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The microphase separation behavior of polyurethane (PU) strongly affects its mechanical, thermal, electrical, and other functional properties. Adding fillers to change the degree of microphase separation (DPS) in PU is a convenient and efficient method. Although many scholars have tried to regulate the microphase separation of PU by adding fillers, there are still many controversies about the effect. In this review, we classify commonly used fillers into three categories according to their morphology: spherical fillers, fibrous fillers, and layered fillers, and summarize their effects on the microphase separation behavior of PU. We explore the similarities and differences in the mechanisms by which different fillers affect the microphase separation of PU, and find that the polarity, morphology, size of fillers, and preparation method have a significant impact on the degree of microphase separation in PU. The impact of microphase separation on the mechanical properties of PU has also been summarized to illustrate their close relationship. We hope that these summaries will provide some guidance for the development of new high-strength and multifunctional PU composites. Highlights * Summarized recent research progress on effect of common fillers on DPS of PU. * Common fillers are classified into three categories based on their morphology. * Common laws of the fillers impact on the DPS are classified and discussed. * The close relationship between DPS and mechanical properties is reviewed. * Provided information for high-strength and multifunctional PU development. KEYWORDS different fillers, filler polarity, hard segment microdomains, hydrogen bonding, microphase separation, polyurethane, 1 | INTRODUCTION Polyurethane (PU) is a block copolymer composed of hard and soft segments. The hard segment (HS) is composed of diisocyanate, chain extender, and urethane group or urea [...]

Silicon oxycarbide (SiOC) is a promising anode material for lithium‐ion batteries, owing to the high capacity and superior structural stability. However, the application of SiOC anode is limited by its low conductivity and poor rate performance. Here, SiOC anodes were prepared by the pyrolysis of silicone resin (RSN‐217) at different temperatures (700, 850, 1000, and 1150° C), and the effect of graphitization degree and Si─O─C network on the electrochemical performance of SiOC anodes was investigated. The elemental and structural characteristics of the pyrolyzed SiOC ceramics at different temperatures were inspected using a broad spectrum of characterization techniques, and electrochemical performance testing methods, such as cyclic voltammetry and galvanostatic charge/discharge, were conducted on SiOC anode. SiOC‐1000 showed excellent electrochemical performance due to the highest graphitization degree of free carbon phase and the highest content of SiO2C2 and SiO3C units. Considerable research effort laid a foundation for exploring the lithium storage mechanism of SiOC anode. [ABSTRACT FROM AUTHOR]

On the basis of carbon tetrachloride (CCl4)induced liver fibrosis in rats, this study aims to investigate the dynamic changes in matrix metalloproteinase 1 (MMP1) and the tissue inhibitor of metalloproteinase 1 (TIMP1) in the antifibrotic process of Dahuang Zhechong Pill (DHZCP). A total of 50 male Sprague Dawley rats, aged 8 weeks, were randomly divided into 3 groups: the control group, the model group (the group treated with CCl4), and the treatment group (the group treated with CCl4 and DHZCP). Rats were sacrificed at Weeks 4 and 8. Liver tissues were separated for RNA sequencing and bioinformatics analysis. Real-time PCR, Western blot analysis, and histological staining were conducted to confirm the gene expression and pathological change in liver tissues. Compared with control group, rats in model group showed poor mental state and slow weight gain. The liver tissues of the rats in the model group exhibited a damaged hepatic lobule structure, fibrous connective tissue hyperplasia, and inflammatory cell infiltration among the hyperplastic tissues. DHZCP could significantly improve the appearance of rats and alleviate CCl4-induced fibrosis. Compared to model group, 798 differentially expressed mRNAs were found in the treatment group, of which 120 were up-regulated and 678 were down-regulated. Differentially expressed mRNAs between the CCl4-induced group and the DHZCP-treated group were mainly focused on the following KEGG pathways: focal adhesion, phagosome, tight junction, and ECM–receptor interactions. Relative to those in the control group, MMP1 was downregulated, whereas, TIMP1 and Col1A1 were upregulated in the CCl4-induced group at Weeks 4 and 8. DHZCP could reverse MMP1, TIMP1, and Col1A1 expression.DHZCP protects against liver injury and exerts an antifibrotic effect on liver fibrosis induced by CCl4 in rats. Its mechanism may be related to the upregulation of MMP1, downregulation of TIMP1, and promotion of collagen degradation.

Although there have been some studies on the preparation and characteristics of nano‐Fe3O4‐filled polyurethane (PU) composites, research focusing on the quantitative influence of the degree of microphase separation (DPS) and the crosslinking density (CLD) on dynamic viscoelastic properties is rare. In this paper, PU composites are synthesized by incorporating nano‐Fe3O4 as fillers. The dynamic mechanical properties under alternating loads are investigated using dynamic mechanical analysis. The influences of the DPS and the CLD on the dynamic hysteresis loss are analyzed. The experimental results show that the DPS and CLD of PU nanocomposites increase and then decrease with the increase of nano‐Fe3O4 addition and reached a maximum at the addition amount of 1.0 wt%. The quantitative relationships between DPS, CLD and the dynamic hysteresis loss of PU nanocomposites at different filler ratios are obtained. With a 1.0 wt% nano‐Fe3O4 content, the strain energy density (SED) and hysteresis energy density (HED) are increased by 416% and 354%, respectively. The hysteretic loss H indexes of all composites are kept lower than that of pure PU. These characteristics make nano‐Fe3O4‐filled PU a promising material for reducing the rolling resistance and increasing the service life of fuel‐saving tire materials. [ABSTRACT FROM AUTHOR]