FOAMING AND MOISTURE CROSSLINKING OF VINYL TRIETHOXY SILANE GRAFTED ETHYLENE–PROPYLENE–DIENE TERPOLYMER

Author(s):  
Zhengwei Lin ◽  
Qinghong Zhang ◽  
Gongliang Wang ◽  
Jie Mao ◽  
Martin Hoch ◽  
...  

ABSTRACT Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhuolin Tang ◽  
Mengming Yuan ◽  
Huali Zhu ◽  
Guang Zeng ◽  
Jun Liu ◽  
...  

Nowadays, Li–CO2 batteries have attracted enormous interests due to their high energy density for integrated energy storage and conversion devices, superiorities of capturing and converting CO2. Nevertheless, the actual application of Li–CO2 batteries is hindered attributed to excessive overpotential and poor lifespan. In the past decades, catalysts have been employed in the Li–CO2 batteries and been demonstrated to reduce the decomposition potential of the as-formed Li2CO3 during charge process with high efficiency. However, as a representative of promising catalysts, the high costs of noble metals limit the further development, which gives rise to the exploration of catalysts with high efficiency and low cost. In this work, we prepared a K+ doped MnO2 nanowires networks with three-dimensional interconnections (3D KMO NWs) catalyst through a simple hydrothermal method. The interconnected 3D nanowires network catalysts could accelerate the Li ions diffusion, CO2 transfer and the decomposition of discharge products Li2CO3. It is found that high content of K+ doping can promote the diffusion of ions, electrons and CO2 in the MnO2 air cathode, and promote the octahedral effect of MnO6, stabilize the structure of MnO2 hosts, and improve the catalytic activity of CO2. Therefore, it shows a high total discharge capacity of 9,043 mAh g−1, a low overpotential of 1.25 V, and a longer cycle performance.


2020 ◽  
Vol 117 (21) ◽  
pp. 11240-11246 ◽  
Author(s):  
Shuwang Wu ◽  
Yingjie Du ◽  
Yousif Alsaid ◽  
Dong Wu ◽  
Mutian Hua ◽  
...  

Ice accumulation causes various problems in our daily life for human society. The daunting challenges in ice prevention and removal call for novel efficient antiicing strategies. Recently, photothermal materials have gained attention for creating icephobic surfaces owing to their merits of energy conservation and environmental friendliness. However, it is always challenging to get an ideal photothermal material which is cheap, easily fabricating, and highly photothermally efficient. Here, we demonstrate a low-cost, high-efficiency superhydrophobic photothermal surface, uniquely based on inexpensive commonly seen candle soot. It consists of three components: candle soot, silica shell, and polydimethylsiloxane (PDMS) brushes. The candle soot provides hierarchical nano/microstructures and photothermal ability, the silica shell strengthens the hierarchical candle soot, and the grafted low-surface-energy PDMS brushes endow the surface with superhydrophobicity. Upon illumination under 1 sun, the surface temperature can increase by 53 °C, so that no ice can form at an environmental temperature as low as −50 °C and it can also rapidly melt the accumulated frost and ice in 300 s. The superhydrophobicity enables the melted water to slide away immediately, leaving a clean and dry surface. The surface can also self-clean, which further enhances its effectiveness by removing dust and other contaminants which absorb and scatter sunlight. In addition, after oxygen plasma treatment, the surface can restore superhydrophobicity with sunlight illumination. The presented icephobic surface shows great potential and broad impacts owing to its inexpensive component materials, simplicity, ecofriendliness, and high energy efficiency.


2007 ◽  
Vol 7 (12) ◽  
pp. 4456-4464 ◽  
Author(s):  
S. M. L. Silva ◽  
M. A. López-Manchado ◽  
M. Arroyo

The effect of different nanofillers and compatibilizers (maleic anhydride-grafted-polypropylene and maleic anhydride-grafted-ethylene propylene diene terpolymer rubber) on the morphology, mechanical, mechanodynamical and thermal characteristics of thermoplastic olefins based on polypropylene and ethylene propylene diene terpolymer rubber blends has been analysed. A better affinity with the matrix and a better dispersion of the nanoparticles is observed in rubber rich matrices. Organoclay, such as Cloisite C15A and Cloisite C20A, treated with a non-polar surfactant give rise to intercalated nanocomposites, and the lower the concentration of surfactant (C20A) the most noticeable increase in interlayer spacing and consequently better properties in the nanocomposites. The maleic anhydride-grafted-ethylene propylene diene terpolymer rubber is a better compatibilizer for organo-clay nanocomposites based on rubber rich matrices.


Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3475 ◽  
Author(s):  
Shijie Zhang ◽  
Zhenguo Gao ◽  
Di Lan ◽  
Qian Jia ◽  
Ning Liu ◽  
...  

Nitrated-pyrazole-based energetic compounds have attracted wide publicity in the field of energetic materials (EMs) due to their high heat of formation, high density, tailored thermal stability, and detonation performance. Many nitrated-pyrazole-based energetic compounds have been developed to meet the increasing demands of high power, low sensitivity, and eco-friendly environment, and they have good applications in explosives, propellants, and pyrotechnics. Continuous and growing efforts have been committed to promote the rapid development of nitrated-pyrazole-based EMs in the last decade, especially through large amounts of Chinese research. Some of the ultimate aims of nitrated-pyrazole-based materials are to develop potential candidates of castable explosives, explore novel insensitive high energy materials, search for low cost synthesis strategies, high efficiency, and green environmental protection, and further widen the applications of EMs. This review article aims to present the recent processes in the synthesis and physical and explosive performances of the nitrated-pyrazole-based Ems, including monopyrazoles with nitro, bispyrazoles with nitro, nitropyrazolo[4,3-c]pyrazoles, and their derivatives, and to comb the development trend of these compounds. This review intends to prompt fresh concepts for designing prominent high-performance nitropyrazole-based EMs.


2013 ◽  
Vol 594-595 ◽  
pp. 770-774 ◽  
Author(s):  
Husseinsyah Salmah ◽  
A. Siti Rohana ◽  
Hussin Kamarudin

Inorganic filler, calcium carbonate (CaCO3) was used as filler in the polypropylene (PP)/ ethylene propylene diene terpolymer (EPDM) composites. The composites were compatibilized with Maleic anhydride grafted polypropylene (MAPP) in order to improve the properties. The addition of CaCO3 at has increased the modulus of elasticity of composites but tensile strength and elongation at break of uncompatibilized composites decreased with increasing CaCO3. The result shows that the compatibilized composites higher tensile strength and Modulus of elasticity but lower elongation at break compared to uncompatibilized composites. At 10 wt% CaCO3 showed higher tensile strength of uncompatibiled and compatibilized composites. The morphology study from SEM analysis reveals that compatibilized composites show better interfacial adhesion between the filler and the matrix. The addition of MAPP has improved crystallinity of compatibilized composites.


2011 ◽  
Vol 55-57 ◽  
pp. 2210-2213
Author(s):  
Hu Ran Liu

Hydraulic motor with swinging bevel gear is a new kind of hydraulic motor. There are many advantages of it over other kind hydraulic motor. The decelerating ratio is big, moment work ratio is high, energy consuming is low, and decelerating function is good. Compared with other general liquid presses motor, this type of motor has the all new construction with the function, being applicable to the low turning the soon big turning the moment specially, high- efficiency realm. A principle for studying this kind of new motor with realize technique, include go together with to flow to convert the technique, adjust soon principle with method, the wheel gear theories matches the function with many cogwheels engaged, whole machine is excellent to turn the design, the kind machine manufactures experiment etc. with function on a trial basis to.The item's research for the country inside blank, spread to move to the host simplification, economize the energy, decline the low cost having got the important meaning.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaoqiang Yu ◽  
Qian Zhang ◽  
Xin Liu ◽  
Ning Xu ◽  
Lin Zhou

Solar interfacial evaporation, featured by high energy transfer efficiency, low cost, and environmental compatibility, has been widely regarded as a promising technology for solar desalination. However, the interplay between energy transfer and water transport in the same channels suggests that the tradeoff between high efficiency and long-term stability inherently exists in conventional photothermal nanomaterials. We summarize state-of-the-art research on various anti-salt clogging photothermal microstructures as long-term stable interfacial solar evaporators for solar desalination. The review starts with an overview of the current status and the fundamental limit of photothermal materials for solar desalination. Four representative strategies are analyzed in detail with the most recent experimental demonstrations, including fluid convection enhancement, surface wettability engineering, energy-mass-path decoupling, and surface chemistry engineering. Finally, this article focuses on the challenges in anti-salt clogging solar interfacial evaporators and potential point-of-use applications in the future.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Elsayed Elkhatib ◽  
Ahmed Mahdy ◽  
Fatma Sherif ◽  
Walaa Elshemy

There is increasing interest in using water treatment residuals (WTRs) for heavy metals removal from wastewater due to their low cost, availability, and high efficiency in removing various pollutants. In this study, novel water treatment residuals nanoparticles (nWTRs) were prepared using high energy ball milling and used for efficient removal of Cd(II) in single- and multi-ion systems. The WTR nanoparticles demonstrated high removal efficiency for Cd from aqueous solution as the adsorption capacities of nWTR were 17 and 10 times higher than those of bulk WTR in single- and multielement systems, respectively. Noticeably, Cd(II) adsorption was clearly suppressed in the multi-ion system as Cu and Pb form the most stable monohydroxo complexes. Fourier transmission infrared (FTIR) analyses suggested the participation of OH−, O-Al-O, FeOH, and FeOOH entities in the adsorption process. The stability of Cd-nWTR surface complexes is evident as less than 0. 2% of adsorbed Cd(ll) was released at the highest Cd(II) concentration load after 4 consecutive desorption cycles. Moreover, the real efficiency of nWTR for Cd(II) removal from wastewater samples studied was calculated to be 98.35%. These results highlight the potential of nWTR for heavy metals removal from wastewater.


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