In this work, a nanofiber mat based on PHB/PEG with various PEG contents was obtained by electrospinning process. The thermal and mechanical properties of the PHB/PEG nanofiber mat were investigated. In addition, PHB/PEG nanofiber mats were characterized by Fourier transforms infrared spectroscopy (FTIR), differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and water contact angle measurement. It was shown that, by increasing the PEG contents from 1 to 4%, the average diameter of PHB nanofibers decreased from 1177 nm to 1101 nm, corresponding to 2% PEG, then the diameter of the fiber increased again from 1101 nm to 1136 nm, corresponding to 4% PEG. Tensile strength increased from 3.6 MPa to 4.4 MPa, then decreased from 4.4 MPa to 2.9 MPa. Thermogravimetric analysis showed a difference in the process of thermal degradation of nanofiber mats. The degree of crystallinity measured by XRD and DSC methods gives different values at some points. The results demonstrated that adding PEG improved the mechanical properties, hydrophobicity, porosity, and thermal stability of the PHB fiber mat, which showed that the PHB/PEG nanofiber mat has great potential for air filtration or water filtration.

In this work, the fabrication process of electrospun nanofibers from a blend of polyhydroxy butyrate (PHB) and polyvinyl chloride (PVC) has been investigated. PVC/PHB nanofibers have been fabricated from solutions using different PVC and PHB ratios. The influence of technical parameters of the electrospinning process on the fabrication, morphology, and diameter of nanofibers has been evaluated. The chemical structure and thermal properties of PVC/PHB have been studied. The results show that the diameter of PVC/PHB nanofibers increases as the PHB content increases. In addition, the optimal technical parameters of the electrospinning process for each PVC and PHB ratio are different. Infrared spectroscopy analysis revealed an enhancement of the crystalline phase of the polymer composite with increasing PHB content. The thermal properties of PVC/PHB nanofibers were evaluated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The change in PHB ratios leads to a change in the glass transition temperature of PVC/PHB nanofibers. The thermal degradation process of PVC/PHB includes two steps. Increasing the PHB content leads to an enhancement in the mechanical strength of PVC/PHB nanofiber mats; however, it also results in a reduction in tensile elongation. Based on the results of structural, morphological, interaction analysis, and mechanical properties of PVC/PHB nanofibers, this study contributes to the optimization of the fabrication of nanofibers from PVC and PHB. PVC/PHB nanofibers have the potential to be used for air filtration applications.

Rubbers based on nitrile butadiene rubber BNKS-40 were obtained using synthesized epoxy methacrylates. The elastic-strength characteristics of the elastomers before and after exposure in a tropical climate were determined. It was shown that the synthesized epoxy methacrylates can be used as temporary plasticizers and co-agents for peroxide vulcanization in elastomer-oligomer compositions.