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.

scholarly journals SYNTHESIS OF MICROCAPSULES FROM PREPOLYURETHANES

2018 ◽  
Vol 55 (1B) ◽  
pp. 138
Author(s):  
Ha La Thi Thai
Keyword(s):  
Interfacial Polymerization ◽  
Gum Arabic ◽  
Chain Extender ◽  
Toluene Diisocyanate ◽  
Agitation Rate ◽  
Self Healing ◽  
The Core ◽  
Core Content ◽  
Oil In Water ◽  
Healing Agent

Polyurethane (PU) microcapsules containing toluene diisocyanate (TDI) healing agent were synthesized by mixing PU with chain extender ethyleneglycol (EG) via interfacial polymerization of oil–in–water (gum arabic emulsifier). The morphology and size of the capsules greatly depend on a variety of factors including dispersion speed and emulsifier ratio. The preparation of PU prepolymer and microcapsulation of TDI are presented. The diameter of smooth spherical microcapsules ranged from 93, 160 and 239 µm are produced by varying the agitation rate from 800 rpm to 1200 rpm. The core content of microcapsules is influenced by the ratio of chlorobenzene (CB) solvent in oil phase. The microcapsules have about 40.5 wt% of core which are capable of application in self–healing coatings when using 20 wt% CB and 17.5 wt% emulsifer ratio.

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.

Effect of chain extender on microphase structure and performance of self‐healing polyurethane and poly(urethane‐urea)

2021 ◽  
pp. 51371
Author(s):  
Yulong Wang ◽  
Yaqiong Li ◽  
Maoyong He ◽  
Jingjing Bai ◽  
Bingxiao Liu ◽  
...  
Keyword(s):  
Chain Extender ◽  
Self Healing ◽  
And Performance

scholarly journals Preparation and Properties of Self-Healing and Self-Lubricating Epoxy Coatings with Polyurethane Microcapsules Containing Bifunctional Linseed Oil

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1578 ◽  
Author(s):  
Haijuan Yang ◽  
Qiufeng Mo ◽  
Weizhou Li ◽  
Fengmei Gu
Keyword(s):  
Interfacial Polymerization ◽  
Electrochemical Impedance ◽  
Linseed Oil ◽  
Salt Spray ◽  
Average Diameter ◽  
Organic Coating ◽  
Epoxy Coating ◽  
The Self ◽  
Self Healing ◽  
Pure Epoxy

An organic coating is commonly used to protect metal from corrosion, but it is prone to failure due to microcracks generated by internal stress and external mechanical action. The self-healing and self-lubricating achieved in the coating is novel, which allows an extension of life by providing resistance to damage and repair after damage. In this study, a new approach to microencapsulating bifunctional linseed oil with polyurethane shell by interfacial polymerization. Moreover, the self-healing and self-lubricating coatings with different concentrations of microcapsules were developed. The well-dispersed microcapsules showed a regular spherical morphology with an average diameter of ~64.9 μm and a core content of 74.0 wt.%. The results of the salt spray test demonstrated that coatings containing microcapsules still possess anticorrosion, which is improved with the increase of microcapsules content, after being scratched. The results of electrochemical impedance spectroscopy showed a |Z|f=0.01Hz value of 104 Ω·cm2 for pure epoxy coating after being immersed for 3 days, whereas the coating with 20 wt.% microcapsules was the highest, 1010 Ω·cm2. The results of friction wear showed that the tribological performance of the coating was enhanced greatly as microcapsule concentration reached 10 wt.% or more, which showed a 86.8% or more reduction in the friction coefficient compared to the pure epoxy coating. These results indicated that the coatings containing microcapsules exhibited excellent self-healing and self-lubricating properties, which are positively correlated with microcapsules content.

Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites

2014 ◽  
pp. n/a-n/a ◽  
Author(s):  
Weihua Fan ◽  
Yue Zhao ◽  
Aijing Zhang ◽  
Yukun Liu ◽  
Yanxia Cao ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Lactic Acid ◽  
Chain Extender ◽  
Poly Lactic Acid ◽  
A Chain

scholarly journals Synthesis and Properties of Waterborne Polyurethane (WBPU)/Modified Lignin Amine (MLA) Adhesive: A Promising Adhesive Material

2016 ◽  
Author(s):  
Mohammad Mizanur Rahman ◽  
Md. Hasan Zahir ◽  
Han Do Kim
Keyword(s):  
Adhesive Strength ◽  
Weather Conditions ◽  
Waterborne Polyurethane ◽  
Chain Extender ◽  
Mixing Process ◽  
Adhesive Material ◽  
Lignin Amine ◽  
A Chain ◽  
Modified Lignin ◽  
Adhesive Materials

A series of waterborne polyurethane (WBPU)/modified lignin amine (MLA) adhesives was prepared using modified lignin amine (MLA) as a chain extender by a prepolymer mixing process. A successful Mannich reaction was achieved during the synthesis of MLA by reacting lignin with bis(3-aminopropyl)amine. Higher tensile strength, Young’s modulus and thermal stability were recorded for WBPU/MLA adhesives with higher MLA contents. The WBPU/MLA adhesive materials were used to coat PVC substrates. The adhesive strength increased with increasing MLA content. More importantly, the MLA also enhanced the WBPU/MLA coating in terms of adhesive strength at moderately high temperatures as well as under natural weather exposed conditions. The adhesive strength was essentially unaffected with 6.48 mole% MLA in the WBPU/MLA coating after exposure to natural weather conditions for 180 days.

Modification of nylon-6 with poly (m-phenylene isophthalamide) via MDI as a chain extender

1993 ◽  
Vol 28 (18) ◽  
pp. 4862-4867 ◽  
Author(s):  
Ming-Fung Lin ◽  
Yao-Chi Shu
Keyword(s):  
Nylon 6 ◽  
Chain Extender ◽  
A Chain

Rheology of Thermoplastic Polyurethanes

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Rheological Behavior ◽  
Thermoplastic Polyurethane ◽  
Complete Characterization ◽  
Chain Extender ◽  
Reaction Sequence ◽  
Molecular Weights ◽  
Soft Segments ◽  
Hard Segments ◽  
A Chain ◽  
Long Chain

Thermoplastic polyurethane (TPU) has received considerable attention from both the scientific and industrial communities (Hepburn 1982; Oertel 1985; Saunders and Frish 1962). Applications for TPUs include automotive exterior body panels, medical implants such as the artificial heart, membranes, ski boots, and flexible tubing. Figure 10.1 gives a schematic that shows the architecture of TPU, consisting of hard and soft segments. Hard segments, which form a crystalline phase at service temperature, are composed of diisocyanate and short-chain diols as a chain extender, while soft segments, which control low-temperature properties, are composed of difunctional long-chain polydiols with molecular weights ranging from 500 to 5000. The soft segments form a flexible matrix between the hard domains. TPUs are synthesized by reacting difunctional long-chain diol with diisocyanate to form a prepolymer, which is then extended by a chain extender via one of two routes: (1) by a dihydric glycol chain extender or (2) by a diamine chain extender. The most commonly used diisocyanate is 4,4’-diphenylmethane diisocyanate (MDI), which reacts with a difunctional polyol forming soft segments, such as poly(tetramethylene adipate) (PTMA) or poly(oxytetramethylene) (POTM), to produce TPU, in which 1,4-butanediol (BDO) is used as a chain extender. There are two methods widely used to produce TPU: (1) one-shot reaction sequence and (2) two-stage reaction sequence. The reaction sequences for both methods are well documented in the literature (Hepburn 1982). It should be mentioned that MDI/BDO/PTMA produces ester-based TPU. One can also produce ether-based TPU when MDI reacts with POTM using BDO as a chain extender. TPUs are often referred to as “multiblock copolymers.” In order to have a better understanding of the rheological behavior of TPUs, one must first understand the relationships between the chemical structure and the morphology; thus, a complete characterization of the materials must be conducted. The rheological behavior of TPU depends, among many factors, on (1) the composition of the soft and hard segments, (2) the lengths of the soft and hard segments and the sequence length distribution, (3) anomalous linkages (branching, cross-linking), and (4) molecular weight.

scholarly journals Preparation and Characterization of Ethylenediamine-Polyurea Microcapsule Epoxy Self-Healing Coating

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 326 ◽  
Author(s):  
Yanxuan Ma ◽  
Yingrui Zhang ◽  
Jiatong Liu ◽  
Yi Sun ◽  
Yajie Ge ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Spherical Shape ◽  
Core Material ◽  
Self Healing ◽  
Characterization Methods ◽  
Chemical Structures ◽  
Size And Morphology ◽  
Eis Measurements ◽  
External Corrosion ◽  
The Fourier Transform

Polyurea microcapsules with Ethylenediamine (EDA) as the core material were synthesized. A set of characterization methods, including optical and scanning electron microscopy (OM and SEM), the Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were used to confirm the microcapsule morphology and chemical structures. The influence of emulsifier content and stirring rate on size and morphology of the microcapsules was investigated, and the self-healing performance of EDA-Polyurea microcapsule/epoxy coatings was evaluated by electrochemical impedance spectroscopy (EIS) measurements. The results showed that the microcapsules obtained had good spherical shape with a mean diameter of 0.54–0.70 μm. Compared with pure core material, the microcapsule showed excellent thermostability, and the content of core materials was up to 56.00 wt%. The epoxy coating with 5.0 wt% EDA-Polyurea microcapsules achieved average corrosion resistance efficiencies of 90.00%, significantly enhancing the capability of the scratched coating to resist external corrosion.

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