Transformation of a Kurome natural lacquer film from glassy to rubbery polymer by the presence of moisture

Sato, Shuichi; Ido, Ryohei; Ose, Takamasa; Takahashi, Yoshihiro; Kanehashi, Shinji; Ishimura, Takahisa; Honda, Takayuki; Miyakoshi, Tetsuo; Nagai, Kazukiyo

doi:10.1016/j.porgcoat.2016.12.003

Cited by 12 publications

(8 citation statements)

References 14 publications

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“…As can be seen, wide-angle X-ray diffraction showed a very broad peak at 19.9°o wing to the presence of amorphous structure domains in the UFP films which was characteristic of UFP. 25 The XRD pattern of the GO/UFP sample was similar to that of the UFP, and no obvious characteristic diffraction peaks of GO were observed because of its low loading content and weak crystallization. Compared with the GO/UFP sample, the diffraction peaks at 19.9°of the MGO/UFP samples were sharp and intense, indicating their more highly crystalline nature than the GO/UFP sample.…”

Section: Phase Composition Of the Mgo/ufp Composite Coatingsmentioning

confidence: 83%

Preparation, characterization, and properties of graphene oxide/urushiol-formaldehyde polymer composite coating

Zhang

Wei

et al. 2018

J Coat Technol Res

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Graphene oxide (GO) was modified by 3methacryloxypropyltrimethoxysilane (MPS) to obtain modified graphene oxide (MGO). MGO was dispersed in urushiol-formaldehyde polymer by mechanical mixing and ultrasonic dispersion, and MGO/urushiolformaldehyde polymer (UFP) coatings with different MGO contents were fabricated. The microstructure, physico-mechanical properties, and electrochemical properties of the MGO/UFP composite coatings were investigated. The results indicated that the hardness, adhesion, and corrosion resistance of the MGO/UFP composite coatings were obviously enhanced compared with the pure UFP coatings. The hardness and the adhesion grade of the MGO/UFP composite coatings with 3.5 wt% MGO (GO, 1.5 wt%, and MPS, 2.0 wt%) reached 6H and 2, respectively. Additionally, GO connected with MPS by chemical bond and the well-dispersed MGO in UFP could significantly enhance the anticorrosion performance of the UFP coatings, which could result from bending the diffusion pathway of penetrant species in the UFP coating matrix.

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Section: Phase Composition Of the Mgo/ufp Composite Coatingsmentioning

confidence: 83%

Preparation, characterization, and properties of graphene oxide/urushiol-formaldehyde polymer composite coating

Zhang

Wei

et al. 2018

J Coat Technol Res

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“…This is attributed to the excellent durability of the urushiol lacquer matrix without degradation of the material over time. Although further investigation is required to elucidate the origin of this enhancement, we speculate that the slow and continuous auto-oxidative reaction of the unreacted urushiol by oxygen molecules which was permeated into the film proceeded, which result in increment of cross-linking density of the binder matrix of the UL–Ag film …”

Section: Results and Discussionmentioning

confidence: 99%

“…Although further investigation is required to elucidate the origin of this enhancement, we speculate that the slow and continuous autooxidative reaction of the unreacted urushiol by oxygen molecules which was permeated into the film proceeded, which result in increment of cross-linking density of the binder matrix of the UL−Ag film. 53 The long-term stability of the conductive films prepared from the UL−Ag paste and the Ep−Ag paste was tested under the harsh conditions of high temperature of 85 °C and high humidity of 85% RH, which is referred to as the 85/85 test. Figure 5f shows the variations in color and resistance of the conductive films according to the exposure time to the 85/85 test conditions.…”

Section: Resultsmentioning

confidence: 99%

Ecofriendly Catechol Lipid Bioresin for Low-Temperature Processed Electrode Patterns with Strong Durability

Lee

Han

Hahn

et al. 2020

ACS Appl. Mater. Interfaces

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We demonstrated catechol lipid-based bioresin, which is collected from lacquer trees, to produce conductive pastes that can be processed at low temperatures, which are highly adhesive and multidurable. Our conductive paste, which consists of catechol lipid-based urushiol resin and a multimodal mixture of silver fillers, exhibited stable dispersion with shear thinning properties. The urushiol lacquer induced spontaneous reduction of silver salt at the surface of the silver fillers, thereby contributing to lower the contact resistance between conductive fillers in the electrical conduction. Furthermore, the directional volume shrinkage of the urushiol lacquer matrix in a cross-linking reaction resulted in a highly ordered microstructure of the silver fillers with layer-by-layer stacking of the silver flakes. This structure contributed to the improvement of the electrical contact between fillers as well as excellent mechanical hardness, anti-scratch capability, and the long-term environmental stability of the conductive films. Conductive films based on the silver paste with urushiol lacquer exhibited low electrical resistivity below 4.4 × 10–5 Ω cm, 5B-class strong adhesion strength, and high hardness exceeding 200 MPa. Finally, we demonstrated the facile room-temperature processability and screen printability of the UL–Ag paste by fabricating a printed antenna and three-dimensional (3D) electrode assembly based on a plastic 3D block.

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“…Additionally, plasticizers help enhance the film’s adhesion to the tablet’s surface. However, water uptake can be thought of as having “dissolved” into the amorphous structure and acts as a plasticizer by promoting the glass-to-rubber state transition of the polymeric system [33,34]. In the presence of moisture, unplasticized films can also cause significant changes in the mechanical properties of the film.…”

Section: Formulations Of Moisture Barrier Coatingmentioning

confidence: 99%

An Update of Moisture Barrier Coating for Drug Delivery

Yang

Feng

et al. 2019

Pharmaceutics

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Drug hydrolytic degradation, caused by atmospheric and inherent humidity, significantly reduces the therapeutic effect of pharmaceutical solid dosages. Moisture barrier film coating is one of the most appropriate and effective approaches to protect the active pharmaceutical ingredients (API) from hydrolytic degradation during the manufacturing process and storage. Coating formulation design and process control are the two most commonly used strategies to reduce water vapor permeability to achieve the moisture barrier function. The principles of formulation development include designing a coating formulation with non-hygroscopic/low water activity excipients, and formulating the film-forming polymers with the least amount of inherent moisture. The coating process involves spraying organic or aqueous coating solutions made of natural or synthetic polymers onto the surface of the dosage cores in a drum or a fluid bed coater. However, the aqueous coating process needs to be carefully controlled to prevent hydrolytic degradation of the drug due to the presence of water during the coating process. Recently, different strategies have been designed and developed to effectively decrease water vapor permeability and improve the moisture barrier function of the film. Those strategies include newly designed coating formulations containing polymers with optimized functionality of moisture barrier, and newly developed dry coating processes that eliminate the usage of organic solvent and water, and could potentially replace the current solvent and aqueous coatings. This review aims to summarize the recent advances and updates in moisture barrier coatings.

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Transformation of a Kurome natural lacquer film from glassy to rubbery polymer by the presence of moisture

Cited by 12 publications

References 14 publications

Preparation, characterization, and properties of graphene oxide/urushiol-formaldehyde polymer composite coating

Preparation, characterization, and properties of graphene oxide/urushiol-formaldehyde polymer composite coating

Ecofriendly Catechol Lipid Bioresin for Low-Temperature Processed Electrode Patterns with Strong Durability

An Update of Moisture Barrier Coating for Drug Delivery

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