HEAT-TRIGGERED SHAPE MEMORY EFFECT OF PEROXIDE CROSS-LINKED ETHYLENE–METHACRYLIC ACID COPOLYMER/NITRILE–BUTADIENE RUBBER THERMOPLASTIC VULCANIZATES WITH SEA-ISLAND STRUCTURE

2021 ◽  
Author(s):  
Yingtao Sun ◽  
Jiahao Li ◽  
Kerui Liao ◽  
Jing Hua ◽  
Zhaobo Wang
Keyword(s):  
Shape Memory ◽  
Methacrylic Acid ◽  
Shape Recovery ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
Nitrile Butadiene Rubber ◽  
Acid Copolymer ◽  
Thermoplastic Vulcanizates ◽  
Switching Temperature ◽  
Shape Fixity

ABSTRACT Designing shape memory polymers (SMPs) based on thermoplastic vulcanizates (TPVs) is an essential research topic. An efficient SMP is designed with typical sea-island structured ethylene–methacrylic acid copolymer/nitrile–butadiene rubber (EMA/NBR) TPVs in which the heat-control switched phase performed by the EMA phase is related to the shape fixity ability. The results show that the heat-triggered SMPs exhibit surprising shape memory properties (shape fixity >95%, shape recovery >95%, and fast recovery speed <30 s at the switching temperature of 95 °C). Through X-ray diffraction characterization, it is seen that the shape fixity of TPVs is achieved mainly through ethylene crystallization. The switching temperature is largely determined by the melting temperature (98 °C) obtained by differential scanning calorimetery.

Dynamically vulcanized ethylene-methacrylic acid copolymer/nitrile butadiene rubber blends reinforced by zinc dimethacrylate

2019 ◽  
pp. 089270571986648
Author(s):  
Kerui Liao ◽  
Feifei Liu ◽  
Zhaobo Wang
Keyword(s):  
Mechanical Properties ◽  
Methacrylic Acid ◽  
Residual Deformation ◽  
Mullins Effect ◽  
Butadiene Rubber ◽  
Dynamic Vulcanization ◽  
Rubber Blends ◽  
Nitrile Butadiene Rubber ◽  
Acid Copolymer ◽  
Etched Surface

Thermoplastic vulcanizates (TPVs) based on ethylene-methacrylic acid (EMA) copolymer/nitrile butadiene rubber (NBR) blends were prepared by dynamic vulcanization where the NBR phase was reinforced by zinc dimethacrylate (ZDMA). The effect of ZDMA dosage on the mechanical properties, Mullins effect, and morphology of the TPVs was investigated systematically. Experimental results indicated that the mechanical properties of EMA/NBR TPVs were enhanced remarkably with the incorporation of ZDMA. Morphology study showed that the NBR particles with diameters of about 1–5 μm were dispersed evenly in the etched surface of EMA/NBR/ZDMA TPV. The Mullins effect could be observed in the stress–strain curves of EMA/NBR TPV and EMA/NBR/ZDMA TPV during the uniaxial loading–unloading cycles. Compared with those of EMA/NBR TPV, EMA/NBR/ZDMA TPV had the higher stress, residual deformation, and internal friction loss.

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 Unique microstructure of an oil resistant nitrile butadiene rubber/polypropylene dynamically vulcanized thermoplastic elastomer

RSC Advances ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 5451-5458 ◽  
Author(s):  
Nanying Ning ◽  
Xiangyan Li ◽  
Hongchi Tian ◽  
Yueqing Hua ◽  
Hongli Zuo ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Thermoplastic Elastomer ◽  
Butadiene Rubber ◽  
Nitrile Butadiene Rubber ◽  
Thermoplastic Vulcanizates

This paper reports on the microstructure, morphological evolution and the properties of oil resistant nitrile butadiene rubber (NBR)/polypropylene (PP) thermoplastic vulcanizates (TPVs) prepared by dynamical vulcanization (DV).

Characristics of Shape Memory Composites Combined with Shape Memory Alloy and Shape Memory Polymer

2013 ◽  
Vol 705 ◽  
pp. 169-172
Author(s):  
Xue Feng ◽  
Li Min Zhao ◽  
Xu Jun Mi
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Young Modulus ◽  
Thermomechanical Properties ◽  
The Matrix ◽  
Shape Memory Composites ◽  
Shape Fixity

In order to develop high functionality of shape memory materials, the shape memory composites combined with TiNi wire and shape memory epoxy were prepared, and the mechanical and thermomechanical properties were studied. The results showed the addition of TiNi wire increased the Young modulus and breaking strength both at room temperature and at elevated temperature. The composites maintained the rates of shape fixity and shape recovery close to 100%. The maximum recovery stress increased with increasing TiNi wire volume fraction, and obtained almost 3 times of the matrix by adding 1vol% TiNi wire.

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