Issues for consideration in the design of shape memory polymer systems

2008 ◽  
Author(s):  
D. Pandit ◽  
A. P. Deshpande ◽  
S. M. Sivakumar ◽  
Srinivasan M. Sivakumar ◽  
Vidyashankar Buravalla ◽  
...  
Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4254
Author(s):  
Paulina A. Quiñonez ◽  
Leticia Ugarte-Sanchez ◽  
Diego Bermudez ◽  
Paulina Chinolla ◽  
Rhyan Dueck ◽  
...  

The work presented here describes a paradigm for the design of materials for additive manufacturing platforms based on taking advantage of unique physical properties imparted upon the material by the fabrication process. We sought to further investigate past work with binary shape memory polymer blends, which indicated that phase texturization caused by the fused filament fabrication (FFF) process enhanced shape memory properties. In this work, two multi-constituent shape memory polymer systems were developed where the miscibility parameter was the guide in material selection. A comparison with injection molded specimens was also carried out to further investigate the ability of the FFF process to enable enhanced shape memory characteristics as compared to other manufacturing methods. It was found that blend combinations with more closely matching miscibility parameters were more apt at yielding reliable shape memory polymer systems. However, when miscibility parameters differed, a pathway towards the creation of shape memory polymer systems capable of maintaining more than one temporary shape at a time was potentially realized. Additional aspects related to impact modifying of rigid thermoplastics as well as thermomechanical processing on induced crystallinity are also explored. Overall, this work serves as another example in the advancement of additive manufacturing via materials development.


2016 ◽  
Vol 37 (22) ◽  
pp. 1837-1843 ◽  
Author(s):  
Syamal S. Tallury ◽  
Behnam Pourdeyhimi ◽  
Melissa A. Pasquinelli ◽  
Richard J. Spontak

2016 ◽  
Vol 478 ◽  
pp. 334-343 ◽  
Author(s):  
Sayyeda M. Hasan ◽  
Alexandra D. Easley ◽  
Mary Beth Browning Monroe ◽  
Duncan J. Maitland

Author(s):  
Xin Wu ◽  
Leonard Dauerman ◽  
Song Zhang ◽  
Xiao Qiao ◽  
Jose Mabesa

In recent years shape memory effect in polymer systems has drawn great attention for its potential applications for MEMS and medical devices. In this paper, the visco-elastic and plastic behavior and strain recovery characteristics of a thermoplastic have been studied extensively. Creep deformation by compression was performed under load or displacement control mode, and under monotonic or cyclic loading. The strain recovery ratio of the shape memory polymer is found to be strongly affected by the deformation temperature, isothermal holding temperature and time, amount of forward strain and relaxation time, and the number of cycles of strain/recovery. The creep behavior of the material is modeled.


2008 ◽  
Vol 47-50 ◽  
pp. 258-261 ◽  
Author(s):  
Hai Bao Lv ◽  
Yan Ju Liu ◽  
Dong Xing Zhang ◽  
Jin Song Leng ◽  
Shan Yi Du

Recently, there is interest in triggering shape recovery of shape-memory polymers(SMPs) by novel non-external heating. In this paper, many hard works have been carried out to make SMP induced by solution. The main challenge in the development of such polymer systems is the conversion of solution-induced effects at the molecular level to macroscopic movement of working pieces. This paper presents a systematic study on the effects of solution on the glass transition temperature (Tg). The results reveal that the hydrogen bonding of shape memory polymer (SMP) was aroused by the absorbed solution that significantly reduces Tg of polymer. The mechanism behind it is solution firstly intenerates polymeric materials till the Tg of polymer lowered down to the temperature of ambient, then hydrogen bonding interaction improves the flexibility of polymeric macro-molecular chains. Thus, the shape memory effect (SME) can undergo solution-driven shape recovery. In addition, it provides a new approach that the SMP can be induced by applying non-energy stimulus. The Dynamic Mechanical Analyzer (DMA) results reveal that the modulus of polymer was softened gradually with immersion time increasing. The experimental result is approximate to the theory.


2013 ◽  
Vol 46 (22) ◽  
pp. 8905-8916 ◽  
Author(s):  
Keith Hearon ◽  
Celine J. Besset ◽  
Alexander T. Lonnecker ◽  
Taylor Ware ◽  
Walter E. Voit ◽  
...  

2021 ◽  
pp. 2102473
Author(s):  
Wenjun Peng ◽  
Guogao Zhang ◽  
Qian Zhao ◽  
Tao Xie

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1275 ◽  
Author(s):  
Guido Ehrmann ◽  
Andrea Ehrmann

Poly(lactic acid) is not only one of the most often used materials for 3D printing via fused deposition modeling (FDM), but also a shape-memory polymer. This means that objects printed from PLA can, to a certain extent, be deformed and regenerate their original shape automatically when they are heated to a moderate temperature of about 60–100 °C. It is important to note that pure PLA cannot restore broken bonds, so that it is necessary to find structures which can take up large forces by deformation without full breaks. Here we report on the continuation of previous tests on 3D-printed cubes with different infill patterns and degrees, now investigating the influence of the orientation of the applied pressure on the recovery properties. We find that for the applied gyroid pattern, indentation on the front parallel to the layers gives the worst recovery due to nearly full layer separation, while indentation on the front perpendicular to the layers or diagonal gives significantly better results. Pressing from the top, either diagonal or parallel to an edge, interestingly leads to a different residual strain than pressing from front, with indentation on top always firstly leading to an expansion towards the indenter after the first few quasi-static load tests. To quantitatively evaluate these results, new measures are suggested which could be adopted by other groups working on shape-memory polymers.


RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19616-19622
Author(s):  
Wenbing Li ◽  
Junhao Liu ◽  
Wanting Wei ◽  
Kun Qian

Shape memory polymers can provide excellent bonding property because of their shape memory effects. This paper proposes an adhesive unit that is capable of repeatable smart adhesion and exhibits reversible adhesion under heating.


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