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The crystalline behaviors and micromorphology of polymers have a large impact on the physical and mechanical properties, especially for polypropylene (PP) composites with toughening effect. In this work, the changes of the content ratio for layered double hydroxide (LDH) and [beta]-nucleating agent (CaHA), mechanical properties, and crystallization behaviors of PP/ethylene vinyl acetate copolymer (EVA)/LDH ternary composites are investigated by differential scanning calorimeter (DSC), polarizing optical microscopy (POM), scanning electron microscopy (SEM), and notched impact strength testing. The CaHA is used for synergistic toughening with LDH, and the highest notched impact strength is achieved in the 6PEL2 sample with CaHA of 0.03 phr and LDH of 5.70 phr, which is about 100% higher than that of pure PP. It is found from the crystallization behaviors and SEM images of the composites that 6PEL2 has the highest relative content of [beta]-crystals and the appearance of rougher interface and deformation pullout of the EVA phase in 6PEL2 because of dislocations in the [beta]-crystals and the formation of a large number of cavities absorbing the impact energy. KEYWORDS composites, crystallization, polypropylene, toughness, 1 | INTRODUCTION Polypropylene (PP), one of the general-purpose plastics, is used in large quantities due to its excellent corrosion resistance, processability, and low price. [1] Due to the poor [...]

Highly efficient removal of organic dyes in wastewater is attracting more and more attention. Here, a novel 3D flower-like copper(II) oxide hybrid nickel–aluminum layered double hydroxide (CuO@LDH) microsphere with increasing catalytically active sites and specific surface area is fabricated by a hydrothermal method and applied for the degradation and adsorption of organic dyes. The Fenton-like system of CuO@LDH with H2O2 exhibits excellent degradation activity for methylene blue (MB). Moreover, nearly 99.0% degradation of MB is achieved within 120 min, and its degradation rate constants (k) are 20 and 93 times higher than that of NiAl-LDH and H2O2 alone, respectively. Meanwhile, the effect of catalyst dosage, pH, H2O2 dosage, and coexisting ions on MB removal is investigated in detail. CuO@LDH can also effectively adsorb congo red (CR) with a maximum adsorption capacity of 560.3 mg g−1. The degradation mechanism is explored via bursting experiments and electron spin resonance (ESR). The degradation pathway of MB is analyzed based on density functional theory (DFT) calculations and the liquid chromatography-mass spectrometry (LC-MS) technique. The biotoxicity of the intermediates is evaluated using a quantitative structure–activity relationship (QSAR). Therefore, this work is expected to expand the application of LDHs in advanced oxidation processes (AOPs) for wastewater treatment. [ABSTRACT FROM AUTHOR]

Driven by global environmental issues, the development of green building materials has become an immediate focus. In this work, n‐pentane was used as an environmentally friendly blowing agent to prepare flame‐retardant rigid polyurethane foam (RPUF) with the addition of expandable graphite (EG) successfully, and the effect of n‐pentane content on flame retardancy and compressive properties of RPUF/EG composites was investigated through limit oxygen index (LOI), vertical burning test (UL‐94), scanning electron microscope (SEM), thermogravimetric analysis (TGA), and compressive properties test. SEM results show that the content of EG and n‐pentane causes a change in the cell structure of RPUF. The change of the n‐pentane content has also an obvious effect on the thermal stability, flame retardancy, and specific compressive strength of RPUF/EG composites. In addition, the cell structure of RPUF matrix has an obvious influence on the distribution of EG in the composites, which indirectly affects the flame‐retardant efficiency of EG. This research explores the conditions for the application of environmentally friendly RPUF and expands its application prospects. [ABSTRACT FROM AUTHOR]