Autonomous self-healing polyisoprene elastomers with high modulus and good toughness based on the synergy of dynamic ionic crosslinks and highly disordered crystals

2020 ◽  
Vol 11 (41) ◽  
pp. 6549-6558
Author(s):  
Yohei Miwa ◽  
Mayu Yamada ◽  
Yu Shinke ◽  
Shoichi Kutsumizu
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Self Healing ◽  
High Modulus ◽  
Disordered Crystals ◽  
Ionic Crosslinks

We designed a novel polyisoprene elastomer with high mechanical properties and autonomous self-healing capability at room temperature facilitated by the coexistence of dynamic ionic crosslinks and crystalline components that slowly reassembled.

scholarly journals Recyclable Self-Healing Polyurethane Cross-Linked by Alkyl Diselenide with Enhanced Mechanical Properties

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 773 ◽  
Author(s):  
Yuqing Qian ◽  
Xiaowei An ◽  
Xiaofei Huang ◽  
Xiangqiang Pan ◽  
Jian Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Amide Bond ◽  
Self Healing ◽  
Healing Efficiency ◽  
Polyurethane Networks ◽  
Combined Action ◽  
Cross Linker ◽  
Dynamic Structures ◽  
External Interventions

Dynamic structures containing polymers can behave as thermosets at room temperature while maintaining good mechanical properties, showing good reprocessability, repairability, and recyclability. In this work, alkyl diselenide is effectively used as a dynamic cross-linker for the design of self-healing poly(urea–urethane) elastomers, which show quantitative healing efficiency at room temperature, without the need for any catalysts or external interventions. Due to the combined action of the urea bond and amide bond, the material has better mechanical properties. We also compared the self-healing effect of alkyl diselenide-based polyurethanes and alkyl disulfide-based polyurethanes. The alkyl diselenide has been incorporated into polyurethane networks using a para-substituted amine diphenyl alkyl diselenide. The resulting materials not only exhibit faster self-healing properties than the corresponding disulfide-based materials, but also show the ability to be processed at temperatures as low as 60 °C.

Self-Healing Magnetorheological Elastomer for Vibration Damping

2020 ◽  
Vol 982 ◽  
pp. 3-8
Author(s):  
Raa Khimi Shuib ◽  
Nuur Laila Najwa Thajudin ◽  
Mohd Hafiz Zainol
Keyword(s):  
Natural Rubber ◽  
Room Temperature ◽  
Graft Polymerization ◽  
Mechanical Analysis ◽  
Self Healing ◽  
Magnetorheological Elastomers ◽  
Nickel Zinc ◽  
Fracture Area ◽  
Zinc Thiolate ◽  
Ionic Crosslinks

In this work, magnetorheological elastomers (MRE) based on nickel zinc ferrite and natural rubber were prepared. Self-healing capability was employed to the MRE by peroxide induced graft polymerization between zinc thiolate and natural rubber to produce reversible ionic crosslinks that can recover the properties of the fracture materials. Evidence that reversible ionic crosslinks occurred was determined by tensile test of original and healed sample. The results revealed that the tensile strength of the MRE recovered 56% in a minute and almost 100% in 10 minutes at room temperature. The morphology of the fractured surface also showed the fracture area was recovered after the healing processed. The dynamic mechanical analysis of the MREs under cyclic loading were also examined with parallel plate rheometer.

scholarly journals A novel kind of room temperature self-healing poly(urethane-urea) with robust mechanical strength based on aromatic disulfide

2021 ◽  
Vol 28 (4) ◽  
Author(s):  
Jin He ◽  
Fangfang Song ◽  
Xiong Li ◽  
Liyi Chen ◽  
Xingyu Gong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
Room Temperature ◽  
Toluene Diisocyanate ◽  
Self Healing ◽  
Isophorone Diisocyanate ◽  
Elongation At Break ◽  
Strength Based ◽  
Hard Segments ◽  
Poly Propylene

AbstractAn innovative poly(urethane-urea) elastomer, which exhibited excellent stretchability, thermal stability and autonomous self-healing abilities, was synthesized from the commercially available poly(propylene glycol) (PPG), isophorone diisocyanate (IPDI), 2,4 / 2,6-toluene diisocyanate (80: 20, w / w) (TDI-80) and bis (2-aminophenyl) disulfide (DSDA). This aromatic disulfide containing poly(urethane-urea) (ss-PUs) achieved both rapid room temperature self-healing abilities and robust mechanical strength (the ultimate tensile strength was up to 4.20 ± 0.10 MPa and elongation at break was up to 954 ± 35.6%), through facile metathesis of the aromatic disulfides which embedded in hard segments. After the ss-PUs was cut into two-halves and reconnected, the mechanical properties could recover to ~ 90% of those of the original samples within 12 h at room temperature without extra self-healing agents or any change of environmental conditions.

scholarly journals Dynamic Covalent Bonds of Si-OR and Si-OSi Enabled A Stiff Polymer to Heal and Recycle at Room Temperature

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2680
Author(s):  
Ping Fan ◽  
Can Xue ◽  
Xiantai Zhou ◽  
Zujin Yang ◽  
Hongbing Ji
Keyword(s):  
Mechanical Properties ◽  
Small Molecule ◽  
Potential Application ◽  
Room Temperature ◽  
The Self ◽  
Self Healing ◽  
Bending Properties ◽  
Covalent Bonds ◽  
Model Experiments ◽  
Molecule Model

As stiff polymers are difficult to self-heal, the balance between polymers’ self-healing ability and mechanical properties is always a big challenge. Herein, we have developed a novel healable stiff polymer based on the Si-OR and Si-OSi dynamic covalent bonds. The self-healing mechanism was tested and proved by the small molecule model experiments and the contrast experiments of polymers. This polymer possesses excellent tensile, bending properties as well as room temperature self-healing abilities. Moreover, due to the sticky and shapeable properties under wetting conditions, the polymer could be used as an adhesive. Besides, even after four cycles of recycling, the polymer maintains its original properties, which meets the requirements of recyclable materials. It was demonstrated that the polymer exhibits potential application in some fields, such as recyclable materials and healable adhesives.

Synergy between dynamic covalent boronic ester and boron–nitrogen coordination: strategy for self-healing polyurethane elastomers at room temperature with unprecedented mechanical properties

2021 ◽  
Author(s):  
Kai Song ◽  
Wujin Ye ◽  
Xingchen Gao ◽  
Huagao Fang ◽  
Yaqiong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Interactions ◽  
Room Temperature ◽  
Self Healing ◽  
Polyurethane Elastomers ◽  
Coordination Strategy ◽  
Boronic Ester ◽  
Healing Efficiency ◽  
Boron Nitrogen

Boron–nitrogen coordination in polyurethane elastomers enhances the dynamics of the boronic ester while introduces inter- and intra-molecular interactions, leading to mechanical robustness and excellent self-healing efficiency simultaneously.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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