Facile fabrication of shape memory composites from naturalEucommiarubber and high density polyethylene

2017 ◽  
Vol 66 (5) ◽  
pp. 653-658 ◽  
Author(s):  
Lin Xia ◽  
Yan Wang ◽  
Na Lu ◽  
Zhenxiang Xin
Keyword(s):  
Shape Memory ◽  
High Density Polyethylene ◽  
High Density ◽  
Shape Memory Composites ◽  
Facile Fabrication

Analytical and experimental study of shape memory alloy reinforcement on the performance of butt-fusion welded joints in high-density polyethylene pipe

2020 ◽  
Vol 31 (17) ◽  
pp. 2029-2043
Author(s):  
Eunsoo Choi ◽  
Alireza Ostadrahimi ◽  
Heejung Youn
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
High Density Polyethylene ◽  
Welded Joint ◽  
High Density ◽  
Shape Memory Alloy Wire ◽  
Alloy Wire ◽  
Polyethylene Pipe ◽  
Polyethylene Pipes ◽  
Fusion Welded Joints

In this article, a shape memory alloy wire is employed as confinement to enhance the flexural rigidity of the butt-fusion welded joints in the high-density polyethylene pipes. To this end, analytical and experimental studies are considered, when the shape memory alloy wire is wrapped around a butt-fusion joint and an internal pressure is applied to the high-density polyethylene pipe. To investigate the efficiency of shape memory alloy wire jacket on the performance of butt-fusion welded joint in high-density polyethylene pipe, two cases of perfect butt-fusion joint and imperfect butt-fusion joint are tested. The influence of the number of shape memory alloy wire jacket on the high-density polyethylene pipe joints as well as the effect of different flexural rigidities of the wire and high-density polyethylene pipe, and different diameters are evaluated. The deformation is measured using linear voltage displacement transducer and digital image correlation analysis at different location of the pipe length. In addition, radial strain of the pipes due to bulging is measured by electronic resistance strain gauges. Results show that the shape memory alloy wire jacket has a significant effect (33%) on enhancing imperfect butt-fusion welded joint of high-density polyethylene pipes.

scholarly journals Facile Fabrication of Eucommia Rubber Composites with High Shape Memory Performance

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3479
Author(s):  
Lin Xia ◽  
Jiafeng Meng ◽  
Yuan Ma ◽  
Ping Zhao
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Memory Performance ◽  
Analytical Techniques ◽  
Cross Linking ◽  
Rubber Composites ◽  
Restoring Force ◽  
Shape Memory Composites ◽  
Facile Fabrication ◽  
Properties Of Materials

We processed a series of shape memory Eucommia rubber (ER) composites with both carbon–carbon and ionic cross-linking networks via a chemical cross-linking method. The influence of the carbon–carbon cross-linking and ion cross-linking degree of ER composites on curing, mechanical, thermal, and shape memory properties were studied by DSC, DMA, and other analytical techniques. Dicumyl peroxide (DCP) and zinc dimethacrylate (ZDMA) played a key role in preparing ER composites with a double cross-linking structure, where DCP initiated polymerization of ZDMA, and grafted ZDMA onto polymer molecular chains and cross-linked rubber molecular chains. Meanwhile, ZDMA combined with rubber macromolecules to build ionic cross-linking bonds in composites under the action of DCP and reinforced the ER composites. The result showed that the coexistence of these two cross-linking networks provide a sufficient restoring force for deformation of shape memory composites. The addition of ZDMA not only improved the mechanical properties of materials, but also significantly enhanced shape memory performance of composites. In particular, Eucommia rubber composites exhibited outstanding mechanical properties and shape memory performance when DCP content was 0.2 phr.

Composition and Surface Topography Effects on Apatite-Forming Ability of Ceramic-Polymer Composites

2003 ◽  
Vol 774 ◽  
Author(s):  
Susan M. Rea ◽  
Serena M. Best ◽  
William Bonfield
Keyword(s):  
Surface Topography ◽  
High Density Polyethylene ◽  
High Density ◽  
Apatite Layer ◽  
Biologically Active ◽  
Human Blood Plasma ◽  
Apatite Formation ◽  
Polyethylene Matrix ◽  
Composite Surface ◽  
X Ray

AbstractHAPEXTM (40 vol% hydroxyapatite in a high-density polyethylene matrix) and AWPEX (40 vol% apatite-wollastonite glass ceramic in a high density polyethylene matrix) are composites designed to provide bioactivity and to match the mechanical properties of human cortical bone. HAPEXTM has had clinical success in middle ear and orbital implants, and there is great potential for further orthopaedic applications of these materials. However, more detailed in vitro investigations must be performed to better understand the biological interactions of the composites and so the bioactivity of each material was assessed in this study. Specifically, the effects of controlled surface topography and ceramic filler composition on apatite layer formation in acellular simulated body fluid (SBF) with ion concentration similar to those of human blood plasma were examined. Samples were prepared as 1 cm × 1 cm × 1 mm tiles with polished, roughened, or parallel-grooved surface finishes, and were incubated in 20 ml of SBF at 36.5 °C for 1, 3, 7, or 14 days. The formation of a biologically active apatite layer on the composite surface after immersion was demonstrated by thin-film x-ray diffraction (TF-XRD), environmental scanning electron microscopy (ESEM) imaging and energy dispersive x-ray (EDX) analysis. Variations in sample weight and solution pH over the period of incubation were also recorded. Significant differences were found between the two materials tested, with greater bioactivity in AWPEX than HAPEXTM overall. Results also indicate that within each material the surface topography is highly important, with rougher samples correlated to earlier apatite formation.

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