Polymers
·
2019
·Vol. 11
·期 10
·1599
·
IF 3.164
Xiaoming Qi,Wentong Yang,Laiming Yu,Wenjun Wang,Haohao Lu,Yanglong Wu,Shanwen Zhu,Yaofeng Zhu,Xiangdong Liu,Yubing Dong,Yaqin Fu
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.Keywords:shape memory polymer fiber;two-way shape memory effect;melt spinning;UV curing
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yutong Guo,Yujie Chen,Qili Yu,Hezhou Liu,Hua Li,Yinxian Yu
Two-way shape memory polymers (2WSMP) are highly desired for artificial muscles, soft actuators and sensors, while the stress-free 2WSMP greatly expands the practical potential of shape memory polymers. However, traditional 2WSMP cannot show high strength or good mechanical properties, which limited its practical application. It is important to create a new reversible polymer system in order to obtain more intricate movements, precise control and great mechanical properties. Herein, a two-way shape memory polyurethane was created using a new molecular strategy, which shows great properties, i.e., 2342% super stretch strain, 591 MPa true tensile strength, 708.04 J/kg of energy density, and 667.96 W/kg of power density. In addition, the 2WSMP could achieve a maximum 24.53% reversible transformation under 1 MPa stress, and 13.7% two-way shape change without external stress, respectively. In this polyurethane, the great mechanical properties and stress-free two-way shape memory effect are caused by the elastic polybutadiene (PB) segments, which acts as a “molecular spring.” Furthermore, this 2WSMP could simulate reversible muscle-like motion, and be employed in ligaments. Consequently, this polyurethane offers a fresh design concept for stress-free two-way performance memory polymers and has a wide range of potential applications in the field of artificial muscles, soft actuators and ligaments.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Smart Materials and Structures
·
2025
·Vol. 34
·期 9
·095019
·
IF 3.8
Shaojun Chen,Yonghang Zhang,Youhan Zeng,Yujie Deng,Haitao Zhuo,Haiqiang Zhong,Huaiping Zhang
Shape memory polymers (SMPs) are one of the most typical intelligent materials. However, the precise regulation of the shape memory effect (SME) remains a critical challenge in the field. This study introduces a simple strategy for regulating the SME, employing crystalline thermoplastic polyurethane (CTPU) as the raw material and utilizing isophorone diisocyanate (IPDI) trimer to regulate both one-way SME (1W-SME) and two-way SME (2W-SME). Results showed that incorporation of IPDI-trimer induced a cross-linked network within CTPU. The tensile strength at break reached a maximum of 27.4 MPa, and the elongation at break remained relatively high (2484%) when the IPDI-trimer content was below 10wt%. The resulting cross-linked CTPU exhibited exceptional one-way shape memory performance, achieving a 99.9% recovery rate and 96.4% fixation rate. Notably, switchable 2W-SME emerged when IPDI-trimer concentrations exceeded 11wt%. This dual SME functionality, coupled with a 54.3% actuation magnitude, signified a significant advancement in SMPs capabilities. Systematic analysis reveals that shape memory activation originates from the synergistic effects of oriented crystalline domain melting and energy release within the cross-linked network under thermal stimuli. The precise control of 1W-SME and 2W-SME demonstrated in this study fundamentally arises from regulated crystallinity and cross-linking degree of CTPU. Owing to these enhanced integrated properties, these materials show great promise for diverse applications, particularly in smart sensors and intelligent robotics.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）