Characterizations of Silicon Carbide Whisker-Filled in Benzoxazine-Epoxy Shape Memory Polymers

2015 ◽  
Vol 659 ◽  
pp. 373-377 ◽  
Author(s):  
Chutiwat Likitaporn ◽  
Sarawut Rimdusit

Shape memory polymers (SMPs) are polymer materials that can fix the temporary shape and then recover to their original permanent shape by external stimulation, i.e. applied heat. In this research, shape memory polymer composites (SMPCs) from benzoxazine (BA-a)-epoxy binary systems reinforced with adamantine silicon carbide whisker (SiCw) are investigated. The SiCw contents are controlled to be in range of 0 to 15% by weight. All specimens were fabricated by compression molding technique. The results revealed that the shape memory polymer composites showed higher glassy state storage modulus with increasing amount of the whisker suggesting substantial reinforcement effect of the whisker used. The glass transition temperature (Tg) was also improved from 102°C of the based polymer to the value about 122°C with the addition of about 15% by weight of the silicon carbide whisker. Finally, shape recovery stress systematically increased from the value about 1.5MPa of the unfilled polymer matrix to the value about 3.2MPa with an addition of 15% by weight of the silicon carbide whisker. The positive effect on thermal stability from SiCw addition is expected from the modification and will be reported in this work.

Author(s):  
L. Santo ◽  
L. Iorio ◽  
G. M. Tedde ◽  
F. Quadrini

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.


2018 ◽  
Vol 55 (4) ◽  
pp. 494-497
Author(s):  
Giovanni Matteo Tedde ◽  
Loredana Santo ◽  
Denise Bellisario ◽  
Leandro Iorio ◽  
Fabrizio Quadrini

Shape Memory Polymer Composites (SMPCs) are a class of smart materials in which the structural properties of long-fiber polymer-matrix composites and the functional behavior of Shape Memory Polymers (SMP) are combined together. In this study, the frozen stresses resulting from fixing a deformed shape have been investigated. Two different samples were manufactured, with and without significant shape memory properties, and a three point flexural test equipment was used in order to fix a deformed shape. The forces and the resulting stresses were measured during the samples deformation and after the shape freezing. The experimental tests have shown that the shape memory sample has a better ability to fix a deformed shape, since its frozen stress is higher in all the tests.


2016 ◽  
Vol 853 ◽  
pp. 96-100 ◽  
Author(s):  
Jian Li ◽  
Shi Yu Dong ◽  
Qian Hua Kan ◽  
Guo Zheng Kang ◽  
Wen Yi Yan

Glassy shape memory polymer materials are applied successfully in biomedical fields due to their large recovery deformation, excellent biocompatibility and unique biodegradability. To predict the thermo-mechanical behavior of glassy shape memory polymers in biomedical devices accurately, a reasonably three-dimensional thermo-mechanical constitutive model must be established firstly. A one-dimensional linear-elastic constitutive model proposed by Tobushi et. al. (1997) was extended to capture the loading level dependent degradation of shape memory effect by introducing new nonlinear evolution equations with threshold values. Comparisons between experiments and simulations were carried to validate the extended model. Simulation results agree with experiments well, especially for the high loading levels.


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.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wang Zhang ◽  
Hao Wang ◽  
Hongtao Wang ◽  
John You En Chan ◽  
Hailong Liu ◽  
...  

AbstractFour-dimensional (4D) printing of shape memory polymer (SMP) imparts time responsive properties to 3D structures. Here, we explore 4D printing of a SMP in the submicron length scale, extending its applications to nanophononics. We report a new SMP photoresist based on Vero Clear achieving print features at a resolution of ~300 nm half pitch using two-photon polymerization lithography (TPL). Prints consisting of grids with size-tunable multi-colours enabled the study of shape memory effects to achieve large visual shifts through nanoscale structure deformation. As the nanostructures are flattened, the colours and printed information become invisible. Remarkably, the shape memory effect recovers the original surface morphology of the nanostructures along with its structural colour within seconds of heating above its glass transition temperature. The high-resolution printing and excellent reversibility in both microtopography and optical properties promises a platform for temperature-sensitive labels, information hiding for anti-counterfeiting, and tunable photonic devices.


2016 ◽  
Vol 08 (07) ◽  
pp. 1640009 ◽  
Author(s):  
Fengfeng Li ◽  
Liwu Liu ◽  
Xin Lan ◽  
Tong Wang ◽  
Xiangyu Li ◽  
...  

With large spatial deployable antennas used more widely, the stability of deployable antennas is attracting more attention. The form of the support structure is an important factor of the antenna’s natural frequency, which is essential to study to prevent the resonance. The deployable truss structures based on shape memory polymer composites (SMPCs) have made themselves feasible for their unique properties such as highly reliable, low-cost, light weight, and self-deployment without complex mechanical devices compared with conventional deployable masts. This study offers deliverables as follows: an establishment of three-longeron beam and three-longeron truss finite element models by using ABAQUS; calculation of natural frequencies and vibration modes; parameter studies for influence on their dynamic properties; manufacture of a three-longeron truss based on SMPC, and modal test of the three-longeron truss. The results show that modal test and finite element simulation fit well.


2020 ◽  
Vol 11 (7) ◽  
pp. 1369-1374 ◽  
Author(s):  
Wusha Miao ◽  
Weike Zou ◽  
Yingwu Luo ◽  
Ning Zheng ◽  
Qiao Zhao ◽  
...  

Polycaprolactone based thermadapt shape memory polymers with precisely controlled structures allow tunable shape reconfigurability.


2011 ◽  
Vol 78 (6) ◽  
Author(s):  
Richard V. Beblo ◽  
Lisa Mauck Weiland

Presented are the experimental results of two light activated shape memory polymer (LASMP) formulations. The optical stimulus used to activate the materials is detailed including a mapping of the spatial optical intensity at the surface of the sample. From this, results of energy calculations are presented including the amount of energy available for transitioning from the glassy state to the rubbery state and from the rubbery state to the glassy state, highlighting one of the major advantages of LASMP as requiring less energy to transition than thermally activated shape memory polymers. The mechano-optical experimental setup and procedure is detailed and provides a consistent method for evaluating this relatively new class of shape memory polymer. A chemical kinetic model is used to predict both the theoretical glassy state modulus, as only the sample averaged modulus is experimentally attainable, as well as the through thickness distribution of Young’s modulus. The experimental and model results for these second generation LASMP formulations are then compared with earlier LASMP generations (detailed previously in Beblo and Mauck Weiland, 2009, “Light Activated Shape Memory Polymer Characterization,” ASME J. Appl. Mech., 76, pp. 8) and typical thermally activated shape memory polymer.


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