scholarly journals In Situ Generation of Green Hybrid Nanofibrillar Polymer-Polymer Composites—A Novel Approach to the Triple Shape Memory Polymer Formation

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1900
Author(s):  
Ramin Hosseinnezhad ◽  
Iurii Vozniak ◽  
Fahmi Zaïri
Keyword(s):  
Polymer Blends ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Cellulose Nanofibers ◽  
Polymeric Materials ◽  
Novel Approach ◽  
Phase Transition Temperatures ◽  
Triple Shape Memory

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

scholarly journals A Mechanical Analysis of Chemically Stimulated Linear Shape Memory Polymer Actuation

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 481
Author(s):  
Hakan Dumlu ◽  
Axel Marquardt ◽  
Elias M. Zirdehi ◽  
Fathollah Varnik ◽  
Yucen Shen ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Mechanical Analysis ◽  
Micromechanical Modeling ◽  
Glass Temperature ◽  
Elementary Processes ◽  
Linear Shape

In the present work, we study the role of programming strain (50% and 100%), end loads (0, 0.5, 1.0, and 1.5 MPa), and chemical environments (acetone, ethanol, and water) on the exploitable stroke of linear shape memory polymer (SMP) actuators made from ESTANE ETE 75DT3 (SMP-E). Dynamic mechanical thermal analysis (DMTA) shows how the uptake of solvents results in a decrease in the glass temperature of the molecular switch component of SMP-E. A novel in situ technique allows studying chemically triggered shape recovery as a function of time. It is found that the velocity of actuation decreases in the order acetone > ethanol > water, while the exploitable strokes show the inverse tendency and increases in the order water > ethanol > acetone. The results are interpreted on the basis of the underlying chemical (how solvents affect thermophysical properties) and micromechanical processes (the phenomenological spring dashpot model of Lethersich type rationalizes the behavior). The study provides initial data which can be used for micromechanical modeling of chemically triggered actuation of SMPs. The results are discussed in the light of underlying chemical and mechanical elementary processes, and areas in need of further work are highlighted.

A new approach to characterization of the transition temperatures of thin film NiTi shape memory alloys

2004 ◽  
Vol 19 (6) ◽  
pp. 1762-1767
Author(s):  
Nicholas W. Botterill ◽  
David M. Grant ◽  
Jianxin Zhang ◽  
Clive J. Roberts
Keyword(s):  
Thin Film ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transition Temperatures ◽  
New Approach ◽  
Novel Approach ◽  
Potential Applications ◽  
Niti Shape Memory Alloys

A novel approach in determining the transition temperatures of NiTi shape memory alloys was investigated and compared with conventional techniques. The technique is based on microthemal analysis using a scanning thermal microscope (SThM). In particular, this method has the potential to allow the transformation temperatures of thin films to be investigated in situ. Thin film shape memory alloys have potential applications, such as microactuators, where conventional analysis techniques are either not directly applicable to such samples or are difficult to perform.

In Situ Reversible Tuning from Pinned to Roll-Down Superhydrophobic States on a Thermal-Responsive Shape Memory Polymer by a Silver Nanowire Film

2020 ◽  
Vol 12 (11) ◽  
pp. 13464-13472 ◽  
Author(s):  
Chuanzong Li ◽  
Yunlong Jiao ◽  
Xiaodong Lv ◽  
Sizhu Wu ◽  
Chao Chen ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Silver Nanowire

Digital Light Processing 3D Printing of Triple Shape Memory Polymer for Sequential Shape Shifting

2019 ◽  
Vol 1 (4) ◽  
pp. 410-417 ◽  
Author(s):  
Bangan Peng ◽  
Yunchong Yang ◽  
Kai Gu ◽  
Eric J. Amis ◽  
Kevin A. Cavicchi
Keyword(s):  
3D Printing ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Digital Light Processing ◽  
Triple Shape Memory

Using Multiscale Modeling to Predict Material Response of Polymeric Materials

2009 ◽  
Author(s):  
Richard V. Beblo ◽  
Lisa Mauck Weiland
Keyword(s):  
Shape Memory ◽  
Multiscale Modeling ◽  
Shape Memory Polymer ◽  
Polymeric Materials ◽  
Scale Model ◽  
Molecular Formula ◽  
Thermal Stimulus ◽  
Rotational Isomeric State ◽  
New Class ◽  
Constraint Theory

Presented is a multiscale modeling method applied to light activated shape memory polymers (LASMP). LASMP are a new class of shape memory polymer (SMP) being developed for applications where a thermal stimulus is undesired. Rotational Isomeric State (RIS) theory is used to build a molecular scale model of the polymer chain yielding a list of distances between the predicted cross-link locations, or r-values. The r-values are then fit with Johnson probability density functions and used with Boltzmann statistical mechanics to predict stress as a function of strain of the phantom network. Junction constraint theory is then used to calculate the stress contribution due to interactions with neighboring chains, resulting in previously unattainable numerically accurate Young’s modulus predictions based on the molecular formula of the polymer. The system is modular in nature and thus lends itself well to being adapted for specific applications. The results of the model are presented with experimental data for confirmation of correctness along with discussion of the potential of the model to be used to computationally adjust the chemical composition of LASMP to achieve specified material characteristics, greatly reducing the time and resources required for formula development.

Sign in / Sign up

Export Citation Format

Share Document