Processing and Characterization of Novel Bismaleimide-Based Shape Memory Polymer Composites

2012 ◽  
Author(s):  
G. P. Tandon ◽  
T. Gibson ◽  
J. Shumaker ◽  
R. Coomer ◽  
J. Baur ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Cure Kinetics ◽  
Mechanical Analysis ◽  
Void Content ◽  
Variable Cross ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Expansion System ◽  
Memory Cycle

In the present study, a series of novel linear polyaspartimide-based silane endcapped (cross-linked) polymers are synthesized using 4-4′ bismaleimidodiphenylmethane, Jeffamine D-400 (BMI-JA-400), and (3-Aminopropyl) trimethoxysilane. To add strength to these systems, the trimethoxysilane moiety is cross-linked with the addition of water to create a thermosetting material with both improved toughness and variable cross-link densities. Thermal analysis is done to evaluate the developed shape-memory polymer (SMP) resin for composite processing feasibility. The solvent content in the resin and thermal stability is monitored using thermogravimetric analysis (TGA) while advanced rheometric expansion system (ARES) with parallel plate geometry is used to measure viscosity variation with temperature. The resin BMI-JA-400-Si-70/30 is chosen for making the composite based on its viscosity, weight change, and kinetic results. Differential scanning calorimetry (DSC) is performed to determine the cure kinetics including the temperatures at which the cure reaction initiates and completes in order to develop the cure cycle for composite fabrication. The selected SMP resin is hand-impregnated with T-300 plain-weave and T-700 uni-weave carbon fabric. Six-ply composites are successfully fabricated with < 2% void content using both fabric weaves. The thermo-mechanical properties of the SMP resin are measured using dynamic mechanical analysis (DMA). In addition, the shape memory cycle with free recovery is conducted on the SMP resin and composites.

Cross-linked ethylene-vinyl acetate – poly(urethane) temperature-memory composite actuator

2020 ◽  
Vol 54 (28) ◽  
pp. 4441-4455
Author(s):  
JE Rodriguez ◽  
DH Giraldo ◽  
JC Restrepo ◽  
HA Colorado
Keyword(s):  
Shape Memory ◽  
Vinyl Acetate ◽  
Shape Memory Polymer ◽  
Ethylene Vinyl Acetate ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Polymeric Systems ◽  
Responsive Polymers ◽  
The Matrix ◽  
The Relationship

Semicrystalline polymeric systems are a type of Shape Memory Polymer (SMP), which are more straightforward to synthesize in comparison with other class of stimulus-responsive polymers. On these systems, the shape memory is triggered by temperature and partially driven by crystallization-induced elongation, heating-induced contraction, and elastic entropy. However, a stable temporary and permanent shape through cycling is not easy to achieve. For that reason, a laminar composite made based in the encapsulation of ethylene vinyl acetate (EVA) inside a PU matrix was developed, with the aim of obtaining an actuator with a preferred deformation direction and stable change of shape. In this study, chemically cross-linked ethylene vinyl acetate copolymer (cEVA) as SMP was synthesized and functionalized as a reinforcing strip. A temperature-memory actuator composite was manufactured by the encapsulation of a shape memory programmed strip in an elastomer matrix. The shape memory properties and thermocycling assessment were evaluated using differential scanning calorimetry and dynamic mechanical analysis. Results show the ability of the actuator to bend and unbend, following multiple consecutive heating-cooling cycles. The relationship between the strip, the matrix, and the interface is critical in the bending and shape memory maintenance.

Effect of C12-14 Alcohols on the Thermomechanical Properties of Epoxy Shape-Memory Polymer

2014 ◽  
Vol 787 ◽  
pp. 275-280
Author(s):  
Li Min Zhao ◽  
Xue Feng ◽  
Xu Jun Mi ◽  
Yan Feng Li ◽  
Hao Feng Xie ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Shape Memory ◽  
Room Temperature ◽  
Aliphatic Alcohol ◽  
Shape Memory Polymer ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Epoxy System ◽  
Scanning Calorimetry ◽  
Epoxy Polymers

A critical parameter for a shape memory polymer (SMP) lies in its shape memory transition temperature. For an amorphous SMP polymer, it is highly desirable to develop methods to tailor its Tg, which corresponds to its shape memory transition temperature. Starting with an amine cured aromatic epoxy system, epoxy polymers were synthesized by introducing flexible aliphatic alcohol. The thermal and thermomechanical properties of these epoxy polymers were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). All the crosslinked epoxy polymers with Tg’s above room temperature were found to possess shape memory properties.

scholarly journals The Effect of POSS Type on the Shape Memory Properties of Epoxy-Based Nanocomposites

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4203
Author(s):  
Avraham I. Bram ◽  
Irina Gouzman ◽  
Asaf Bolker ◽  
Noam Eliaz ◽  
Ronen Verker
Keyword(s):  
Transition Temperature ◽  
Shape Memory ◽  
Crosslinking Density ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Space Environment ◽  
Scanning Calorimetry ◽  
Space Applications ◽  
Curing Conditions ◽  
Oligomeric Silsesquioxane

Thermally activated shape memory polymers (SMPs) can memorize a temporary shape at low temperature and return to their permanent shape at higher temperature. These materials can be used for light and compact space deployment mechanisms. The control of transition temperature and thermomechanical properties of epoxy-based SMPs can be done using functionalized polyhedral oligomeric silsesquioxane (POSS) additives, which are also known to improve the durability to atomic oxygen in the space environment. In this study, the influence of varying amounts of two types of POSS added to epoxy-based SMPs on the shape memory effect (SME) were studied. The first type contained amine groups, whereas the second type contained epoxide groups. The curing conditions were defined using differential scanning calorimetry and glass transition temperature (Tg) measurements. Thermomechanical and SME properties were characterized using dynamic mechanical analysis. It was found that SMPs containing amine-based POSS show higher Tg, better shape fixity and faster recovery speed, while SMPs containing epoxide-based POSS have higher crosslinking density and show superior thermomechanical properties above Tg. This work demonstrates how the Tg and SME of SMPs can be controlled by the type and amount of POSS in an epoxy-based SMP nanocomposite for future space applications.

scholarly journals Bio-Based Epoxy Shape-Memory Thermosets from Triglycidyl Phloroglucinol

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 542 ◽  
Author(s):  
David Santiago ◽  
Dailyn Guzmán ◽  
Francesc Ferrando ◽  
Àngels Serra ◽  
Silvia De la Flor
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Memory Performance ◽  
Crosslinking Agent ◽  
Shape Memory Polymers ◽  
Crosslinking Density ◽  
Mechanical Analysis ◽  
Diglycidyl Ether ◽  
Partial Substitution ◽  
Scanning Calorimetry

A series of bio-based epoxy shape-memory thermosetting polymers were synthesized starting from a triglycidyl phloroglucinol (3EPOPh) and trimethylolpropane triglycidyl ether (TPTE) as epoxy monomers and a polyetheramine (JEF) as crosslinking agent. The evolution of the curing process was studied by differential scanning calorimetry (DSC) and the materials obtained were characterized by means of DSC, thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), stress-strain tests, and microindentation. Shape-memory properties were evaluated under free and totally constrained conditions. All results were compared with an industrial epoxy thermoset prepared from standard diglycidyl ether of Bisphenol A (DGEBA). Results revealed that materials prepared from 3EPOPh were more reactive and showed a tighter network with higher crosslinking density and glass transition temperatures than the prepared from DGEBA. The partial substitution of 3EPOPh by TPTE as epoxy comonomer caused an increase in the molecular mobility of the materials but without worsening the thermal stability. The shape-memory polymers (SMPs) prepared from 3EPOPh showed good mechanical properties as well as an excellent shape-memory performance. They showed almost complete shape-recovery and shape-fixation, fast shape-recovery rates, and recovery stress up to 7 MPa. The results obtained in this study allow us to conclude that the triglycidyl phloroglucinol derivative of eugenol is a safe and environmentally friendly alternative to DGEBA for preparing thermosetting shape-memory polymers.

Novel shape-memory polyurethane fibers for textile applications

2018 ◽  
Vol 89 (6) ◽  
pp. 1027-1037 ◽  
Author(s):  
Míriam Sáenz-Pérez ◽  
Tariq Bashir ◽  
José Manuel Laza ◽  
Jorge García-Barrasa ◽  
José Luis Vilas ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Shape Memory ◽  
Tensile Testing ◽  
Melt Spinning ◽  
Mechanical Analysis ◽  
Knitted Fabric ◽  
Scanning Calorimetry ◽  
Moisture Management ◽  
Potential Applications ◽  
Shape Memory Polyurethane

In this work, thermoresponsive shape-memory polyurethane (SMPU) fibers were produced by melt spinning from different SMPU pellets. Afterwards, the knitted fabric samples were prepared by the obtained fibers. Some of the SMPUs used were synthesized previously in our laboratory whereas a commercial one, named DIAPLEX MM4520, was also evaluated in order to carry out comparative studies. All the SMPUs were characterized by different techniques, such as thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. Moreover, the shape-memory capabilities of the fabrics were measured by thermo-mechanical analysis. The obtained results show that the synthesized SMPUs could be attractive candidates for potential applications such as breathable fabrics or moisture-management textiles.

scholarly journals Dynamic Cure Kinetics and Physical-Mechanical Properties of PEG/Nanosilica/Epoxy Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Haleh Nowruzi Varzeghani ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Solid Particles ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Cure Kinetic ◽  
Cure Temperature ◽  
Kinetics Of

This study investigated the effect of polyethylene glycol (PEG) and nanosilica (NS) on the physical-mechanical properties and cure kinetics of diglycidyl ether of bisphenol-A-based epoxy (DGEBA-based EP) resin. For this purpose, tensile and viscometry tests, dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC) were carried out under dynamic conditions. The results showed that adding NS and PEG enhances the maximum cure temperature as well as the heat of cure reaction (ΔH) in EP-NS, while it decreases in EP-PEG and EP-PEG-NS. The cure kinetic parameters of EP-PEG-NS were calculated by Kissinger, Ozawa, and KSA methods and compared with each other. The Ea calculated from the Kissinger method (96.82 kJ/mol) was found to be lower than that of the Ozawa method (98.69 kJ/mol). Also, according to the KAS method, the apparent Ea was approximately constant within the 10-90% conversion range. Tensile strength and modulus increased by adding NS, while tensile strength diminished slightly by adding PEG to EP-NS. The glass transition temperature (Tg) was calculated using DMTA which was increased and decreased by the addition of NS and PEG, respectively. The results of the viscometry test showed that the viscosity increased with the presence of both PEG and NS and it prevented the deposition of solid particles.

Carbon Fiber Reinforced Shape Memory Nanocomposites Incorporated With Highly Conductive Carbon Nanopaper for Electro Actuation

2013 ◽  
Author(s):  
Fei Liang ◽  
Jihua Gou ◽  
He Shen ◽  
Yunjun Xu ◽  
Bob Mabbott
Keyword(s):  
Carbon Fiber ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Memory Polymer ◽  
Flexural Modulus ◽  
Fiber Reinforcement ◽  
High Strength ◽  
Mechanical Analysis ◽  
Carbon Fiber Reinforcement ◽  
Continuous Carbon Fiber

Shape memory polymers (SMPs) are one of the most popular smart materials due to light weight and high elastic deformation capability. In this study, highly conductive carbon nanofibers paper (CNFP) was coated on the surface of SMP as a conductive layer for electro actuation of SMP. To overcome the drawback of low modulus and low strength of shape memory polymer (SMP), continuous carbon fiber reinforcement was also incorporated with SMP by autoclave processing. The dynamic mechanical analysis (DMA) result showed over 600% increase of storage modulus of SMP by introducing carbon fiber reinforcement. Also, the shape recovery time of SMP has been reduced over 150%, while the recovery ratio of SMP has been improved to 99% by incorporating with carbon fiber reinforcement. Additionally, the mechanical property degradation of SMP composites has been investigated after different electro actuation cycles. After 50 actuation cycles, the decrease of flexural modulus of SMP composites is negligible (< 2%), and the ultimate flexural strength of SMP composites only decreased 25%. The SMP composite shows high strength and modulus, and good durability.

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