Tailoring the impact behavior of polyamide 6 ternary blends via a hierarchical core–shell structure in situ formed in melt mixing

RSC Advances ◽  
2015 ◽  
Vol 5 (19) ◽  
pp. 14592-14602 ◽  
Author(s):  
Rui Dou ◽  
Chao Shen ◽  
Bo Yin ◽  
Ming-bo Yang ◽  
Bang-hu Xie

The hierarchical core–shell structure in PA6/HDPE-g-MA/EPDM ternary blend was firstly formed using simple melt mixing. A super toughness PA6 ternary blends with HDPE-g-MA multi-core structure was obtained.

2019 ◽  
Vol 39 (5) ◽  
pp. 407-414 ◽  
Author(s):  
Xueqiang Zhang ◽  
Jun Zhang

AbstractAcrylonitrile-styrene-acrylic (ASA) terpolymer has a typical core-shell structure with poly(butyl acrylate) (PBA) as the soft core and styrene-acrylonitrile (SAN) copolymer as the hard shell. The impact behavior of poly(vinyl chloride) (PVC)/ASA binary blends with various ASA terpolymer contents was systematically investigated at three different temperatures (23°C, 0°C, and –30°C). With the addition of 30 phr ASA terpolymer, the impact strength of the blends increased by almost 45 times at 23°C and 29 times at 0°C compared with the neat PVC, respectively. Herein, ASA terpolymer particles were related to each other to form a percolation group and the stress field around the ASA particles was connected with each other, thereby more effectively served as the stress concentrators, exhibiting the highest toughening efficiency. In addition, the significantly improved toughness could also be attributed to the special core-shell structure of ASA terpolymer, as well as, a good miscibility between the PVC matrix and the SAN shell of the ASA terpolymer. However, the decreasing temperature limited the flexibility of the PBA chain, resulting in the insignificant role of ASA terpolymer in toughening PVC at –30°C. Moreover, the improvement in the toughness of the blends did not sacrifice its heat distortion temperature.


Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1201
Author(s):  
Xinghua Ji ◽  
Cheng Zhang ◽  
Shufeng Li

SiCp reinforced aluminium matrix composites (AMCs), which are widely used in the aerospace, automotive, and electronic packaging fields along with others, are usually prepared by ex situ techniques. However, interfacial contamination and poor wettability of the ex situ techniques make further improvement in their comprehensive performance difficult. In this paper, SiCp reinforced AMCs with theoretical volume fractions of 15, 20, and 30% are prepared by powder metallurgy and in situ reaction via an Al-Si-C system. Moreover, a combined method of external addition and an in situ method is used to investigate the synergistic effect of ex situ and in situ SiCp on AMCs. SiC particles can be formed by an indirect reaction: 4Al + 3C → Al4C3 and Al4C3 + 3Si → 3SiC + 4Al. This reaction is mainly through the diffusion of Si, in which Si diffuses around Al4C3 and then reacts with Al4C3 to form SiCp. The in situ SiC particles have a smooth boundary, and the particle size is approximately 1–3 μm. A core-shell structure having good bonding with an aluminium matrix was generated, which consists of an ex situ SiC core and an in situ SiC shell with a thickness of 1–5 μm. The yield strength and ultimate tensile strength of in situ SiCp reinforced AMCs can be significantly increased with a constant ductility by adding 5% ex situ SiCp for Al-28Si-7C. The graphite particle size has a significant effect on the properties of the alloy. A criterion to determine whether Al4C3 is a complete reaction is achieved, and the forming mechanism of the core-shell structure is analysed.


2011 ◽  
Vol 71-78 ◽  
pp. 928-931
Author(s):  
Jin Liang Wu ◽  
Yong Xing Zhang ◽  
Chun Sun Zhang

Nowadays, there are dominantly two ways of producing modified emulsified asphalt ,one of which is to emulsify modified asphalt, the other to modify asphalt emulsion. But they have the same defect that modifier cannot be evenly mixed with asphalt emulsion, which has side effect on the performance of modified emulsified asphalt. The emulsified asphalt and modifier have different traits in structure and property. In order to make the modifier disperse in asphalt emulsion evenly to improve the performance of modified emulsified asphalt, a tentative idea is brought forward: we shall utilize in-situ polymerization and core-shell structure to enhance feature of emulsified asphalt. Core-shell structure is a method of synthesizing composite material, which can assist to achieve sound effect of the two kinds of materials. The point to emphasize is, in this paper, the introduction and feasibility of the method, its specialty against current mainly methods, the difficulties encountered in practice as well as its promising prospect and the anticipated target to achieve will all be illustrated.


2019 ◽  
Vol 35 (14) ◽  
pp. 1727-1734
Author(s):  
Lisheng Zhong ◽  
Haiqiang Bai ◽  
Junzhe Wei ◽  
Jianlei Zhu ◽  
Jianhong Peng ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (120) ◽  
pp. 98904-98909 ◽  
Author(s):  
Jiangru Zhang ◽  
Guicun Qi ◽  
Xiang Wang ◽  
Binghai Li ◽  
Zhihai Song ◽  
...  

For the first time, an ultrafine conductive particle with core–shell structure, acrylonitrile-butadiene elastomeric nanoparticle (NBR-ENP) coated with polypyrrole (PPy), was prepared by in situ oxidative polymerization.


RSC Advances ◽  
2017 ◽  
Vol 7 (71) ◽  
pp. 44626-44631 ◽  
Author(s):  
Xianglin Zhu ◽  
Peng Wang ◽  
Qianqian Zhang ◽  
Zeyan Wang ◽  
Yuanyuan Liu ◽  
...  

CdS–MoS2 photoelectrode with a double layers core shell structure was prepared on Mo substrate through using a simple electrodeposition and– in situ sulfurization method on Mo substrate.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1446
Author(s):  
Andrey A. Saraev ◽  
Svetlana A. Yashnik ◽  
Evgeny Yu. Gerasimov ◽  
Anna M. Kremneva ◽  
Zakhar S. Vinokurov ◽  
...  

In this study, 3%Pd/Al2O3, 3%Pt/Al2O3 and bimetallic (1%Pd + 2%Pt)/Al2O3 catalysts were examined in the total oxidation of methane in a temperature range of 150–400 °C. The evolution of the active component under the reaction conditions was studied by transmission electron microscopy and in situ extended X-ray absorption fine structure (EXAFS) spectroscopy. It was found that the platinum and bimetallic palladium-platinum catalysts are more stable against sintering than the palladium catalysts. For all the catalysts, the active component forms a “core-shell” structure in which the metallic core is covered by an oxide shell. The “core-shell” structure for the platinum and bimetallic palladium-platinum catalysts is stable in the temperature range of 150–400 °C. However, in the case of the palladium catalysts the metallic core undergoes the reversible oxidation at temperatures above 300 °C and reduced to the metallic state with the decrease in the reaction temperature. The scheme of the active component evolution during the oxidation of methane is proposed and discussed.


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