Shape Memory Polymers: Applications and Associated Manufacturing Techniques

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Applications".

Deadline for manuscript submissions: closed (31 January 2022) | Viewed by 11335

Special Issue Editor


E-Mail Website
Guest Editor
IRC in Polymer Science and Technology, School of Engineering, Faculty of Engineering and Informatics, University of Bradford, Bradford BD7 1DP, UK
Interests: polymers; mechanical properties; constitutive model; finite element modelling; shape memory polymer
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Shape memory polymers (SMPs) have been developed over the last few decades and have begun to find practical applications. While many of the applications are in the biomedical area, there are also examples in ‘heavier’ engineering, such as aerospace and civil engineering structures. The subject of this Special Issue is applications of SMPs that have been practically realised. The manufacture of the SMP devices concerned is considered to be an intrinsic part of the application process and is within the scope of the Special Issue. Shape memory polymer composite devices are also included in the scope of the issue. There is no restriction on the application areas.

Prof. John Sweeney
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • shape memory polymer
  • engineering
  • manufacturing
  • composites
  • trigger mechanism

Published Papers (4 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

16 pages, 4112 KiB  
Article
Applications and Life Cycle Assessment of Shape Memory Polyethylene Terephthalate in Concrete for Crack Closure
by Riccardo Maddalena, John Sweeney, Jack Winkles, Cristina Tuinea-Bobe, Brunella Balzano, Glen Thompson, Noemi Arena and Tony Jefferson
Polymers 2022, 14(5), 933; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14050933 - 25 Feb 2022
Cited by 7 | Viewed by 1801
Abstract
Shape memory polymer (SMP) products have been developed for application as crack closure devices in concrete. They have been made from PET in the form of both fibres and hollow tubes. Here, manufacturing methods using die-drawing and mandrel-drawing to induce shape memory are [...] Read more.
Shape memory polymer (SMP) products have been developed for application as crack closure devices in concrete. They have been made from PET in the form of both fibres and hollow tubes. Here, manufacturing methods using die-drawing and mandrel-drawing to induce shape memory are reported. The fibre-based devices are incorporated into concrete and, upon triggering, exert shrinkage restraint forces that close cracks in the concrete. The evolution of shrinkage restraint force in the fibres as manufactured was measured as a function of temperature, showing stresses in excess of 35 MPa. Tendons consisting of fibre bundles are incorporated into concreate beams subjected to controlled cracking. When activated, the tendons reduce the crack widths by 80%. The same fibres are used to produce another class of device known as knotted fibres, which have knotted ends that act as anchor points when they incorporated directly into concrete. Upon activation within the cracked concrete, these devices are shown to completely close cracks. The tubes are used to enclose and restrain prestressed Kevlar fibres. When the tubes are triggered, they shrink and release the prestress force in the Kevlar, which is transferred to the surrounding concrete in the form of a compressive force, thereby closing cracks. The Kevlar fibres also provide substantial reinforcement after activation. The devices are shown to be able to partially and fully close cracks that have been opened to 0.3 mm and achieve post-activation flexural strengths comparable to those of conventional reinforced and prestressed structural elements. Finally, a preliminary life cycle assessment study was used to assess the carbon footprint a nominal unit of concrete made with SMPs fibres compared to conventional concrete. Full article
Show Figures

Graphical abstract

26 pages, 87082 KiB  
Article
Body-Temperature Programmable Soft-Shape Memory Hybrid Sponges for Comfort Fitting
by Balasundaram Selvan Naveen, Azharuddin Bin Mohamed Naseem, Catherine Jia Lin Ng, Jun Wei Chan, Rayner Zheng Xian Lee, Leonard Ee Tong Teo, Taoxi Wang, Mathews Nripan and Wei Min Huang
Polymers 2021, 13(20), 3501; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13203501 - 12 Oct 2021
Cited by 5 | Viewed by 1941
Abstract
Porous shape memory hybrids are fabricated with different matrix (silicone) hardness and different inclusion (polycaprolactone, PCL) ratios. They are characterized to obtain their mechanical response to cyclic loads (with/without pre-straining/programming) and their shape memory performances after body-temperature programming are investigated. These materials are [...] Read more.
Porous shape memory hybrids are fabricated with different matrix (silicone) hardness and different inclusion (polycaprolactone, PCL) ratios. They are characterized to obtain their mechanical response to cyclic loads (with/without pre-straining/programming) and their shape memory performances after body-temperature programming are investigated. These materials are lightweight due to their porous structures. Wetted hydrogels used in the fabrication process for creating pores are reusable and hence this process is eco-friendly. These porous shape memory hybrids exhibit the good shape memory effect of around 90% with higher inclusion (PCL) ratios, which is better than the solid versions reported in the literature. Hence, it is concluded that these materials have great potential to be used in, for instance, insoles and soles for comfort fitting, as demonstrated. Full article
Show Figures

Graphical abstract

9 pages, 2782 KiB  
Article
Self-Restoring Capacitive Pressure Sensor Based on Three-Dimensional Porous Structure and Shape Memory Polymer
by Byunggeon Park, Young Jung, Jong Soo Ko, Jinhyoung Park and Hanchul Cho
Polymers 2021, 13(5), 824; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13050824 - 08 Mar 2021
Cited by 12 | Viewed by 2787
Abstract
Highly flexible and compressible porous polyurethane (PU) structures have effectively been applied in capacitive pressure sensors because of the good elastic properties of the PU structures. However, PU porous structure-based pressure sensors have been limited in practical applications owing to their low durability [...] Read more.
Highly flexible and compressible porous polyurethane (PU) structures have effectively been applied in capacitive pressure sensors because of the good elastic properties of the PU structures. However, PU porous structure-based pressure sensors have been limited in practical applications owing to their low durability during pressure cycling. Herein, we report a flexible pressure sensor based on a three-dimensional porous structure with notable durability at a compressive pressure of 500 kPa facilitated by the use of a shape memory polymer (SMP). The SMP porous structure was fabricated using a sugar templating process and capillary effect. The use of the SMP resulted in the maintenance of the sensing performance for 100 cycles at 500 kPa; the SMP can restore its original shape within 30 s of heating at 80 °C. The pressure sensor based on the SMP exhibited a higher sensitivity of 0.0223 kPa−1 than a typical PU-based sensor and displayed excellent sensing performance in terms of stability, response time, and hysteresis. Additionally, the proposed sensor was used to detect shoe insole pressures in real time and exhibited remarkable durability and motion differentiation. Full article
Show Figures

Figure 1

Review

Jump to: Research

25 pages, 3377 KiB  
Review
Fused Filament Fabrication-4D-Printed Shape Memory Polymers: A Review
by Sara Valvez, Paulo N. B. Reis, Luca Susmel and Filippo Berto
Polymers 2021, 13(5), 701; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13050701 - 26 Feb 2021
Cited by 33 | Viewed by 3924
Abstract
Additive manufacturing (AM) is the process through which components/structures are produced layer-by-layer. In this context, 4D printing combines 3D printing with time so that this combination results in additively manufactured components that respond to external stimuli and, consequently, change their shape/volume or modify [...] Read more.
Additive manufacturing (AM) is the process through which components/structures are produced layer-by-layer. In this context, 4D printing combines 3D printing with time so that this combination results in additively manufactured components that respond to external stimuli and, consequently, change their shape/volume or modify their mechanical properties. Therefore, 4D printing uses shape-memory materials that react to external stimuli such as pH, humidity, and temperature. Among the possible materials with shape memory effect (SME), the most suitable for additive manufacturing are shape memory polymers (SMPs). However, due to their weaknesses, shape memory polymer compounds (SMPCs) prove to be an effective alternative. On the other hand, out of all the additive manufacturing techniques, the most widely used is fused filament fabrication (FFF). In this context, the present paper aims to critically review all studies related to the mechanical properties of 4D-FFF materials. The paper provides an update state of the art showing the potential of 4D-FFF printing for different engineering applications, maintaining the focus on the structural integrity of the final structure/component. Full article
Show Figures

Figure 1

Back to TopTop