Preparation and Properties of Chinese Lacquer Modified by Methylolureas

In this study,different molar of methylolureas(MMU)were used to improve the properties and drying speed of the raw lacquer(RL).The drying time,gloss,pencil hardness and impact resistance of the lacquer film were tested.The thermal behaviors and chemical structures of the lacquer membrane were also discussed by thermal gravimetric analysis(TGA),fourier infrared spectrometer(FT-IR)and nuclear magnetic resonance(NMR)analysis,respectively.The results demonstrated that lower molar ratio MMU can significantly improve the properties of lacquer.The TGA analysis showed that the modified lacquer had high thermal stability than that of the control.The FT-IR and 13C NMR analysis revealed that the structures of the modified lacquer were significantly improved by cross-linking with the hydroxymethyl groups and methylene methyl ethers of MMU.In addition,through scanning electron microscopy(SEM)characterization,it was found that the introduction of MMU can effectively improve the surface smoothness of the lacquer film.

Surface Activation of Plane and Curved Automotive Polymer Surfaces by Using a Fittable Multi-Pin DBD Plasma Source

In this work, surface activation of automotive polymers using atmospheric pressure plasmas was investigated. The aim was to increase the polar fraction of the surface energy of both plane and convex polymer devices with a radius in the range of 30 mm. For this purpose, a fittable low temperature atmospheric pressure plasma source based on capacitively coupled multi-pin electrodes was set up and applied. Each single electrode generates a treatment spot of approximately 2 cm2 with a tunable power density of up to 1.4 W/cm2. The surface energy was evaluated by contact angle measurements. After treatment at a low energy density of 1.01 J/cm2, the polar fraction of the surface energy of the investigated polymers was increased by a factor of 3.3 to 132, depending on the polymer materials. It was shown that by applying the presented fittable plasma source, this effect is independent of the surface radius of the polymer sample.

Physicochemical properties of lacquer berries and decolorization of lacquer wax by physical adsorption and UV irradiation

Physicochemical properties of No.1 - No.6 lacquer berries were investigated from different origins. The Japan Showafuku (No.1) was the best cultivar of Rhus succedaneum, the size of the berry of it was near 3 -?4 folds, which was bigger than the Chinese cultivars (No.4 - No.6) of Rhus vernicifera et al. It had more than 5% ~ 10% of lacquer wax in pericard, and contained less than 6% - 8% of lacquer oil in seed. No.1 had lower acid value (A.V) and iodine value (I.V);the key factors for this were cultivar and its growing environment. The principal constituents of lacquer waxes of No.1?- No.6 were triglycerides of fatty acids with total saturated fatty acids (TSFA) of 75% - 82.7%, total unsaturated fatty acids (TUSFA) of 15.1% - 20%, and total dibasic acids (TDBA) of 5%. The CIEL a b system and Hunter whiteness formula were used to evaluate the bleaching effect on lacquer wax by physical adsorption and ultraviolet (UV) irradiation. The optimal conditions of physical decoloration were determined for activated carbon: kieselguhr = 3:2 (g/g) as adsorbent, a ratio of 1:20 (g/mL) for lacquer wax to petroleum ether, bleaching 30 min at 80?C. UV light achieved a good bleaching effect irradiated at 60?C for 60 hrs. UV irradiation definitely changed relative contents of fatty acids, TUSFA and TDBA decreased from 19.617% to 11.022% and 4.379% to 2.017% respectively, while TSFA could be raised from 76.462% to 86.077%, however, the mechanism of UV irradiation was still unclear and should be investigated in the future.

Investigation and development on processing of Vietnamese lacquer

Vietnamese sap and lacquerware have a splendid history. In order to promote a sustainable Vietnamese lacquer value chain, this review was carried out for us to investigate at site Vietnamese lacquer cultivation and processing of lacquer sap, then introduce the chemical components, HPLC-MS characteristic, properity and polymerization mechanism, as well as processing techniques of Vietnamese lacquer sap. Combined with the experience of lacquer cultivation and processing of Chinese lacquer, key problems to restrict the development of lacquer value chain were analyzed in Vietnam, and some suggestions would also be proposed in this investigation.

A Preliminary Study of Three Finishing Materials for Traditional Chinese Furniture

The traditional Chinese furniture evolved as an important part of the Chinese culture and civilization. Alongside design, structure, ornaments, the original finishes applied define the particularities and value of traditional Chinese furniture. This is because wood finishing not only enhances wood natural beauty by colour, gloss and highlighting of wooden texture, but also can be a means of exquisite decoration (e.g. engraved, gilded or painted lacquer works). Chinese lacquer, Tung oil and Chinese wax represent some of the most important finishing materials employed and were, therefore, selected for this study. The paper presents a brief macroscopic, microscopic and FTIR characterization of these materials. These results will be used as starting data in a further study on the ageing properties of these traditional finishing materials, useful for scientific conservation purposes.

Degradation of Japanese Lacquer under Wavelength Sensitivity of Light Radiation

Degradation of Japanese lacquer caused by light irradiation was examined at various wavelengths. By exposing lacquer specimens to a narrow monochromatic light band isolated from dispersed polychromatic light emitted by a Xe lamp source, the wavelength sensitivity characteristics of lacquer degradation could be determined on the basis of radiant energy. Tame-Urushi (brown) lacquer displayed peak degradation maxima at 220 and 315 nm. A broad shoulder peak was also observed in UVA. For Shu-Urushi (cinnabar) lacquer, in addition to peaks in the UVA–UVB range, a large degree of degradation was observed following exposure to light in the visible range. Ao-Urushi (green) lacquer showed similar characteristics, although it was less prone to degradation. Similarly, Shin-Urushi (black) lacquer showed little change in response to light, although UV light caused limited degradation. These results indicate that along with the damage caused by UVA and UVB, visible light in the range 510 - 650 nm may also have a significant degradation effect. Our results provide experimental evidence that Japanese lacquer responds differently to light of various wavelengths and that specific wavelengths, including visible light, can cause significant degradation.

VISCOSITY BEHAVIOR OF LACQUER POLYSACCHARIDE IN AQUEOUS SOLUTION

The dependence of measured viscosity on NaCl concentration (0.1 to 3.0M), pH (range of 2—13) and cadoxen composition w_(cad) (from 2% to 100%) for the lacquer polysaccharide in NaCl/cadoxen/H_2O mixture containing HCl or without were obtained. All the viscosity exponents γ in the Mark-Houwink equations under three different solvent condition arc close to 0.5. The w_(cad) dependence of reduced viscosity ηsp/c confirms the single strand chain of the polysaccharide. As the γ values close to 0.5 and values of unperturbed dimension <S^2>_θ/M and [η] much smaller than those for usual linear polymers, these facts suggest that the polysaccharide chains in the aqueous solutions should be dense random coil owing to the highly branched structure.

COMPACT COIL OF LACQUER POLYSACCARIDE:FURTHER EVIDENCE

The weight average molecular weights Mw,radii of gyration<s^2>^(1/2) second virial coefficients A_2,and intrinsic viscosities in 8 solvent [η]_θof five fractionated samples of the chinese lacquer polysaccharide were measured by light scattering and viscosimetry.It is further evidenced that the polysaccharide in aqueous solution exists as a compact coil resulted from highly branched structure.

LIGHT SCATTERING OF POLYSACCHARIDE FROM LACQUER IN AQUEOUS SOLUTION

The polysaccharide having weight-average molecular weight M_w=1. 09×10~5, isolated from the sap of lac trees (Vietnam), was separated into 12 fractions by aqueous-phase preparative gel permeation chromatography. The molecular weights and molecular weight distributions of the fractions were measured in aqueous 0.08M KCl/0.01 M NaAc and 0.4M KCl/0.05M NaAc at pH =7. 6 by light scattering, viscometry and gel permeation chromatography. The Mark-Houwink equation in aqueous 0.08M KCl/0.01M NaAc at 30℃ was found to be [η]= 2.28×10^(-2) M_w^(0.52) (cm^3/g), which indicated the polysaccharide chain in the aqueous solution to be a spherical random coil.

GEL PERMEATION CHROMATOGRAPHIC ANALYSIS OF LACQUER POLYSACCHARIDE

Ten fractionated samples of Chinese lacquer polysaccharide in aqueous 0.1M NaC1 solution were studied by aqueous-phase gel permeation chromatography （GPC）. The universal calibration, broad MWD calibration and corrected column dispersion were adopted to the analysis of GPC chromatograms of the polysaccharide. The molecular weights M;, M;and polydispersity index M;/M;obtained from GPC are in good agreement with the results of light scattering and membrane osmometry. It is verified that the universal calibration concept is applicable to the lacquer polysaccharide having a number of side chains.

INFLUENCES OF MOLECULAR WEIGHT AND BRANCHING PARAMETER OF LACQUER POLYSACCHARIDE ON THE GROWTH OF LEUCOCYTES

A method of determining branching parameter of lacquer polysaccharide wasestablished by acid-base back-titration of terminal uronic acid of branches. The branchingfactors obtained are in agreement with the values determined by colorimetric method withcarbazole and the results estimated by using Zimm-Stockmayer equation from viscositydata. Influences of molecular weights and branching factors of five fractions of lacquerpolysaccharide on the bioactivities were studied. The results show that the polysaccharideshave bioactivities in motivating the growth of leucocytes, and the effect increases with thedecrease of molecular weight and branching factor in the range studied (17×10~4 >M_w>4×10~4).

Exploration of Lacquer Heritage Across China in 2019

Exploration of Lacquer Heritage Across China by Experts in 2019 kicked off in Beijing.It was guided by the Department of Intangible Cultural Heritage, Ministry of Culture and Fourism, Hubei Provincial Department of Culture and Tourism and Jingzhou Municipal Bureau of Culture and Tourism and organized by Jingzhou Traditional Craft Workstation and Alliance for the Inheritance and Development of Lacquer Heritage (in preparation). The experts will visit the main lacquer production areas in China, breaking new ground lor the coordinated revitalization of the lacquer industry in China.

A Study on the Task Analysis and Performance Evaluation of Carved Lacquer Craft Inheritors in Novice Stage

The carved lacquer craft,a gem of traditional Chinese crafts,boasts a history of over 2,000 years and features craftsmanship of a superior order.This study attempts to investigate the typical tasks and learning result evaluation of carved lacquer apprentices at the novice stage by the method of qualitative research with 11 carved lacquer craft inheritors of a studio of a carved lacquer master.It is discovered that the design of carved lacquer draft sketches,the design of carved lacquer patterns,and the making and use of carved lacquer tools are typical tasks of novice apprentices,while the modeling and aesthetics of works,carving skills,and the level of interaction with the carved lacquer community are important criteria for evaluating the development of the skills of novice apprentices.

THE SYNTHESIS OF URUSHIOL TITANIUM CHELATE POLYMERS AND THEIR STRUCTURAL CHARACTERISTICS

The synthetic method and structural characteristics of urushiol-titanium chelates (UT) and urushiol-titanium chelate polymer for anticorrosive coatings have been studied.Two kinds of coating films made from UT polymer show excellent physico-mechanical properties and possess good chemical resistance to strong acids and alkalis, many kinds of salt solutions and organic solvents, stable at high temperature.

Study on Characteristics of Gold Powder with Round Shape for Maki-e

Maki-e is a traditional Japanese decorative technique that uses the natural lacquer Urushi and metal powders. Currently, there exist only two companies that manufacture metal powder for the purpose of Maki-e, and this research focuses on comparing the material characteristics of the gold powders with round shape manufactured by them. EDS (energy-dispersive X-ray spectroscopy) analysis, image analysis of particle shape before and after Maki-e processing, and color analysis of samples after Maki-e processing were carried out in this research. The study revealed that current gold powders with round shape had almost the same content ratio regardless of the manufacturing company and the powder diameter. In addition, spherical shape and irregular shape were observed in any gold powders, and the aggregates were observed in powder with increasing the powder diameter, while the shape of the aggregates differed with manufacturing companies. Therefore, it was indicated that the aggregates in the powder made by Asano Co., Ltd. had an influence on the particle diameter and its deviation after Maki-e processing. Moreover, the powder in Urushi resin has an influence on the Maki-e appearance because there is a color difference in polished powder, powder in Urushi resin, and Urushi resin.

Effect of Different Eggshell Powder on Appearance of Eggshell Maki-e

The Maki-e technique with eggshell powder is one of techniques of Japanese traditional Urushi (Japanese lacquer) crafts. However, this technique is relatively new in the history of Maki-e, and there are no prior researches in terms of materials, structure, and properties. In this research, therefore we have aimed to evaluate the relationship between the eggshell powder sizes, dispersion, and color shade in Maki-e with eggshell powder. The difference between hen’s and quail’s eggshell characteristics and the effect of their powder particle size on appearance of eggshell Maki-e were discussed on the basis of the results of the particle size, circularity, particle number, and RGB value. As a result, it was found that the occupancy of the eggshell powder on the surface depends on not particle number but the particle size, whereas the whiteness of both eggshell powders depends on the particle size.

Study on the Appearance and Peel Strength of Byakudan-Nuri Works

This paper focuses on Byakudan-nuri, one of the traditional decoration techniques of Japanese Urushi (Urushi natural lacquer) crafts. Works produced by Byakudan-nuri express a unique luster color owing to painting gold or silver leaves along with highly transparent Urushi. The specific problem of Byakudan-nuri is the exfoliation of Urushi off the metal leaf surface, to solve a lot of repair work which is done nowadays. For Byakudan-nuri, silver leaf is preferred to a gold leaf. This paper tries to clarify the influence of the different kinds of metal leaves on the appearance and peel strength of works of Byakudan-nuri and, moreover, to elucidate the reason why silver leaf has been used more frequently for Byakudan-nuri until now. It was found out that the reason for the more frequent use of silver leaf in Byakudan-nuri is that silver does not seem to affect the appearance and peel strength in works produced by this technique.

Study on Properties of Silver Powder for Maki-e

Maki-e is a traditional Japanese decorative technique that uses the natural lacquer Urushi and metal powders. In 2014, there exist only two companies that manufacture silver powder for the purpose of Maki-e, and this study focuses on comparing the powders manufactured by them. Gloss and color of each silver powder were measured after Maki-e decoration was finished, and EDS (energy-dispersive X-ray spectroscopy) was used to determine the differences in their chemical composition. In addition, to verify the effect of polishing, residual gloss after sulfuration and polishing was measured. The study revealed that the shapes of the silver powders (Maru-fun, No. 1) manufactured by the two companies are different and it affects the occupancy rate of Urushi and powder, which in turn affects their gloss and color. Wakou silver has a very strong resistance to sulfuration;however, owing to its Pd content, its chroma is much lower than that of other powders. It was shown that sulfuration on powder surface can be removed by polishing irrespective of the shape and chemical composition ratio of the particles.

Simple,Inexpensive and Ecologically Friendly Derivative Spectrophotometric Fluconazole Assay from Nail Lacquer Formulations

Nail lacquers represent new drug form specifically designed to treat infected nail plate. They are complex organic solutions with specific assaying problems due to the high content of the polymer and plasticizer. Furthermore, there is a lack of assaying methods of active substances from this type of formulations in scientific literature. We developed derivative UV-spectrophotometric method for determination of fluconazole content in antifungal nail lacquer formulations. The method was validated for specificity, linearity, precision (repeatability), intermediate precision and accuracy (recovery). The method is specific, linear in the range of 99.53 - 497.65 μg/ml, precise and showed good recovery (98.79% - 101.77% from all six developed formulations). Besides, it is inexpensive, simple and nontoxic, i.e. ecologically acceptable. This method can be used for assaying fluconazole from this type of formulations.

成都老官山汉墓经穴髹漆人像十二经脉循行考证

In 2012,a lacquer figure was unearthed from the Han dynasty tomb(188 BC-87 BC) at Chengdu Laoguanshan.The lines intaglioed on the Laoguan mountain lacquer figure were similar to the meridians.Objective:To investigate the relationship between the lines on this Laoguanshan lacquer figure and the regular meridians so as to explore the development of meridian system in ancient China.Methods:Based on collecting the photos of the Laoguan mountain lacquer figure and the representative acupuncture classics,the double evidence method(combining the unearthed relics/literature and extant literature) was performed to investigate the relationship between the lines on this Laoguanshan lacquer figure and the regular meridians.Furthermore,the development of regular meridians theory was analyzed from the number,distribution,direction and branches.Results:The routes of the 28 longitudinal white lines on the Laoguan mountain lacquer figure are similar to the regular meridians in the ancient literature including Huángdì Nèijīng 《黄帝内经》 Yellow Emperor’s Inner Classic).The number,distribution and branches of the meridians intaglioed on the Laoguanshan lacquer figure suggested the evolution of the regular-meridian system from the eleven-meridian system to the twelve-meridian system.Conclusions:The meridian system of Laoguanshan lacquer figure was a link connecting the preceding and the following.The Laoguanshan lacquer figure played an important role in the development of the early meridian theory.