the multiwalled carbon nanotube (MWCNTs) loading. Dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) results show that the bioplastics with MWCNTs-OH have a better thermal stability compared with the bioplastics without MWCNTs-OH. The composition of the nanocomposites, which defines the characteristics of the material and its thermal and electrical conductivity properties, can be precisely controlled by simply varying the concentration of MWCNTs-OH in the polyol mixture solution.

No abstract

Reducing noise by using sound absorption materials is an important approach to lessen the harm of noise pollution. Controlling acoustic performance and analyzing the mechanism of the flexible polyurethane biofoams derived from vegetable oil polyol and filled with agricultural and forestry wastes can provide theoretical guidance in designing the biodegradable energy‐saving sound absorbing materials. A series of biofoams were synthesized by using soy oil‐based polyol instead of 50 wt% petroleum‐based polyol with different content of natural resource bagasse as fillers. The material is characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis to study the morphology, chemical interaction between constituent phases and thermal stability respectively. The effects of bagasse on morphology, mechanical properties, thermal properties, sound absorption coefficient and degradability of biofoams were investigated. Natural resource bagasse can improve the sound absorption coefficient at low frequency region by changing the cell size, opening ratio and cell wall structure of biofoams. The study confirms that it is possible to control and enhance the acoustic performance of the biofoams by adjusting bagasse content for sound absorption materials.

The biobased aromatic triols were designed and synthesized from oleic acid, 10-undecenoic and erucic acid using optimized chemical reactions and purifications. Three aromatic triols were synthesized followed by cyclotrimerization of stearoyl alcohol, 10-undecyn-1-ol, and behenolic ester to obtain the aromatic triols and aromatic derivatives, and subsequent reduction of carboxylate groups to give primary hydroxyl groups. The analyses of these biobased aromatic triols were performed by nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. A series of biobased segmented polyurethanes based on these aromatic triols, 1,4-butanediol as a chain extender and 4,4′-methylenebis(phenyl isocyanate) as a coupling agent, were synthesized. The sample materials were prepared with a hard-segment content up to 50%. The morphologies and thermal stability of these polyurethanes were studied by the FTIR spectroscopy, wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetry-differential thermal analysis (TG-DTA). The results showed that it could be feasible to use the renewable resources to manufacture the applicable and green materials.

No abstract