scholarly journals Recyclable Shape-Memory Waterborne Polyurethane Films Based on Perylene Bisimide Modified Polycaprolactone Diol

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1755
Author(s):  
Kang Wei ◽  
Haitao Zhang ◽  
Jianbo Qu ◽  
Jianyong Wang ◽  
Yang Bai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Shape Memory ◽  
Storage Stability ◽  
Microphase Separation ◽  
Soft Segment ◽  
Waterborne Polyurethane ◽  
Significant Degree ◽  
Perylene Bisimide ◽  
Good Shape

Currently, much attention is given to the functionality and recyclability of waterborne polyurethane (WPU). Herein, ε-caprolactone was used as a chain extender for grafting onto perylene bisimide (PBI) and 1,4-butanediol (BDO) via ring-opening reactions to obtain PBI-PCL and BDO- PCL. Then, two kinds of WPU, namely PBI-WPU (PWPU) and BDO-WPU (BWPU), were fabricated using PBI-PCL/polytetrahydrofuran ether glycol (PTMG) and BDO-PCL/PTMG, respectively, as mixed soft segments. The properties and appearance of PWPU and BWPU emulsions were analyzed in terms of particle size, zeta potential and TEM images, and the results showed that PWPU emulsions had uniform particle size distribution and decent storage stability. AFM and DMA results revealed that PWPU films possessed a more significant degree of microphase separation and a higher glass transition temperature (Tg) than BWPU films. The PWPU films displayed good shape-memory and mechanical properties, with tensile strength up to 58.25 MPa and elongation at break up to 1241.36%. TGA analysis indicated that PWPU films had better thermal stability than BWPU films. More importantly, the PWPU films could be dissolved in a mixed solvent of acetone/ethanol (v/v = 2:1) at room temperature. The dissolved PWPU could be dispersed in deionized water to prepare waterborne polyurethane again. After the recycling process was repeated three times, the recycled PWPU emulsion still exhibited good storage stability. The recycled PWPU films maintained their original thermal and mechanical properties. Comparing the properties of BWPU and PWPU showed that the soft segment structure had important influence on waterborne polyurethane performance. Therefore, PWPU may have great potential applications in making recycling and shape-memory coating or paint.

Pseudoelasticity of Cu-13.8Al-Ni Alloys Containing V and Nb

2008 ◽  
Vol 59 ◽  
pp. 101-107 ◽  
Author(s):  
Rodinei Medeiros Gomes ◽  
Ana Cris R. Veloso ◽  
V.T.L. Buono ◽  
Severino Jackson Guedes de Lima ◽  
Tadeu Antonio de Azevedo Melo
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Shape Recovery ◽  
Cold Water ◽  
Low Cost ◽  
Tensile Tests ◽  
Grain Refiner ◽  
Good Shape ◽  
Potential Applications ◽  
Superelastic Behavior

Polycrystalline copper-based shape memory alloys have been of particular interest in relation to Ni-Ti because of their low cost and good shape memory effect. Nevertheless the absence of a pronounced pseudoelasticity effect restricts the number of potential applications. In this work, the influence of Nb and V on the microstructure and the mechanical properties was investigated. Samples of Cu-13.8 Al-Ni containing V and Nb alloy were prepared by induction and solution treated at 850°C and then further quenched into cold water. The addition of Nb and V promotes the formation of precipitates which act as grain refiner and subsequently improve the mechanical properties. The tensile tests were performed at temperatures slightly inferior to Mf and superior to Af, to investigate the shape recovery and pseudoelasticity, respectively. Based on the analyses of the Cu-13,8Al-2Ni-1Nb (wt%) alloy was detected rupture strains greater than 14%, besides observation of the superelasticity of these alloys and quantification of this property by means of cycling, from 0 to strains between 1 and 7%. The studies performed on alloy Cu-13.8Al- 3,5Ni-1V (wt%) made it possible to determine rupture strains in the order of 3% and its superelastic behavior through cycling for deformations between 1 and 3%.

Effect of Block Molecular Weight on the Mechanical Properties of PA1010-b-PEG Segmented Block Copolymers

2012 ◽  
Vol 512-515 ◽  
pp. 2127-2130
Author(s):  
Li Huo ◽  
Cai Xia Dong
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Microphase Separation ◽  
Soft Segment ◽  
Mechanical Measurements ◽  
Wide Range ◽  
Hard Block ◽  
Higher Temperature ◽  
Hard Segments

The mechanical properties were investigated of a series of PA-PEG thermalplastic elastomer based on PA1010 and polytetramethylene glycol (PEG) with varying hard and soft segment content. Dynamic mechanical measurements of these polymers have carried out over a wide range of temperatures. The block copolymers exhibit three peaks, designated as α, β and γ in the tanδ-temperature curve. The α transition shifts to higher temperature with increasing hard block molecular weight. However, at a constant hard molecular weight, the α transition shifts to higher temperature and the damping increases on increasing the soft segment molecular weight. DMA results show that the block copolymers exhibit a microphase separation structure and both soft and hard segments were found to be crystallizable. The degree of phase separation increases with increasing hard block molecular weight.

Study on Polyurethane Dispersions with PES/PPG and High-Solid Content

2013 ◽  
Vol 864-867 ◽  
pp. 588-591 ◽  
Author(s):  
Xiao Li Wei ◽  
Fa Xing Zhang
Keyword(s):  
Particle Size ◽  
Shape Memory ◽  
Solid Content ◽  
Plastic Behavior ◽  
Mass Ratio ◽  
High Solid Content ◽  
High Solid ◽  
Shape Memory Behavior ◽  
Good Shape ◽  
Polyurethane Dispersions

A series of novel stable and high-solid-content polyurethane were prepared by self-emulsification,use PES and PPG as mixed soft segments.Influence of APAETMS content and mole ratio of PES/PPG on properties of polyurethane dispersions and films were analyzed .Results show that: the cross-linked complex were multivariate distribution in particle size. With an increase of the mass ratio of PES and PPG and content of APAETMS average particles diameter of polyurethane dispersions became bigger , poly-dispersion became wider., solid content of dispersions decrease.. It is also noticed that the high-solid-content dispersions exhibit a pseudo-plastic behavior, when the mass ratio of PES and PPG is 1:3 and content of APAETMS is 1%, the solid content of dispersions is up to 55%. The film also has a good shape memory behavior.

Fabrication and Surface Modification of Porous Nano-Structured NiTi Orthopedic Scaffolds for Bone Implants

2009 ◽  
Vol 1181 ◽  
Author(s):  
Shuilin Wu ◽  
Xiangmei Liu ◽  
Paul K Chu ◽  
Tao Hu ◽  
Kelvin Wai Kwok Yeung ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Shape Memory ◽  
Porous Ceramics ◽  
Bone Implants ◽  
Nickel Ion ◽  
Niti Alloys ◽  
Porous Niti ◽  
Surface Areas ◽  
Good Shape

AbstractNear-equiatomic porous nickel-titanium shape memory alloys (NiTi SMAs) are becoming one of the most promising biomaterials in bone implants because of their unique advantages over currently used biomaterials. For example, they have good mechanical properties and lower Young�s modulus relative to dense NiTi, Ti, and Ti-based alloys. Porous NiTi SMAs are relatively easy to machine compared to porous ceramics such as hydroxyapatite and calcium phosphate that tend to exhibit brittle failure. The porous structure with interconnecting open pores can also allow tissue in-growth and favors bone osseointegration. In addition, porous NiTi alloys remain exhibiting good shape memory effect (SME) and superelasticity (SE) similar to dense NiTi alloys. To optimize porous NiTi SMAs in bone implant applications, the current research focuses on the fabrication methods and surface modification techniques in order to obtain adjustable bone-like structures with good mechanical properties, excellent superelasticity, as well as bioactive passivation on the entire exposed surface areas to block nickel ion leaching and enhance the surface biological activity. This invited paper describes progress in the fabrication of the porous materials and our recent work on surface nanorization of porous NiTi scaffolds in bone grafts applications.

scholarly journals Polyurethane cationomers containing fluorinated soft segments with hydrophobic properties

2021 ◽  
Author(s):  
Piotr Król ◽  
Kinga Pielichowska ◽  
Bożena Król ◽  
Katarzyna Nowicka ◽  
Małgorzata Walczak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hard Segment ◽  
Molar Mass ◽  
Microphase Separation ◽  
Waterborne Polyurethane ◽  
Thermal And Mechanical Properties ◽  
Nmr Analysis ◽  
Hydrophobic Properties ◽  
Average Molar Mass ◽  
Soft Segments

AbstractThe synthesis of ecological waterborne polyurethane cationomers containing fluorinated polyol (0–20 wt.%) was successfully performed. FTIR and NMR analysis results confirmed the structure of the obtained polyurethane cationomers and incorporation of fluorinated component into the polyurethane chains. Average molar mass and phase structure of the obtained PU thin films were determined based on GPC, FTIR, WAXD and SEM-EDX results. The obtained cationomers have linear structures with clearly visible microphase separation of soft and hard segment domains; the presence of fluorinated polyol changes the strength of hydrogen bonds and in consequence degree of phase separation. The activation energy of glass transition was calculated based on multi-frequency DSC data. It has been shown that the presence of soft fluorinated segments in the cationomer structure strongly influences the hydrophobic, thermal and mechanical properties of the obtained films.

scholarly journals The Crystallisation, Microphase Separation and Mechanical Properties of the Mixture of Ether-Based TPU with Different Ester-Based TPUs

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3475
Author(s):  
Yu-Hui Que ◽  
Ying Shi ◽  
Li-Zhi Liu ◽  
Yuan-Xia Wang ◽  
Chen-Chen Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Level ◽  
Microphase Separation ◽  
Soft Segment ◽  
Phase Region ◽  
The Other ◽  
Elongation At Break ◽  
Similar Chemical ◽  
Aggregation Structure ◽  
The Difference

The difference in compatibility at the molecular level can lead to a change of microphase separation structure of thermoplastic polyurethanes blend systems, which will improve their thermal and mechanical properties. In this study, TDI-polyester based TPU was blended with MDI-polyether-based TPU and MDI-polyester based TPU, with different ratios. In the blend system, the obvious reduction of the melting temperature of the high-temperature TDI-polyester based TPU component indicates its hard segments can be mutually integrated with the other component. For TDI-polyester based TPU/MDI-polyether based TPU blends, their similar hard segment ratio and similar chemical structure of the soft segment give the molecular chains of the two components better compatibility. The aggregation structure of the two kinds of chains can rearrange at the molecular level which makes the hard domains mutually integrate to form a new phase separation structure with larger phase region distance. As a result, the yield strength of this blend increased by almost 143% when the elongation at break was only reduced by 12%. In contrast, the other group of blends still partly maintain their respective micro domains, forming a weak interface and leading to a decreased of elongation at break.

Mechanical Properties of Ti-Nb Biomedical Shape Memory Alloys Containing 13- and 14-Group Elements

2005 ◽  
Vol 475-479 ◽  
pp. 2329-2332 ◽  
Author(s):  
Hideki Hosoda ◽  
Yusuke Fukui ◽  
Tomonari Inamura ◽  
Kenji Wakashima ◽  
Shuichi Miyazaki
Keyword(s):  
Mechanical Properties ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Room Temperature ◽  
Solution Hardening ◽  
Good Shape ◽  
Solution Treated ◽  
Beta Titanium ◽  
Shape Memory Properties ◽  
Elongation To Failure

In order to replace Ti-Ni shape memory alloys, new biomedical shape memory alloys have been developed which are composed of beta titanium and nontoxic elements only. In this paper, experimental results of mechanical and shape memory properties are reported for the Ni-free Ti-18mol%Nb shape memory alloys containing 3mol% of 13-group and 14-group ternary elements in the periodic table. The ternary elements selected are Al, Ga, In, Ge and Sn. It was found that the solution treated alloys exhibit good shape memory effect but almost no pseudoelasticity at room temperature. Ultimate tensile strength and elongation to failure at room temperature are ranged from 250 to 710MPa and from 13 to 21%, respectively, depending on the kind of ternary elements. Effect of solution hardening on strength is discussed.

Study on the Modification of Waterborne Polyurethane by Tung Oil Anhydride-Ester Polyol

2015 ◽  
Vol 1088 ◽  
pp. 460-466 ◽  
Author(s):  
Jin Hua Zhou ◽  
Jing Yang ◽  
Wen Jie Ma ◽  
Ni Li ◽  
Han Zhou Sun
Keyword(s):  
Particle Size ◽  
Tensile Test ◽  
Soft Segment ◽  
Waterborne Polyurethane ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Tung Oil ◽  
Weight Content ◽  
Emulsion Film ◽  
Emulsion Particle

Waterborne polyurethane (WPU) emulsions were prepared with Tung oil anhydride-ester polyol (TOAEP) as modifier via the acetone process. The structure, morphology, emulsion particle size, thermal property and mechanical property of the Modified WPU were investigated by FT-IR, SEM, Laser particle size analysis, TG and tensile test, respectively. The experimental results show that the modified WPU emulsion particle size increases along with the growth of weight content of TOAEP. Compared with the unmodified WPU emulsion film, water and toluene absorption of the modified WPU emulsion film have decreased significantly, indicating that water and solvent resistance are remarkably improved after the modification. Tensile test shows that the tensile strength of the modified WPU emulsion film increases with the content of TOAEP while the reverse is true for the elongation at break. The characteristic thermo-decomposition temperatures of WPU have been increased notably after modification by the introduction of TOAEP which indicates that the heat resistance has been improved after modification. Morphology analysis shows that the soft segment phase and hard segment phase in the WPU are more compatible after modification.

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