scholarly journals Synthesis and Characterization of Healable Waterborne Polyurethanes with Cystamine Chain Extenders

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1492 ◽  
Author(s):  
Dae-Il Lee ◽  
Seung-Hyun Kim ◽  
Dai-Soo Lee
Keyword(s):  
Scratch Test ◽  
Chain Extender ◽  
Self Healing ◽  
Hot Press ◽  
High Mechanical Strength ◽  
Waterborne Polyurethanes ◽  
Before And After ◽  
Chain Extenders ◽  
A Chain

In this study, environmentally friendly, self-healing waterborne polyurethanes (WPUs) were prepared based on the disulfide metathesis reaction in cystamine. The cystamine acted as a chain extender in the WPU film, which showed a high mechanical strength of 19.1 MPa. The possibility of self-healing reaction was simultaneously modeled via liquid chromatography–mass spectrometry (LC-MS). WPU was confirmed to self-heal a surface crack thermally after a scratch test, and the efficiency was measured by comparing the mechanical properties before and after a cut-and-healing test. In addition, the disulfide-thiol exchange reaction was confirmed to occur in WPU with cystamine as a chain extender and 2-mercaptoethanol. Hot press tests confirmed the possibility of reprocessing the WPU. The WPU incorporating disulfide groups showed great potential as a smart self-healing material.

scholarly journals Preparation and Characterization of Isosorbide-Based Self-Healable Polyurethane Elastomers with Thermally Reversible Bonds

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1061 ◽  
Author(s):  
Han-Na Kim ◽  
Dae-Woo Lee ◽  
Hoon Ryu ◽  
Gwang-Seok Song ◽  
Dai-Soo Lee
Keyword(s):  
Elevated Temperatures ◽  
Phenyl Isocyanate ◽  
Chain Extender ◽  
The Self ◽  
Self Healing ◽  
Polyurethane Elastomers ◽  
Wide Range ◽  
Chain Extenders ◽  
Product Durability

Polyurethane (PU) is a versatile polymer used in a wide range of applications. Recently, imparting PU with self-healing properties has attracted much interest to improve the product durability. The self-healing mechanism conceivably occurs through the existence of dynamic reversible bonds over a specific temperature range. The present study investigates the self-healing properties of 1,4:3,6-dianhydrohexitol-based PUs prepared from a prepolymer of poly(tetra-methylene ether glycol) and 4,4′-methylenebis(phenyl isocyanate) with different chain extenders (isosorbide or isomannide). PU with the conventional chain extender 1,4-butanediol was prepared for comparison. The urethane bonds in 1,4:3,6-dianhydrohexitol-based PUs were thermally reversible (as confirmed by the generation of isocyanate peaks observed by Fourier transform infrared spectroscopy) at mildly elevated temperatures and the PUs showed good mechanical properties. Especially the isosorbide-based polyurethane showed potential self-healing ability under mild heat treatment, as observed in reprocessing tests. It is inferred that isosorbide, bio-based bicyclic diol, can be employed as an efficient chain extender of polyurethane prepolymers to improve self-healing properties of polyurethane elastomers via reversible features of the urethane bonds.

Synthesis and Characterization of Polyurethane/Clay Nanocomposites

2015 ◽  
Vol 1110 ◽  
pp. 73-76 ◽  
Author(s):  
Sau Leng Sin ◽  
Hong Yan ◽  
Jian Wei Xu
Keyword(s):  
Hydrogen Bonding ◽  
Chain Extender ◽  
Synthesis And Characterization ◽  
Clay Nanocomposites ◽  
Chain Extenders ◽  
A Chain

This paper describes synthesis of a series of polyurethane (PU)/clay nanocomposites by using two different chain extenders ethylenediamine (ED) and 1,3-diamino-2-propanol (DAP). By using DAP as a chain extender, PU/clay nanocomposites show not only the stronger inter-and intrachain interactions through hydrogen bonding, but also exhibit enhanced clay exfoliation as evidenced by the disappearance of clay diffraction at 2θ = 2.5-10°.

Polyurethane microcapsules for self-healing paint coatings

RSC Advances ◽  
2014 ◽  
Vol 4 (31) ◽  
pp. 16214-16223 ◽  
Author(s):  
Eunjoo Koh ◽  
Nam-Kyun Kim ◽  
Jihoon Shin ◽  
Young-Wun Kim
Keyword(s):  
Interfacial Polymerization ◽  
Chain Extender ◽  
Core Material ◽  
Self Healing ◽  
Paint Coatings ◽  
A Chain ◽  
Water Borne

Polyurethane microcapsules containing water-borne polyurethane (PU) paint as a core material for self-repairing protection coatings were successfully manufactured via interfacial polymerization of diol–diisocyanate prepolymer and 1,4-butanediol as a chain extender in an emulsion solution.

scholarly journals Thermally Self-Healing Graphene-Nanoplate/Polyurethane Nanocomposites via Diels–Alder Reaction through a One-Shot Process

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 434 ◽  
Author(s):  
Cho-Rong Oh ◽  
Sang-Hyub Lee ◽  
Jun-Hong Park ◽  
Dai-Soo Lee
Keyword(s):  
Molecular Design ◽  
Alder Reaction ◽  
Chain Extender ◽  
Diels Alder ◽  
Self Healing ◽  
Scanning Calorimetry ◽  
Diels Alder Reaction ◽  
A Chain ◽  
The Fourier Transform

Thermally self-healing graphene-nanoplate/polyurethane (GNP/PU) nanocomposites were prepared via a bulk in-situ Diels–Alder (DA) reaction. Graphene-nanoplate (GNP) was used as a reinforcement and crosslinking platform by a DA reaction with a furfuryl-based chain extender of polyurethane (PU). Results showed that a DA reaction occurred in GNP during the PU forming cure process. This procedure is simple and solvent free because of the absence of any independent surface modification process. Through the calculation of the interfacial tensions, the conditions of the bulk in-situ DA reaction were determined to ensure that GNP and the furfuryl group can react with each other at the interface during the curing process without a solvent. The prepared composites were characterized in terms of thermal, mechanical, and thermally self-healing properties via the DA reaction. In the PU capable of a DA reaction (DPU), characteristic peaks of DA and retro DA reactions were observed in the Fourier transform infrared (FT-IR) spectroscopy and endothermic peaks of retro DA reactions appeared in differential scanning calorimetry (DSC) thermograms. The DPU showed significantly enhanced physical properties and chemical resistance. The thermally self-healing capability was confirmed at 110 °C via the retro DA reactions. It is inferred that thermally self-healable crosslinked GNP/PU nanocomposites via DA reactions could be prepared in a simple bulk process through the molecular design of a chain extender for the in-situ reaction at the interface.

Waterborne polyurethanes: influence of chain extender in ftir spectra profiles

2012 ◽  
Vol 2 (2) ◽  
Author(s):  
Marcia Delpech ◽  
Gisele Miranda
Keyword(s):  
Soft Segment ◽  
Bond Formation ◽  
Chain Extender ◽  
Infrared Spectrometry ◽  
Absorption Bands ◽  
Hydrogen Bond Formation ◽  
Waterborne Polyurethanes ◽  
Soft Segments ◽  
Chain Extenders ◽  
Poly Propylene

AbstractNon-polluting systems based on waterborne polyurethanes (wPU) and poly(urethane-urea)s (wPUU) were synthesized employing poly(propylene glycol) (PPG), dimethylolpropionic acid (DMPA) and 4,4′-dicyclohexylmethane diisocyanate (HMDI) as monomers. In the formulations, the length and the proportion of the soft segments were varied. Three types of chain extenders were employed: ethylene glycol (EG), producing urethane linkages; and ethylenediamine (EDA) and hydrazine (HYD), forming urea linkages. Cast films obtained from wPU and wPUU, monomers and prepolymers were analyzed by Fourier transform infrared spectrometry (FTIR). The profile of carbonyl absorption bands obtained for the films showed some remarkable differences depending on the formulation. The bands were split into two parts, which were directly related to the tendency of hydrogen bond formation. The length of soft segment, the amount of rigid portions and the presence of urea linkages showed a marked influence in both intensity and frequency absorption of the bands.

scholarly journals Synthesis of self-healing waterborne polyurethanes containing sulphonate groups

RSC Advances ◽  
2017 ◽  
Vol 7 (33) ◽  
pp. 20093-20100 ◽  
Author(s):  
Ye Xiao ◽  
Huihua Huang ◽  
Xiaohong Peng
Keyword(s):  
Phase Separation ◽  
Waterborne Polyurethane ◽  
Chain Extender ◽  
Self Healing ◽  
Ionic Interaction ◽  
Aliphatic Diamine ◽  
Waterborne Polyurethanes

An self-healing waterborne polyurethane is synthesized using the aliphatic diamine sulphonate as a hydrophilic chain-extender. The ionic interaction between the sulphonate groups and the micro-phase separation morphology realize self-healing.

Morphological features of PU/PMMA hybrid latex prepared by Miniemulsion Polymerization

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Chien-Yu Li ◽  
Wen-Yen Chiu ◽  
Chia-Fen Lee
Keyword(s):  
Bisphenol A ◽  
Miniemulsion Polymerization ◽  
Chain Extender ◽  
Dibutyltin Dilaurate ◽  
Hybrid Particles ◽  
Transmission Electron ◽  
Chain Extenders ◽  
A Chain ◽  
Poly Propylene ◽  
Dynamic Lighting

AbstractPU/PMMA hybrid particles are synthesized by using the method of twostep miniemulsion polymerization. In the first step, PU prepolymer is synthesized by isophorone diisocyanates (IPDI) and poly(propylene glycol) (PPG) with methyl methacrylate (MMA) as a solvent. Then the oil phase, including the NCOterminated prepolymer, MMA, hexadecane (HD), a chain extender as 1,4- butanediol (BD) or bisphenol A (BisA), a cross-linking agent trimethylol propane (TMP), and a catalyst dibutyltin dilaurate (SnDBL) is dispersed in the water phase containing SDS. Then the mixtures form miniemulsion by ultrasonication. Two kinds of initiators, BPO and KPS, are applied for the polymerization of MMA. The influences of chain extenders, initiators and PU/MMA weight ratios on the morphology of PU/PMMA latex particles are investigated. Conversion of MMA is measured and discussed. Particle sizes are analyzed by dynamic lighting scattering (DLS) and transmission electron microscopy (TEM). The cross section morphology of the hybrid particles is also characterized by TEM. For BD/BPO and BD/KPS systems, when increasing the load of PU component, PU-rich phase is moved to the outside of hybrid particles. A core-shell structure can be observed. However, for BisA/KPS system, while using hydrophobic bisphenol A as chain extender of PU, the boundary of PMMA and PU phases is not clear. A more homogeneous structure of hybrid particles is obtained.

scholarly journals Effects of Diisocyanate Structure and Disulfide Chain Extender on Hard Segmental Packing and Self-Healing Property of Polyurea Elastomers

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 838 ◽  
Author(s):  
Ting Li ◽  
Tianze Zheng ◽  
Jiarui Han ◽  
Zhanli Liu ◽  
Zhao-Xia Guo ◽  
...  
Keyword(s):  
Disulfide Bonds ◽  
Aliphatic Amine ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Self Healing ◽  
Segmental Dynamics ◽  
Chain Mobility ◽  
Healing Property ◽  
Chain Extenders ◽  
Hard Segments

Four linear polyurea elastomers synthesized from two different diisocyanates, two different chain extenders and a common aliphatic amine-terminated polyether were used as models to investigate the effects of both diisocyanate structure and aromatic disulfide chain extender on hard segmental packing and self-healing ability. Both direct investigation on hard segments and indirect investigation on chain mobility and soft segmental dynamics were carried out to compare the levels of hard segmental packing, leading to agreed conclusions that correlated well with the self-healing abilities of the polyureas. Both diisocyanate structure and disulfide bonds had significant effects on hard segmental packing and self-healing property. Diisocyanate structure had more pronounced effect than disulfide bonds. Bulky alicyclic isophorone diisocyanate (IPDI) resulted in looser hard segmental packing than linear aliphatic hexamethylene diisocyanate (HDI), whereas a disulfide chain extender also promoted self-healing ability through loosening of hard segmental packing compared to its C-C counterpart. The polyurea synthesized from IPDI and the disulfide chain extender exhibited the best self-healing ability among the four polyureas because it had the highest chain mobility ascribed to the loosest hard segmental packing. Therefore, a combination of bulky alicyclic diisocyanate and disulfide chain extender is recommended for the design of self-healing polyurea elastomers.

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