Two-way multi-shape memory properties of peroxide crosslinked ethylene vinyl-acetate copolymer (EVA)/polycaprolactone (PCL) blends

2018 ◽  
Vol 29 (7) ◽  
pp. 2010-2024 ◽  
Author(s):  
Jin-Lin Han ◽  
Sun-Mou Lai ◽  
Yu Ting Chiu
Keyword(s):  
Shape Memory ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Shape Memory Properties ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

scholarly journals Design of Ethylene-Vinyl Acetate Copolymer Fiber with Two-Way Shape Memory Effect

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1599 ◽  
Author(s):  
Xiaoming Qi ◽  
Wentong Yang ◽  
Laiming Yu ◽  
Wenjun Wang ◽  
Haohao Lu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Vinyl Acetate ◽  
Memory Effect ◽  
Crosslink Density ◽  
Melt Spinning ◽  
Uv Curing ◽  
Ethylene Vinyl Acetate ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

One-dimensional shape memory polymer fibers (SMPFs) have obvious advantages in mechanical properties, dispersion properties, and weavability. In this work, a method for fabricating semi-crystallization ethylene-vinyl acetate copolymer (EVA) fiber with two-way shape memory effect by melt spinning and ultraviolet (UV) curing was developed. Here, the effect of crosslink density on its performance was systematically analyzed by gel fraction measurement, tensile tests, DSC, and TMA analysis. The results showed that the crosslink density and shape memory properties of EVA fiber could be facilely adjusted by controlling UV curing time. The resulting EVA fiber with cylindrical structure had a diameter of 261.86 ± 13.07 μm, and its mechanical strength and elongation at break were 64.46 MPa and 114.33%, respectively. The critical impact of the crosslink density and applied constant stress on the two-way shape memory effect were analyzed. Moreover, the single EVA fiber could lift more than 143 times its own weight and achieve 9% reversible actuation strain. The reversible actuation capability was significantly enhanced by a simple winding design of the single EVA fiber, which provided great potential applications in smart textiles, flexible actuators, and artificial muscles.

scholarly journals Design of ethylene-vinyl acetate copolymer fiber with two-way shape memory effect

2019 ◽  
Author(s):  
Xiaoming Qi ◽  
Wentong Yang ◽  
Laiming Yu ◽  
Wenjun Wang ◽  
Haohao Lu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Vinyl Acetate ◽  
Memory Effect ◽  
Crosslink Density ◽  
Melt Spinning ◽  
Uv Curing ◽  
Ethylene Vinyl Acetate ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

One-dimensional shape memory polymer fibers (SMPFs) have obvious advantages in mechanical properties, dispersion properties and weavability. In this work, a method for fabricating semi-crystallization ethylene-vinyl acetate copolymer (EVA) fiber with two-way shape memory effect by melt spinning and ultraviolet (UV) curing was developed. Here, the effect of crosslink density on its performance was systematically analyzed by gel fraction measurement, tensile tests, DSC and TMA analysis. The results showed that the crosslink density and shape memory properties of EVA fiber could be facilely adjusted by controlling UV curing time. The resulting EVA fiber with cylindrical structure had a diameter of 247.13 ± 10.07 μm, and its mechanical strength and elongation at break were 64.46 MPa and 114.33%, respectively. The critical impact of the crosslink density and applied constant stress on the two-way shape memory effect were analyzed. Moreover, the single EVA fiber could lift more than 143 times its own weight and achieve 9% reversible actuation strain. The reversible actuation capability was significantly enhanced by a simple winding design of the single EVA fiber, which provided great potential applications in smart textiles, flexible actuators and artificial muscles.

A novel heat-triggered shape-memory polymer based on ethylene–vinyl acetate copolymer/nitrile–butadiene rubber thermoplastic vulcanizates

2019 ◽  
Vol 33 (9) ◽  
pp. 1217-1233 ◽  
Author(s):  
Libin Wang ◽  
Kesi Xiong ◽  
Zhaobo Wang
Keyword(s):  
Shape Memory ◽  
Vinyl Acetate ◽  
Shape Memory Polymer ◽  
Weight Ratio ◽  
Ethylene Vinyl Acetate ◽  
Butadiene Rubber ◽  
Nitrile Butadiene Rubber ◽  
Thermoplastic Vulcanizates ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

Achieving considerable shape-memory effects is a challenge for typical sea-island structured polymer blends. In this article, we successfully fabricated a novel heat-triggered shape-memory polymer (HSMP) based on ethylene–vinyl acetate copolymer/nitrile–butadiene rubber (EVA/NBR) thermoplastic vulcanizates (TPVs) via dynamic vulcanization. The influence of deformation temperature ( Td), recovery temperature ( Tr), and recovery time on the shape-memory behavior of the EVA/NBR (weight ratio = 80/20) TPV was investigated systematically. The shape-memory result of the EVA/NBR (weight ratio = 80/20) TPV demonstrated that when the Td was close to the melting temperature ( Tm) of the EVA phase (76°C), the TPV could obtain a good shape fixity ratio (>95%) and an excellent shape recovery ratio (>95%) at 100% stretch ratio. A shape-memory mechanism was proposed for this HSMP. The dynamic mechanical analysis results under temperature sweep mode showed that with increasing EVA content in TPVs, the tan δ decreased, while the storage modulus increased. The morphology observation showed that the cross-linked NBR particles were dispersed evenly in the etched surface of EVA/NBR TPV with an average diameter of approximately 2–6 μm. The longitudinal stretching surface of the EVA/NBR TPV exhibited the banding-like texture microstructure during the stretching process.

scholarly journals Indicator Layers Based on Ethylene-Vinyl Acetate Copolymer (EVA) and Dicyanovinyl Azobenzene Dyes for Fast and Selective Evaluation of Vaporous Biogenic Amines

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4361
Author(s):  
Tinkara Mastnak ◽  
Aleksandra Lobnik ◽  
Gerhard Mohr ◽  
Matjaž Finšgar
Keyword(s):  
Biogenic Amines ◽  
Vinyl Acetate ◽  
Colour Change ◽  
Ethylene Vinyl Acetate ◽  
Yellow Orange ◽  
Colour Changes ◽  
Limit Sensitivity ◽  
Linear Concentration Range ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

The article presents naked-eye methods for fast, sensitive, and selective detection of isopentylamine and cadaverine vapours based on 4-N,N-dioctylamino-4′-dicyanovinylazobenzene (CR-528) and 4-N,N-dioctylamino-2′-nitro-4′-dicyanovinylazobenzene (CR-555) dyes immobilized in ethylene-vinyl acetate copolymer (EVA). The reaction of CR-528/EVA and CR-555/EVA indicator layers with isopentylamine vapours caused a vivid colour change from pink/purple to yellow/orange-yellow. Additionally, CR-555/EVA showed colour changes upon exposure to cadaverine. The colour changes were analysed by ultraviolet–visible (UV/VIS) molecular absorption spectroscopy for amine quantification, and the method was partially validated for the detection limit, sensitivity, and linear concentration range. The lowest detection limits were reached with CR-555/EVA indicator layers (0.41 ppm for isopentylamine and 1.80 ppm for cadaverine). The indicator layers based on EVA and dicyanovinyl azobenzene dyes complement the existing library of colorimetric probes for the detection of biogenic amines and show great potential for food quality control.

Sign in / Sign up

Export Citation Format

Share Document