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The highly stretchable and ultrasensitive TPU/CNTs porous sensors with anisotropic pores have been fabricated efficiently for human motion monitoring.

Superhydrophobic silicone rubbers with robust physical and chemical stability have promising application potential in the field of flexible electronics. A one-step laser etching strategy is proposed for successfully fabricating superhydrophobic silicone rubbers with bioinspired hierarchical micro/nanostructures. Regular and dense micro/nano spheres gradually accumulate on the modified silicone rubber surface with the increase of laser etching cycles. Owing to the bioinspired hierarchical micro/nano spheres, a 5 μL water droplet on the modified silicone rubber surface exhibits a contact angle of 158 ± 3° and a sliding angle of 5 ± 1°. Moreover, the modified silicone rubber can maintain a stable superhydrophobic state in acid/alkali (pH = 2, 4, 6, 8, and 10) and thermal environments (50-90 °C). Importantly, the contact angle and sliding angle are adjustable depending on the number of laser etching cycles, which is beneficial for the different application requirements. The proposed method for the fast fabrication of superhydrophobic silicone rubbers with tunable wettability can provide an excellent candidate for the protection of flexible electronics in rainy and acid/alkali environments.

Poly(lactic acid) (PLA) as one of the most promising biodegradable polymers is being tremendously restricted in large-scale applications by the notorious toughness, ductility, and heat distortion resistance. Manufacturing PLA with excellent toughness, considerable ductility, balanced strength, and great heat distortion resistance simultaneously is still a great challenge. Natural structural materials usually possess excellent strength and toughness by elaborately constructed sophisticated hierarchical architectures, however, completely reproducing natural structural materials' architecture have evidenced to be difficult. Inspired by the hierarchical construction of the compact bone, an innovational method with an intensive and continuous elongational flow field and facile annealing process was developed to create bone-mimicking structured PLA at an industrial scale. The bone-mimicking structured PLA with unique and novel hierarchical architectures of interlocked 3D network lamellae and large extended-chain lamellae connecting the regular lamellae was constructed by in situ formed oriented thermoplastic poly(ether)urethane nanofibers (TNFs) acting as "collagen fibers", orderly staggered PLA lamellae behaving as "hydroxyapatite (HA) nanocrystals", and the tenacious interface functioning as a "soft protein" adhesive layer. Attributed to the unique structure, it possesses super toughness (90.3 KJ/m2), high stiffness (2.15 GPa), balanced strength (52.6 MPa), and notable heat distortion resistance (holding at 163 °C for 1 h) simultaneously. These excellent performances of the structured PLA provide it with immense potential applications in both structural and bio-engineering materials fields such as artificial bones and tissue scaffolds.

In this work, poly (lactic acid) (PLA) and elastomer ethylene-butyl acrylate-glycidyl methacrylate terpolymer (EBA-GMA) containing epoxy groups were melt-blended using a novel vane extruder...

The hollow glass beads (HGB) was melt blended with biodegradable poly (lactic acid) (PLA) and intumescent flame retardant (IFR) by twin-screw extruder (TSE) to improve the flame retardancy. The flame retardant properties and thermal stability of biodegradable PLA/IFR/HGB composites were investigated by limiting oxygen index (LOI), vertical burning (UL-94), cone calorimeter tests (CCT) and thermogravimetric analysis (TGA). The result of the LOI can be as high as 35.5% with only 2% HGB and 10% IFR addition. And the thermal stability of the PLA/IFR blends were enhanced by the partial substitution of IFR with HGB. The lowest peak of heat release rate (pHRR) was achieved by introduction of 1 wt% HGB, with a remarkable decrease in pHRR (72.3%). What's more, the residues of PLA/IFR/HGB composites after CCT were characterized by scanning electron microscope–energy dispersive spectrometer (SEM–EDS) and laser Raman spectroscopy (LRS). All the results revealed that the addition of HGB had synergistic effect on the flame retardancy of PLA/IFR composites.

In this study, novel shape-stabilized phase change materials (SSPCMs) were first prepared via melt blending by employing bio-based poly (lactic acid) (PLA) as the supporting matrix and high-density polyethylene (HDPE) as the phase change working substance for thermal energy storage (TES) applications. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results indicated that no chemical reaction occurred between PLA and HDPE during melt processing, but the crystalline regions of HDPE was decreased by the introduction of PLA component. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and shape stability tests showed that the PLA50/50HDPE blend with co-continuous phase morphology had good shape stability and thermal energy storage capacity. The co-continuous structure of un-melted PLA component in the PLA50/50HDPE blend could provide strong support for the HDPE component and maintain its shape during the phase change process. The latent heat for the PLA50/50HDPE blend during melting and freezing process are 100.1 J/g and 97.6 J/g, respectively, and the relative enthalpy efficiency reaches as high as 104.2%. After 10 thermal cycles, the thermal parameters of PLA50/50HDPE blend remain nearly constant. It indicated that the PLA50/50HDPE blend as SSPCM had excellent reusability and thermal reliability. The simple thermal energy storage and conversion experiments showed that the PLA50/50HDPE SSPCM owns great potential in solar energy storage or industrial waste heat recovery field.

Improving the processability of ultrahigh molecular weight polyethylene (UHMWPE) and understanding the effect of the polymeric chain mobility has long been a challenging task. Herein, we show that UHMWPE without any processing aids can be processed at a lower temperature of 180 °C compared to conventional processing temperatures (~250 °C) under a continuous elongational flow (CEF) by using an eccentric rotor extruder (ERE). By probing the effect of the residence time of UHMWPE samples under a CEF on the morphology, rheological behavior and molecular orientation, we find that the long polymer chains of UHMWPE are apt to orientate under a consecutive volume elongational deformation, thereby leading to a higher residual stress for the extruded sample. Meanwhile, the residence time of samples can regulate the polymeric chain mobility, giving rise to the simultaneous decrease of the melting defects and residual stress as well as Hermans orientation function with increasing residence time from 0 to 60 s. This also engenders the enhanced diffusion of UHMWPE segments, resulting in a defect-free morphology and higher entanglement with lower crystallinity but without causing obvious thermal oxidative degradation of UHMWPE. This interesting result could originate from the fast chain entanglement and particle welding enabled by a desirably short residence time, which could be explained by the empirical, entropy-driven melting explosion mechanism.

With the rapid advance of electronics, the light, flexible, and multifunctional composite films with high electromagnetic interference (EMI) shielding effectiveness and excellent thermal management are highly desirable for next-generation portable and wearable electronic devices. Herein, a series of flexible and ultrathin natural rubber/MXene/carbon nanotubes (NR/MXene/CNTs) composite films with sandwich structure are constructed layer by layer through a facile vacuum-assisted filtration method for EMI shielding and Joule heating application. The fabricated NR/MXene/CNTs-50 composite film, with NR/MXene as inner layer and NR/CNTs as out layers, not only has high EMI shielding efficiency, but also has excellent comprehensive mechanical properties at the thickness of only 200 µm. In addition, the superior environmental durability, high electrothermal conversion efficiency, hydrophobicity, and fine performance stability after periodic cyclic bending make the film possess more value in practical application.