Effect of the cross-linking process on the electrical resistivity and shape-memory behavior of cross-linked carbon black filled ethylene-octene copolymer

2010 ◽  
Vol 120 (4) ◽  
pp. 2138-2145 ◽  
Author(s):  
Hai Hong Le ◽  
Zulfiqar Ali ◽  
Mathias Uthardt ◽  
Sybill Ilisch ◽  
Hans-Joachim Radusch
Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1992 ◽  
Author(s):  
Alexey Kondyurin ◽  
Anastasia Eliseeva ◽  
Alexander Svistkov

A model of rubber with a cross-linked rubber layer on a carbon black filler has been proposed. The cross-links are the result of free radical reactions generated by carbon atoms with unpaired electrons at the edge of graphitic sheets in a carbon black filler. The experimental study of the cross-linking reactions in polyisoprene was done on a flat carbonized surface after ion beam implantation. The cross-linking process in the polyisoprene macromolecules between two particles was simulated. The model with a cross-linked rubber layer on a carbon filler as a “glassy layer” explains the mechanical properties of the rubber materials.


Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 807 ◽  
Author(s):  
Lin Xia ◽  
Han Gao ◽  
Weina Bi ◽  
Wenxin Fu ◽  
Guixue Qiu ◽  
...  

Shape memory composites of trans-1,4-polyisoprene (TPI) and low-density polyethylene (LDPE) with easily achievable transition temperatures were prepared by a simple physical blending method. Carbon black (CB) was introduced to improve the mechanical properties of the TPI/LDPE composites. The mechanical, cure, thermal and shape memory properties of the TPI/LDPE/CB composites were investigated in this study. In these composites, the crosslinked network generated in both the TPI and LDPE portions acted as a fixed domain, while the crystalline regions of the TPI and LDPE portions acted as a reversible domain in shape memory behavior. We found the mechanical properties of composites were promoted significantly with an increase of CB content, accompanied with the deterioration of shape memory properties of composites. When CB dosage was 5 parts per hundred of rubber composites (phr), best shape memory property of composites was obtained with a shape fixity ratio of 95.1% and a shape recovery ratio of 95.0%.


2010 ◽  
Vol 51 (3) ◽  
pp. 500-508 ◽  
Author(s):  
Hai Hong Le ◽  
Osayuki Osazuwa ◽  
Igor Kolesov ◽  
Sybill Ilisch ◽  
Hans-Joachim Radusch

2021 ◽  
Vol 903 ◽  
pp. 119-126
Author(s):  
Sintija Eglite ◽  
Astrida Berzina ◽  
Māris Knite

Ethylene-vinyl acetate (EVA) and highly structured carbon black (CB) composites are promising for self-regulating heating materials, especially, were flexibility is needed. Two types of EVA-CB composites were made. Firstly, non-cross-linked EVA-CB composite was made with different CB concentrations and secondly, cross-linked EVA-CB composite with dicumylperoxide (DCP) as the cross-linking agent. Different concentrations of DCP were used. Samples were tested in two ways – by heating them internally (by applying 5V voltage) and externally (by heating in universal heating oven). The electro-thermal properties (including PTC effect) were determined.


2021 ◽  
Vol 36 (1) ◽  
pp. 26-34
Author(s):  
Q. Ren ◽  
X. J. Wang ◽  
Y. Q. Zhao ◽  
L. Q. Xu ◽  
H. W. Yu ◽  
...  

Abstract Shape memory polymers (SMPs) are developed by blending and cross-linking polymers which include crystalline domains and cross-linked networks. In this paper, we describe the morphology, thermal and shape memory behavior of methyl vinyl silicone rubber (MVMQ)/olefin block copolymer (OBC) blends prepared by a melt-blending and chemical cross-linking method. MVMQ without crystalline domains could not hold its temporary shape. After introducing the OBC, the obtained blends exhibited excellent dual shape memory properties. The cross-linking networks of MVMQ acted as reversible domains, while crystalline regions of OBC worked as fixed domains. When the blending ratio of MVMQ/OBC was 50/ 50, the blend had both a high shape fixity ratio and shape recovery ratio.


2017 ◽  
Vol 90 (4) ◽  
pp. 585-610 ◽  
Author(s):  
Padmanabhan Ramachandran ◽  
Joyeeta Dutta ◽  
Tuhin Chatterjee ◽  
Golok B. Nando ◽  
Kinsuk Naskar

ABSTRACT This article demonstrates the influence of different cross-linking methods of the ethylene octene copolymer (EOC)–polydimethylsiloxane (PDMS) rubber blends. From rheology analysis, it is understood that the EOC with a high co-monomer content has better radiation cross-linkability as compared with the EOC with a low co-monomer content. Also, from the curing study using an oscillating die rheometer, it was found that as the octene content increases, the cross-linking efficiency of the peroxide to cross-link that particular EOC decreases. The tensile strength of the EOC2:PDMS blend with a high co-monomer content was drastically improved by 39% on irradiation with a dosage of 50 kGy, whereas for the EOC:PDMS blend with a low co-monomer content, the tensile strength was drastically improved by 60% on peroxide cross-linking. It is inferred that both the peroxide and radiation cross-linked blends show higher creep resistance compared with the neat blends. From the thermal studies, it was found that through blending and subsequent radiation cross-linking, the maximum degradation temperature of the high-octene-content EOC was increased from 480.5 °C to 509.1 °C. The cross-linked blends show higher-volume resistivity as compared with the un-cross-linked counterparts.


2011 ◽  
Vol 22 (18) ◽  
pp. 2147-2154 ◽  
Author(s):  
Dawei Zhang ◽  
Yanju Liu ◽  
Kai Yu ◽  
Jinsong Leng

The influence of cross-linking agent content on thermomechanical properties and shape recovery behavior of thermoset styrene shape memory polymer (SMP) was investigated in this article. The SMP was polymerized by free radical reaction, with styrene and butyl acrylate as comonomers and divinylbenzene as the cross-linking agent. When the cross-linking agent content is increased from 1 to 4 wt%, the storage modulus and the glass transition temperature ( Tg) of the SMP increased correspondingly. During the glass transition, while the value of damping peak decreased as a result of the addition of the cross-linking agent, the peak width increased, and the main relaxation activation energy increased by 48.6%. When the active temperature was higher than or equal to Tg, the SMP samples containing different weight percentages of the cross-linking agent could recover their original shape. At or above Tg, SMP with varied fractions of cross-linking agent could completely recover its original shape; the recovery rate of SMP increased with the increase in the contents of the cross-linking agent. Below Tg, SMP could not recover its original shape, but the recovery angle increased as the contents of cross-linking agent increased. These results were attributed to the increase of cross-linking densities as a result of the addition of cross-linking agent.


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