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In this paper, the crystalline modification of isotactic polypropylene (PP) with a rare earth β nucleating agent (WBG) with different ultrasound conditions was investigated by scanning electron microscopy (SEM), wide-angle X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The relationship between the ultrasound conditions and the crystalline structure, as well as the mechanism for the behavior, were revealed. SEM showed that the dispersion of the nucleating agent in the PP matrix was better at shorter ultrasound distances. In addition, the higher the water cooling temperature, the better the nucleating agent was dispersed in the PP matrix. The results of XRD and DSC showed that the crystallinity and the relative content of the β -crystal were increased with nearer ultrasound distance, as well as increased in higher water cooling temperatures. In particular, under the same conditions, the crystallinity and the relative content of the β -crystal after ultrasonic treatment were much higher than those without ultrasound., Competing Interests: The authors declare no conflict of interest.

Abundant studies have been completed about factors on the pyrolysis of coal and biomass. However, few articles laid emphasis on using CO 2 as a carrier gas to explore the compositional changes of pyrolysis products in coal and biomass pyrolysis for industrial application and commercial value. The experiments on coal and biomass pyrolysis in N 2 and CO 2 using a horizontal tube furnace were conducted at 500 °C. The impact of introducing CO 2 on the pyrolysis process of bituminous coal and Platanus sawdust was investigated. The nuclear magnetic resonance (NMR) spectra of tar and the characterizations of char including Brunner-Emmet-Teller (BET) measurements, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, and element analysis were studied. The findings in light of the experimental results show that introducing CO 2 enhances the coal and biomass pyrolysis in a solid product by promoting the fracture of hydroxyl groups. It also promotes tar decomposition and the release of volatiles, which contribute to the occurrence of char with high porosity, pore volume, and specific surface. Furthermore, higher specific surface enhances the adsorption performance of char as active carbon. Simultaneously, CO 2 promotes the increase of oxygen-containing aromatics especially the methoxy-containing aromatics, and the decrease of deoxygenated aromatic hydrocarbons in pyrolysis oils. In addition, the introduction of CO 2 changes the amount of aliphatic compounds in various ways for the pyrolysis of coal and biomass. From a perspective of business, the changes in the composition of pyrolysis oil brought by CO 2 may create new value for fuel utilization and industrial products.

Artemisia vulgaris is an economic plant that is spreading widely in central China. Its unused bast generates a large amount of biomass waste annually. Utilizing the fibers in Artemisia vulgaris bast may provide a new solution to this problem. This research attempts to strengthen the understanding of Artemisia vulgaris by analyzing its fiber compositions and preparing micro- and nano-cellulose fibers, which can be used as raw materials for composites. In this work, Artemisia vulgaris bast powder (AP) and microcellulose and nanocellulose fibers (AMFs and ANFs) were produced and characterized by optical microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TG), and bacteriostatic test. The results indicated that cellulose, hemicellulose, and lignin were the main components in the Artemisia vulgaris bast. The cellulose content reached 40.9%. The Artemisia vulgaris single fibers were microcellulose fibers with an average length of 850.6 μm and a diameter of 14.4 μm. Moreover, the AMF had considerable antibacterial ability with an antibacterial ratio of 36.6%. The ANF showed a length range of 250-300 nm and a diameter of 10-20 nm, and it had a higher crystallinity (76%) and a lower thermal stability (initial degradation temperature of 183 °C) compared with raw ANF (233 °C). This study provides fundamental information on Artemisia vulgaris bast cellulose for its subsequent utilization., Competing Interests: The authors declare no conflict of interest.