No abstract

Polyamide 6 (PA6)/CeO2 composite nanofibers were prepared by electrospinning technique. The morphological, structural, and mechanical properties of the PA6/CeO2 nanofibers were investigated by using SEM, XRD, Fourier transform-infrared (FT-IR) spectroscopy, and an electronic universal tensile testing machine. SEM images revealed that the nanofibers were well oriented and had good incorporation with CeO2, the average diameter of composite fibers first decreases and then increases with the loading of CeO2. The crystallinity of fibers decreases after the addition of CeO2. The tensile strength of the fibers first increases and then decreases with the increasing concentration of CeO2. The proliferation properties of mouse macrophages and osteoblasts on the PA6/CeO2 nanofibers were analyzed by an in vitro cell compatibility test, the results show that PA6/CeO2 composite fibers is nontoxic to macrophages and osteoblasts and has good biocompatibility.

An in situ modification method is used to synthesize a new type of phenolic resin-based composite material used to fill goafs and seal air leaks in roadways. This was followed by scanning electron microscopy, oxygen index, and compression tests. The results show that when the aluminium hydroxide, Sd-31 silicone oil and methylene chloride are added to the phenolic resin in a mass fraction ratio of 8%:5%:3%, the overall performance of the composite material is the best. Compared with unmodified phenolic resin, the oxygen index and compressive strength of thecomposite material are increased by 40.16% and 3.5 times, respectively. The maximum reaction temperature of foaming and curing is also reduced from 120.3 to 87.2°C. To verify the performance of the new material, field tests were carried out at Matigou coal mine in Gansu, China. The average air leakage rate of the working face was reduced from 12.8 to 2.1 %.

No abstract

No abstract