scholarly journals Mechanical, Thermal, and Shape Memory Properties of Three-Dimensional Printing Biomass Composites

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1234 ◽  
Author(s):  
Hongjie Bi ◽  
Min Xu ◽  
Gaoyuan Ye ◽  
Rui Guo ◽  
Liping Cai ◽  
...  

In this study, a series of heat-induced shape memory composites was prepared by the hot-melt extrusion and three-dimensional (3D) printing of thermoplastic polyurethane (TPU) using wood flour (WF) with different contents of EPDM-g-MAH. The mechanical properties, microtopography, thermal property analysis, and heat-induced shape memory properties of the composites were examined. The results showed that, when the EPDM-g-MAH content was 4%, the tensile elongation and tensile strength of the composites reached the maximum value. The scanning electron microscopy and dynamic mechanical analysis results revealed a good interface bonding between TPU and WF when the EPDM-g-MAH content was 4%. The thermogravimetric analysis indicated that the thermal stability of TPU/WF composites was enhanced by the addition of 4% EPDM-g-MAH. Heat-induced shape memory test results showed that the shape memory performance of composites with 4% EPDM-g-MAH was better than that of unmodified-composites. The composites’ shape recovery performance at a temperature of 60 °C was higher than that of the composites at ambient temperature. It was also found that, when the filling angle of the specimen was 45°, the recovery angle of the composites was larger.

2012 ◽  
Vol 476-478 ◽  
pp. 2227-2230
Author(s):  
He Sun ◽  
Yu Yan Liu ◽  
Hui Feng Tan ◽  
Chang Guo Wang

In this paper, a various shape-memory materials had been prepared by two-stage curing method. The purpose of using this approach was to maintain the excellent shape memory properties and low glass transition temperature (Tg) of shape-memory materials after first stage curing, furthermore, improve the Tg and heat resistence effectively after second stage curing. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and fold-deploy shape memory tests were used to characterize the feasibility of two-stage curing, thermodynamics properties and shape memory performance of these polymers. DSC results showed that two different curing stages could be achieved successfully, DMA results suggested that heat resistance of materials had been improved after second curing stage, while the fold-deploy shape memory tests proved that the composites possessed excellent shape memory properties, it could be deformed into different shape and recovered its original shape fully within three minutes.


2020 ◽  
Vol 40 (3) ◽  
pp. 203-210 ◽  
Author(s):  
Tianning Ren ◽  
Guangming Zhu ◽  
Yi Liu ◽  
Xiao Hou

AbstractThe objective of this work is to investigate the thermomechanical, electrical, and shape-memory properties of bisphenol A-type cyanate ester (BACE)/polybutadiene epoxy (PBEP)/carbon black (CB) composite and assess its feasibility applied for deployable structure. Using a BACE/PBEP polymer as matrix and superconducting carbon black (CB) and short carbon fibers (SCFs) as reinforcing material, the shape memory composite was prepared by compression molding. The effects of CB and SCF content on the shape memory properties of the composites were investigated. The results demonstrate that the glass transition temperature (Tg) and the storage modulus of the composites increases as SCFs content increase. Because of the synergic effect of CB and SCFs, the shape memory composites exhibit excellent shape memory performance, and the shape recovery ratio is about 100%. With the increase in SCF content, the recovery time decreased, and the volume electrical resistivity of the composite could decrease by adding a small amount of SCFs. According to the above results, a shape memory polymer composite deployable structure was prepared.


2018 ◽  
Vol 51 (7-8) ◽  
pp. 626-643
Author(s):  
Chengliang Li ◽  
Xingxing Ji ◽  
Yang Lyu ◽  
Xinyan Shi

In this work, a damping material was successfully prepared by blending acrylic rubber (ACM) and polylactide (PLA) with sulfur and soap salt as the curing agents. A phenol-formaldehyde (PF) resin was used as a modifier. The effects of PF on the mechanical properties, damping properties, compatibility and shape memory properties of the blends were studied. The compatibility and damping properties were characterized by dynamic mechanical analysis, Fourier transform infrared spectroscope and microstructure analysis. The shape memory properties were examined by thermal mechanical analyser. The results revealed that the tensile strength of the blends was decreased and the toughness was increased with the increase of PF loadings. The introduction of PF improved the compatibility between PLA and ACM, which was deduced from the fact that the glass transition temperature of ACM was increased and the two loss factor peaks became closer. It was also found that the loss factor peak became higher and the effective damping temperature range became wider due to the formation of hydrogen bonding, implying that the damping properties of ACM/PLA blends were significantly improved. The ACM/PLA blends exhibited good dual-shape memory effect and its shape recovery ratio was increased by introduction of PF and raising the trigger temperature. The blends also exhibited good triple-shape memory property, which was dramatically improved by the introduction of PF. The mechanisms for the enhanced shape memory effects were then analysed.


Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 807 ◽  
Author(s):  
Lin Xia ◽  
Han Gao ◽  
Weina Bi ◽  
Wenxin Fu ◽  
Guixue Qiu ◽  
...  

Shape memory composites of trans-1,4-polyisoprene (TPI) and low-density polyethylene (LDPE) with easily achievable transition temperatures were prepared by a simple physical blending method. Carbon black (CB) was introduced to improve the mechanical properties of the TPI/LDPE composites. The mechanical, cure, thermal and shape memory properties of the TPI/LDPE/CB composites were investigated in this study. In these composites, the crosslinked network generated in both the TPI and LDPE portions acted as a fixed domain, while the crystalline regions of the TPI and LDPE portions acted as a reversible domain in shape memory behavior. We found the mechanical properties of composites were promoted significantly with an increase of CB content, accompanied with the deterioration of shape memory properties of composites. When CB dosage was 5 parts per hundred of rubber composites (phr), best shape memory property of composites was obtained with a shape fixity ratio of 95.1% and a shape recovery ratio of 95.0%.


Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 542 ◽  
Author(s):  
David Santiago ◽  
Dailyn Guzmán ◽  
Francesc Ferrando ◽  
Àngels Serra ◽  
Silvia De la Flor

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.


2018 ◽  
Vol 6 (11) ◽  
pp. 1668-1677 ◽  
Author(s):  
Yongzhen Wang ◽  
Zhongjun Cheng ◽  
Zhenguo Liu ◽  
Hongjun Kang ◽  
Yuyan Liu

The PU/CNF nanocomposites display water-triggered fast shape memory ability, such as curling and unfolding, demonstrating tailored shape memory performance.


2009 ◽  
Vol 1190 ◽  
Author(s):  
Jing Cui ◽  
Karl Kratz ◽  
Andreas Lendlein

AbstractBiocompatible shape-memory polymers are of high significance for application in medical devices or instruments for minimally invasive surgery. To follow the medical device placement or changes in shape of the device in vivo by imaging methods like X-ray techniques, radiopacity of the polymer is required. In this work, we explored the shape-memory properties of radiopaque polymer composites prepared by incorporation of barium sulphate micro-particles in a biomedical grade polyether urethane (PEU) by co-extrusion technique. The filler content was varied from 5 wt% to 40 wt%, which was confirmed by thermal gravimetric analysis (TGA) measurements, while the particle distribution was visualized by scanning electron microscopy (SEM). The thermal and mechanical properties of the composites were investigated by means of dynamic mechanical analysis at varied temperature (DMTA) and tensile tests. The shape-memory properties of PEU composites were quantified in cyclic, thermomechanical experiments. A significant increase in Young’s modulus and a decrease in elongation at break were observed for PEU composites with increasing content of BaSO4, while the DMTA results were not affected by incorporation of the fillers. All samples exhibited excellent shape-memory properties with shape fixity rates (Rf) above 98% and values for shape recovery rate (Rr) in the range of 81% to 93%. The maximum stress (σmax) obtained under constant strain recovery conditions increased from 0.6 MPa to 1.4 MPa with raising amount of BaSO4, while the corresponding temperature (Tσ,max) as well as the switching temperature (Tsw) determined under stress-free conditions remained constant for all polymer composites.


2017 ◽  
Vol 9 (2) ◽  
pp. 1820-1829 ◽  
Author(s):  
Ran Yu ◽  
Xin Yang ◽  
Ying Zhang ◽  
Xiaojuan Zhao ◽  
Xiao Wu ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1107 ◽  
Author(s):  
Zhengwei Yu ◽  
Zhenqing Wang ◽  
Hao Li ◽  
Jianxin Teng ◽  
Lidan Xu

Shape memory epoxy polymer (SMEP) composite specimens with different graphene oxide (GO) contents were manufactured to study the effects of GO mass fractions on epoxy polymer composites. While ensuring the shape memory effect of SMEP, the addition of GO also remarkably strengthened the mechanical performance of the polymers. Analyses of the epoxy polymer composites’ thermal, mechanical, and shape memory performance were conducted through carrying out dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and static tensile, three-point bending, impact, and shape memory tests. Moreover, the tensile fracture, bending fracture, and impact fracture interfaces of epoxy resin composites were examined with scanning electron microscopy. The final test results indicated that when the GO content was 0.8 wt %, SMEP composites had good shape memory performance and optimum thermal and mechanical performance.


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