A novel epoxy thermoset is synthesized with dynamic SiOSi bonds. The thermosetting epoxy resins possess excellent reprocessing, reshaping, and shape memory ability due to the special molecular structure. The material exhibits high tensile strength and a fast stress relaxation process. Surprisingly, it can achieve complete healing and keep stable mechanical property after multi‐processing.

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The incorporation of carbon nanotubes into catalyst-free thermoset polyurea composites can achieve their excellent reprocessability by hot press or micro injection.

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The all-fiber self-mixing laser Doppler velocimetry with adjustable gain is experimentally investigated based on a distributed Bragg reflector fiber laser. In the measurement system, the modulation gain of the injected light in the laser cavity is adjusted by a pair of fiber-coupled acousto-optic modulators (AOMs) in the external cavity, which can change the intensity and frequency of the self-mixing modulation effect. Simultaneously, the minimum feedback intensity from the target to the laser for successful measurements is 0.063 pW. Thus, the all-fiber laser velocimetry can adapt to the detection of ultraweak optical feedback and wide-range velocity measurements in various complex scenes.

The utilization of renewable energy through phase change materials (PCMs) is particularly attractive for the realization of sustainable society. Herein, a flexible but reliable solid–solid PCM was successfully synthesized by the integration of quadruple H‐bonding crosslinks with polyethylene glycol (PEG)‐based polyurethanes. The strong quadruple H‐bonding from the dimerization of 2‐ureido‐4 [1H]‐pyrimidinone (UPy) units could act as dynamic cross‐links to maintain shape stability. PEG chains in flexible polymer network serve as phase change ingredients, affording thermal energy storage capacity. The physical crosslink density and phase change enthalpy can be adjusted. In contrast to chemical crosslinks, the physical crosslinks of UPy provide reprocessability of the prepared PCMs and show little hindrance on the crystallization of PEG chains. The chemical structure, phase transformation, crystallization, and thermal properties of prepared PCMs were characterized by fourier transform infrared spectroscopy, differential scanning calorimetry (DSC), X‐ray diffraction, polarizing microscope, and thermogravimetric analysis. DSC analysis shows that the prepared PCM can store 101.9 J g−1 when PCMs undergo phase change process. Moreover, the accelerated thermal cycling test and leakage test are also conducted to illustrate the thermal reliability and shape‐stable properties. These PCMs that possess high phase change enthalpy and outstanding reprocessability are alternative for solar energy collection and waste heat recovery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48497.

We prepared a temperature‐responsive polyurethane (PU) with a coil‐to‐globule transition temperature of 36°C in aqueous media, by using polyethylene glycol‐4,000 (PEG‐4000), polycaprolactone diol‐1,000 (PCL‐1000), diphenylmethane diisocyanate‐50, and hydroxyethyl acrylate. Nanohydrogels were synthesized from temperature‐responsive PU through precipitation polymerization without employing a crosslinker. Due to the unique molecular structure of temperature‐responsive PU, PU nanohydrogels have uniform cross‐linking networks resulting in narrow volume phase transition temperature range, showing sensitive temperature responsiveness. Additionally, PEG and PCL segments provide PU nanohydrogels excellent biocompatibility and biodegradability, respectively. POLYM. ENG. SCI., 59:1517–1523 2019. © 2019 Society of Plastics Engineers