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Demand for high‐performance electromagnetic (EM) wave absorbing materials with high‐temperature resistance is always urgent for application in a harsh environment. In this contribution, two‐dimensional material, Ti3C2Tx MXene, was introduced into a hyperbranched polyborosilazane. After pyrolyzation, the as‐prepared TiC/SiBCN ceramics present excellent EM wave absorption in X‐band. The TiC nanograins appearing after annealing provide multilevel reflection and interface polarization. Dipole polarization formed at interface defects, in company with interfacial polarization, also makes a great contribution to enhanced EM wave absorption. The TiC/SiBCN nanocomplex prepared with 5 wt% Ti3C2Tx MXene possesses a minimum reflection coefficient of −45.44 dB at 10.93 GHz and abroad bandwidth 8.4 and 12.4 GHz, almost covering the entire X‐band. Tuning the thickness in the range of 2.35‐2.54 mm, the effective absorption band can achieve the entire X‐band. And the EM wave absorbing performance has been maintained to a large extent at 600°C with the minimum reflection coefficient of −26.12 dB at 12.13 GHz and the effective absorption bandwidth of 2 GHz. Last but not the least, TiC/SiBCN ceramics offer a good thermal stability in argon as well as in air atmosphere, making it possible to serve in high‐temperature detrimental environments. This study is expected to provide a new perspective for the design of high‐performance absorbing materials that are able to be used in harsh environments, especially in high temperatures. [ABSTRACT FROM AUTHOR]

Antioxidants are necessarily used in nitrile butadiene rubber (NBR) products to prolong their lifetimes. But blooming of antioxidants limits the anti‐aging efficiency. Herein, a novel solution was proposed to avoid such a blooming. Antioxidant, 3, 9‐bis‐{1, 1‐dimethyl‐2(β‐[3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl‐] propionyloxy) ethyl}‐2, 4, 8, 10‐tetraoxaspiro [5, 5]‐undecane (AO‐80) was loaded to carbon nanotubes (CNTs) by chemically grafting after shearing force and then physically melting to encapsulate. In the AO‐80 loaded CNTs (CNT‐AO80), physical loading amounts of antioxidants were 2.1% and strongly suppressed by those parts from chemically grafting (13.9%), developing a distribution around CNTs. CNT‐AO80 therefore maintained a high total loading efficiency of antioxidant and reduced its physical release amounts not to bloom. When 20 phr CNT‐AO80 were doped to NBR, they allowed a good dispersity and reinforcement for rubber matrix. After thermal‐oxidative aging at 70, 80, and 90°C for 60 days, the composite gave an extremely low deterioration of mechanical property. POLYM. COMPOS., 40:E1172–E1180, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Present conductive silicone rubber with carbon blacks has low compression recovery, and is difficult to make long‐term electromagnetic shielding products. In order to solve the problem, special hollow‐shell carbon blacks were used and then treated by coupling agent to prepare conductive silicone rubber. The compression set of conductive rubber at 100°C for 48 h was only 8.9%, displaying a extremely good recovery. Importantly, the special rubber can be extruded and then continuously vulcanized. Moreover, its electromagnetic shielding effectiveness reached beyond 20 dB at the frequency of 0.01 MHz–10 GHz. After the thermal oxidative aging at 90 and 110°C for 30 days, carbon blacks occurred to aggregate, which gives rise to a drop of tensile property and slight effects on the modulus and hardness. The compression set also increased, but it still maintained a low level after 30 days. There is only little change for the conductivity of silicone rubber and thus its electromagnetic shielding effectiveness still retained beyond 20 dB, showing a good aging resistance. It is believed that our findings may provide an effective solution to fabricate rubber products to sever the electromagnetic protection. POLYM. COMPOS., 40:1078–1086, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The influence of household demographic composition on rural migration in China has received limited attention. With data from a household survey in China's Sichuan and Hubei Provinces, this paper uses Probit models to explore the influence of household structure on migration decisions. It suggests that the three-generation household encourages out-migration, with the elderly playing an important role in supporting the migration of younger members by caring for their children. In contrast with earlier findings, the serious illness of an elderly member did not encourage the return of young migrants or discourage migration decisions unless the household included young children. [ABSTRACT FROM AUTHOR]