Browse
Submit Data
Databases
API
Help

Dataset Information

15 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

High Cycle-life Shape Memory Polymer at High Temperature.

ABSTRACT: High cycle-life is important for shape memory materials exposed to numerous cycles, and here we report shape memory polyimide that maintained both high shape fixity (Rf) and shape recovery (Rr) during the more than 1000 bending cycles tested. Its critical stress is 2.78 MPa at 250?°C, and the shape recovery process can produce stored energy of 0.218?J g(-1) at the efficiency of 31.3%. Its high Rf is determined by the large difference in storage modulus at rubbery and glassy states, while the high Rr mainly originates from its permanent phase composed of strong ?-? interactions and massive chain entanglements. Both difference in storage modulus and overall permanent phase were preserved during the bending deformation cycles, and thus high Rf and Rr were observed in every cycle and the high cycle-life will expand application areas of SMPs enormously.

SUBMITTER: Kong D

PROVIDER: S-EPMC5027533 | biostudies-other | 2016

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

High Cycle-life Shape Memory Polymer at High Temperature.

Kong Deyan D Xiao Xinli X

Scientific reports 20160919

High cycle-life is important for shape memory materials exposed to numerous cycles, and here we report shape memory polyimide that maintained both high shape fixity (Rf) and shape recovery (Rr) during the more than 1000 bending cycles tested. Its critical stress is 2.78 MPa at 250 °C, and the shape recovery process can produce stored energy of 0.218 J g(-1) at the efficiency of 31.3%. Its high Rf is determined by the large difference in storage modulus at rubbery and glassy states, while the hig ...[more]

PMID: 27641148

Similar Datasets

High-Temperature-Induced Shape Memory Copolyimide.

Project description:A series of polyimide (PI) films with a high-temperature-induced shape memory effect and tunable properties were prepared via the facile random copolymerization of 4,4'-oxydianiline (ODA) with 4,4'-(hexafluoroisopropyl)diphthalic anhydride (6FDA) and 4,4'-oxydiphthalic anhydride (ODPA). The trigger temperature can be controlled from 294 to 326 °C by adjusting the ratio of monomers. The effects of monomer rigidity on the chain mobility, physical properties, and shape memory performance of as-prepared copolyimide were systematically investigated. The introduction of ODPA could enhance the mobility of PI macromolecular chains, which made chain entanglement more likely to occur and increased the physical crosslinking density, thereby improving the PI's shape recovery up to 97%. Meanwhile, the existence of 6FDA enabled PI films to set quickly at low temperatures with a shape fixation of 98%. The shape memory cycling characteristics of the polyimide films are also studied, and the relationship between the PI chemical structure and the film properties are further discussed.

| S-EPMC8512334 | biostudies-literature

A Self-Healing and Shape Memory Polymer that Functions at Body Temperature.

Project description:Dual-functional polymeric system combining shape memory with self-healing properties has attracted increasingly interests of researchers, as both of these properties are intelligent and promising characteristics. Moreover, shape memory polymer that functions at human body temperature (37 °C) are desirable because of their potential applications in biomedical field. Herein, we designed a polymer network with a permanent covalent crosslinking and abundant weak hydrogen bonds. The former introduces elasticity responsible and maintain the permanent shape, and the latter contributes to the temporary shape via network rearrangement. The obtained PDMS-COO-E polymer films exhibit excellent mechanical properties and the capability to efficiently self-heal for 6 h at room temperature. Furthermore, the samples turn from a viscous state into an elastic state at 37 °C. Therefore, this polymer has shape memory effects triggered by body temperature. This unique material will have a wide range of applications in many fields, containing wearable electronics, biomedical devices, and 4D printing.

| S-EPMC6767172 | biostudies-literature

High-Temperature Shape Memory Behavior of Semicrystalline Polyamide Thermosets.

Project description:We have explored semicrystalline poly(decamethylene terephthalamide) (PA 10T) based thermosets as single-component high-temperature (>200 °C) shape memory polymers (SMPs). The PA 10T thermosets were prepared from reactive thermoplastic precursors. Reactive phenylethynyl (PE) functionalities were either attached at the chain termini or placed as side groups along the polymer main chain. The shape fixation and recovery performance of the thermoset films were investigated using a rheometer in torsion mode. By controlling the Mn of the reactive oligomers, or the PE concentration of the PE side-group functionalized copolyamides, we were able to design dual-shape memory PA 10T thermosets with a broad recovery temperature range of 227-285 °C. The thermosets based on the 1000 g mol-1 reactive PE precursor and the copolyamide with 15 mol % PE side groups show the highest fixation rate (99%) and recovery rate (?90%). High temperature triple-shape memory behavior can be achieved as well when we use the melt transition ( Tm ? 200 °C) and the glass transition ( Tg = ?125 °C) as the two switches. The recovery rate of the two recovery steps are highly dependent on the crystallinity of the thermosets and vary within a wide range of 74%-139% and 40-82% for the two steps, respectively. Reversible shape memory events could also be demonstrated when we perform a forward and backward deformation in a triple shape memory cycle. We also studied the angular recovery velocity as a function of temperature, which provides a thermokinematic picture of the shape recovery process and helps to program for desired shape memory behavior.

| S-EPMC5994727 | biostudies-literature

Temperature-memory polymer actuators.

Project description:Reading out the temperature-memory of polymers, which is their ability to remember the temperature where they were deformed recently, is thus far unavoidably linked to erasing this memory effect. Here temperature-memory polymer actuators (TMPAs) based on cross-linked copolymer networks exhibiting a broad melting temperature range (ΔT(m)) are presented, which are capable of a long-term temperature-memory enabling more than 250 cyclic thermally controlled actuations with almost constant performance. The characteristic actuation temperatures T(act)s of TMPAs can be adjusted by a purely physical process, guiding a directed crystallization in a temperature range of up to 40 °C by variation of the parameter T(sep) in a nearly linear correlation. The temperature T(sep) divides ΔT(m) into an upper T(m) range (T > T(sep)) forming a reshapeable actuation geometry that determines the skeleton and a lower T(m) range (T < T(sep)) that enables the temperature-controlled bidirectional actuation by crystallization-induced elongation and melting-induced contraction. The macroscopic bidirectional shape changes in TMPAs could be correlated with changes in the nanostructure of the crystallizable domains as a result of in situ X-ray investigations. Potential applications of TMPAs include heat engines with adjustable rotation rate and active building facades with self-regulating sun protectors.

| S-EPMC3732955 | biostudies-literature

High performance shape memory polymer networks based on rigid nanoparticle cores.

Project description:Smart materials that can respond to external stimuli are of widespread interest in biomedical science. Thermal-responsive shape memory polymers, a class of intelligent materials that can be fixed at a temporary shape below their transition temperature (T(trans)) and thermally triggered to resume their original shapes on demand, hold great potential as minimally invasive self-fitting tissue scaffolds or implants. The intrinsic mechanism for shape memory behavior of polymers is the freezing and activation of the long-range motion of polymer chain segments below and above T(trans), respectively. Both T(trans) and the extent of polymer chain participation in effective elastic deformation and recovery are determined by the network composition and structure, which are also defining factors for their mechanical properties, degradability, and bioactivities. Such complexity has made it extremely challenging to achieve the ideal combination of a T(trans) slightly above physiological temperature, rapid and complete recovery, and suitable mechanical and biological properties for clinical applications. Here we report a shape memory polymer network constructed from a polyhedral oligomeric silsesquioxane nanoparticle core functionalized with eight polyester arms. The cross-linked networks comprising this macromer possessed a gigapascal-storage modulus at body temperature and a T(trans) between 42 and 48 degrees C. The materials could stably hold their temporary shapes for > 1 year at room temperature and achieve full shape recovery <or= 51 degrees C in a matter of seconds. Their versatile structures allowed for tunable biodegradability and biofunctionalizability. These materials have tremendous promise for tissue engineering applications.

| S-EPMC2867873 | biostudies-other

Shape memory polymers with high and low temperature resistant properties.

Project description:High temperature shape memory polymers that can withstand the harsh temperatures for durable applications are synthesized, and the aromatic polyimide chains with flexible linkages within the backbone act as reversible phase. High molecular weight (Mn) is demanded to form physical crosslinks as fixed phase of thermoplastic shape memory polyimide, and the relationship between Mn and glass transition temperature (Tg) is explored. Thermoset shape memory polyimide shows higher Tg and storage modulus, better shape fixity than thermoplastic counterpart due to the low-density covalent crosslinking, and the influence of crosslinking on physical properties are studied. The mechanism of high temperature shape memory effects based on chain flexibility, molecular weight and crosslink density is proposed. Exposure to thermal cycling from +150?°C to -150?°C for 200 h produces negligible effect on the properties of the shape memory polyimide, and the possible mechanism of high and low temperature resistant property is discussed.

| S-EPMC4585657 | biostudies-other

A strategy of designing high-entropy alloys with high-temperature shape memory effect.

Project description:Shape memory effect, the ability to recover a pre-deformed shape on heating, results from a reversible martensitic transformation between austenite and martensite phases. Here, we demonstrate a strategy of designing high-entropy alloys (HEAs) with high-temperature shape memory effect in the CrMnFeCoNi alloy system. First, we calculate the difference in Gibbs free energy between face-centered-cubic (FCC) and hexagonal-close-packed (HCP) phases, and find a substantial increase in thermodynamic equilibrium temperature between the FCC and HCP phases through composition tuning, leading to thermally- and stress-induced martensitic transformations. As a consequence, the shape recovery temperature in non-equiatomic CrMnFeCoNi alloys can be increased to 698?K, which is much higher than that of conventional shape memory alloys (SMAs) and comparable to that of B2-based multi-component SMAs containing noble metals (Pd, Pt, etc.) or refractory metals (Zr, Hf, etc.). This result opens a vast field of applications of HEAs as a novel class of cost-effective high-temperature SMAs.

| S-EPMC6739314 | biostudies-literature

4D Printing of Recyclable Lightweight Architectures Using High Recovery Stress Shape Memory Polymer.

Project description:High-performance lightweight architectures, such as metallic microlattices with excellent mechanical properties have been 3D printed, but they do not possess shape memory effect (SME), limiting their usages for advanced engineering structures, such as serving as a core in multifunctional lightweight sandwich structures. 3D printable self-healing shape memory polymer (SMP) microlattices could be a solution. However, existing 3D printable thermoset SMPs are limited to either low strength, poor stress memory, or non-recyclability. To address this issue, a new thermoset polymer, integrated with high strength, high recovery stress, perfect shape recovery, good recyclability, and 3D printability using direct light printing, has been developed in this study. Lightweight microlattices with various unit cells and length scales were printed and tested. The results show that the cubic microlattice has mechanical strength comparable to or even greater than that of metallic microlattices, good SME, decent recovery stress, and recyclability, making it the first multifunctional lightweight architecture (MLA) for potential multifunctional lightweight load carrying structural applications.

| S-EPMC6527608 | biostudies-literature

Photonic Shape Memory Polymer with Stable Multiple Colors.

Project description:A photonic shape memory polymer film that shows large color response (?155 nm) in a wide temperature range has been fabricated from a semi-interpenetrating network of a cholesteric polymer and poly(benzyl acrylate). The large color response is achieved by mechanical embossing of the photonic film above its broad glass transition temperature. The embossed film, as it recovers to its original shape on heating through the broad thermal transition, exhibits multiple structural colors ranging from blue to orange. The relaxation behavior of the embossed film can be fully described using a Kelvin-Voigt model, which reveals that the influence of temperature on the generation of colors is much stronger than that of time, thereby producing stable multiple colors.

| S-EPMC5609120 | biostudies-literature

Shape Memory Polymer Foams with Tunable Degradation Profiles.

Project description:Uncontrolled hemorrhage is the leading cause of preventable death on the battlefield and results in ∼1.5 million deaths each year. The primary current treatment options are gauze and/or tourniquets, which are ineffective for up to 80% of wounds. Additionally, most hemostatic materials must be removed from the patient within <12 h, which limits their applicability in remote scenarios and can cause additional bleeding upon removal. Here, degradable shape memory polymer (SMP) foams were synthesized to overcome these limitations. SMP foams were modified with oxidatively labile ether groups and hydrolytically labile ester groups to degrade after implantation. Foam physical, thermal, and shape memory properties were assessed along with cytocompatibility and blood interactions. Degradation profiles were obtained in vitro in oxidative and hydrolytic media (3% H2O2 (oxidation) and 0.1 M NaOH (hydrolysis) at 37 °C). The resulting foams had tunable, clinically relevant degradation rates, with complete mass loss within 30-60 days. These SMP foams have potential to provide an easy-to-use, shape-filling hemostatic dressing that can be left in place during traumatic wound healing with future potential use in regenerative medicine applications.

| S-EPMC8456454 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data