Development of an eco-friendly hybrid lacquer based on kurome lacquer sap

An eco-friendly hybrid lacquer that dries quickly in a low relative humidity environment was synthesized using kurome lacquer (KL) and volatile organic compound-free hydrolyzed amine-functionalized silane (HAS). The HAS structure was characterized by nuclear magnetic resonance (NMR), and the results showed that the ethoxysilyl group in N-(2-aminoethyl)-3-aminopropyltriethoxysilane was completely hydrolyzed. After hybridization with the kurome lacquer, the properties of the hybrid lacquer were measured in detail including viscosity, molecular weight, drying behaviors, and film hardness. Viscosity measurements confirmed the mechanism of hydrolysis and the condensation reaction of silane.     

Effects of hybridization of lacquer sap with organic silane on drying properties

A hybrid lacquer that dries quickly in low relative humidity was synthesized from liquid kurome lacquer and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AATMS). Hybridization improved the film (mechanical strength and thermal stability) and drying properties of lacquer paints fairly well. The reaction mechanisms between lacquer sap and AATMS were evaluated by various techniques, including NMR spectroscopy, IR spectroscopy, and GPC analysis. The reaction mechanisms were confirmed by the shifts of aromatic proton/carbon signals and the appearance of a methanol peak at the cleavage of the methoxysilyl groups (Si–O–CH₃) and phenolic hydroxyl groups (Ph–OH) of urushiol that were demonstrated by various NMR spectra and IR spectra. Due to these reactions, high molecular weight contents were increased. We considered that the drying properties of the hybrid lacquer were improved by the combination of alcoholysis, the sol–gel reaction, and general curing reaction of lacquer sap.     

Urushi (oriental lacquer) — a natural aesthetic durable and future-promising coating

What is oriental lacquer? This article attempts an answer to this question from the viewpoint of materials chemistry and coatings technology of the lacquer in Japan and also describes a strategy for developing oriental lacquers in harmony with the natural environment.     

A facile and scalable coating technique of carbon fibers with carbon nanoparticles for surface adhesion enhancement of fibers and resin in 2D C/C composites

In order to improve mechanical properties of 2D carbon-carbon composite via increasing fiber/matrix interfacial adhesion, we have developed a simple, low cost and scalable method for carbon fibers (CFs) coating. This method is inspired to ink printing process in which pigments/dyes are transferred and set on the different surfaces via proper chemical bindings. For this purpose, we have used colloidal suspension of carbon nanoparticles in printing ink solution and coated the surfaces through dip-coating procedure. The results of SEM observations showed that colloidal suspension of nano-carbon particles in ink solution could be successfully used as a coating solution for preparing a uniform, well distributed and defect-free coating. Also water wettability measurement test has been conducted in order to evaluate the carbon coating on the surface chemistry of carbon nanofibers. The results revealed significant improvement on wettability of CFs after coating owing to abundant hydrophilic groups introduced from ink solution onto the surface of CFs (approved by FTIR spectroscopy). Finally, the mechanical properties of 2D C/C composites prepared by as-received and nano-coated CFs have been evaluated. The result of mechanical properties showed remarkable improvement in both flexural and shear strength of final composite by 15% and 18%, respectively.     

Development of a fast drying hybrid lacquer in a low‐relative‐humidity environment based on kurome lacquer sap

Hybrid lacquers that dry quickly in a low‐relative‐humidity environment were synthesized with the repeated kurome lacquer process and an organic silicone compound. An investigation by gel permeation chromatography showed that fractions with different molecular weights showed a lower monomer concentration than the pure kurome lacquer. Fourier transform infrared spectra of the hybrid lacquers revealed that absorption due to the ether of the quinone olefin and/or dibenzofuran appeared around 1470 and 1080 cm^?1 and increased with the number of drying days. The gel fractions in the lacquer films increased according to the number of drying days, and this showed that the hybrid lacquers had higher gel fractions than the pure kurome lacquer in the initial stage of dryness. In addition, the drying mechanism of the hybrid lacquers was analyzed with an automatic drying time recorder and rigid‐body pendulum physical property testing measurements. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1055–1061, 2005     

谈生漆几种特性的启示

本文从生漆工艺的角度谈谈对生漆几种特性的看法。     

塑料制品防火涂料的制备和应用

介绍了一种塑料制品防火涂料的制备和使用方法，并扼要地阐述了该产品的基本性能和防火机理。     

耐磨涂覆树脂2448K的开发与生产

通过对国内外具有代表性的两种涂覆级低密度聚乙烯(LDPE)产品进行物性分析,确定涂覆专用树脂的技术指标;通过分析大庆LDPE装置工艺技术特点,确定了2448K的生产操作条件,生产出耐磨涂覆树脂2448K产品,性能满足用户要求.     

磷酸盐基胶粘剂的研究与应用

介绍了磷酸盐基胶粘剂的组成,讨论了磷酸盐基胶粘剂的耐高温性、低污染性、轻质性、粘接无破坏性等特点,论述了目前常用磷酸盐基胶粘剂的制备方法以及在复合材料、陶瓷材料、涂料和耐火材料方面的应用,并指出了磷酸盐基胶粘剂的研究发展方向。     

Separation and purification of isobutanol from dilute aqueous solutions by a hybrid hydrophobic/hydrophilic pervaporation process

In this study, a hybrid hydrophobic/hydrophilic pervaporation process was employed to separate and purify isobutanol from its dilute aqueous solutions. For this purpose, composite polydimethylsiloxane membranes were initially used for the recovery of isobutanol by hydrophobic pervaporation. Then the hydrophilic pervaporation with a composite polyvinyl alcohol membrane was utilized to separate water from the organic phase of the permeate stream of the hydrophobic pervaporation. The effect of feed flow rate on the performance of pervaporation was investigated. The resistance in series model was also applied to calculate the transport resistances through the composite membranes. It was observed that an enhancement in the feed flow rate led to higher permeation flux and selectivity of the more permeable component, while the flux of the less permeable component was almost constant. Also, the ratio of liquid boundary layer resistance to membrane layer resistance decreased by an increase in the feed flow rate. The isobutanol with a purity of higher than 99 wt.% was produced by the hybrid hydrophobic/hydrophilic pervaporation technique from a 2 wt.% aqueous isobutanol solution.     

Concomitant cationic polymerization of a hybrid monomer and an epoxy resin

The concomitant cationic polymerization of an epoxy resin and a hybrid monomer is a new concept for toughening epoxy resins. Thermolatent super acids are superior initiators of twin monomer polymerization and copolymerization. Determination of gel yield and instrumental characterization of the formed complex polymer network indicate that copolymerization occurs, integrating the linear silicone and novolak formed during twin polymerization into the epoxy network.     

Preparation of mullite-TiB2-CNTs hybrid composite through spark plasma sintering

A near fully dense mullite-TiB₂-CNTs hybrid composite was prepared successfully trough spark plasma sintering. 1 wt%CNT and 10 wt%TiB₂ were mixed with nano-sized mullite powders using a high energy mixer mill. Spark plasma sintering was carried out at 1350 °C under the primary and final pressure of 10 MPa and 30 MPa, respectively. XRD results showed mullite and TiB₂ as dominant crystalline phases accompanied by tiny peaks of alumina. The microstructure of prepared composites demonstrated uniform distribution of TiB₂ reinforcements in mullite matrix without any pores and porosities as a result of near fully densified spark plasma sintered composite. The fracture surface of composite revealed a proper bonding of TiB₂ with mullite matrix and also areas with CNTs tunneling and superficies as a result of pulling-out phenomenon. The flexural strength of 531 ± 28 MPa, Vickers harness of 18.31 ± 0.3 GPa, and fracture toughness of 5.46 ± 0.12 MPa m^−1/2 were achieved for prepared composites as the measured mechanical properties.     

Thermal conductivity of natural rubber nanocomposites with hybrid fillers

Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H_2O_2) and distilled water(H_2O). The functional groups on the surface of CNTs, changes in nanotube structure and morphology were characterized by Fourier transform infrared spectroscopy(FT-IR), Raman Spectroscopy, and transmission electron microscopy(TEM). It shows that hydroxyl(OH·) is successfully introduced. The surface defects of modified CNTs were obviously higher than those of original CNTs, and the degree of agglomeration was greatly reduced. Thermal conductivity of the composites was tested by protection heat flow meter method. Compared with unmodified CNTs/CB filling system, the thermal conductivity of hybrid composites is improved by an average of 5.8% with 1.5 phr(phr is parts per hundred rubber) of hydroxyl CNTs and 40 phr of CB filled. A three-dimensional heat conduction network composed of hydroxyl CNTs and CB, as observed by TEM, contributes to the good properties. Thermal conductivity of the hybrid composites increases as temperature rises. The mechanical properties of hybrid composites are also good with hydroxyl CNTs filled nanocomposites; the tensile strength, 100% and 300% tensile stress are improved by 10.1%, 22.4% and 26.2% respectively.     

Development of a new procedure for lipid extraction from Hevea brasiliensis natural rubber

Non‐isoprene components and especially lipids have been reported to be involved in some key properties of natural rubber. Unfortunately, these results are hardly comparable due to different extraction methods. This work aimed to optimize lipid extraction from natural rubber either in the liquid state (latex) or in the dry state (unsmoked sheets). Extraction of unsmoked sheets from the RRIM 600 clone was carried out with different combinations of organic solvents (chloroform/methanol and hexane/isopropanol mixes). Chloroform/methanol (2 : 1 vol/vol) was found to be the most suitable for lipid extraction from unsmoked sheet rubber. The lipid extraction yield was improved by increasing the exchange surfaces by grinding rubber under liquid nitrogen and extracting the ground rubber for 6 h at room temperature, leading to 1.82% lipid extraction yield (versus dry rubber). Concerning latex extraction, the problem of lipid entrapment in the coagulum from immediate coagulation of latex in the solvent was solved by preliminary two times dilution of latex, giving a 3.24% extract (versus dry rubber) containing a minimum quantity of contaminating polyisoprene. Concerning the nature of lipids, dilution increased mainly neutral lipid extraction, which may suggest that neutral lipids were those entrapped by coagulation.     

Development of hybrid antifouling paints

The objectives of this study are to measure the efficiency of a hybrid system for antifouling paint and to observe the influence of the physico-chemical properties of the binder on the antifouling activity. Poly(ɛ-caprolactone) (PCL) and poly(dimethylsiloxane) (PDMS) homopolymers are already used as binder for different antifouling strategies. The use of the block copolymer should allow to mix the properties of erosion and hydrophobicity to obtain a more efficient paint with a reduced environmental impact.Paints containing triblock copolymer were immersed in seawater in Lorient harbour to evaluate their antifouling activities. The water absorption, the degradation and the surface properties of the copolymer were measured in distilled water to understand the influence of the binder characteristics in the resulting antifouling properties.The hybrid paints have shown efficiency close to a commercial paint during their immersion in situ in spite of inadequate static conditions of test.     

Purification and carbon-film-coating of natural graphite as anode materials for Li-ion batteries

A process of modification of natural graphite materials as anode for lithium ion batteries was attempted. The process started with the treatment of natural graphite with concentrated hydrochloric acid and concentrated sulfuric acid in a thermal autoclave, followed by the in situ polymerization of resorcinol-formaldehyde resin to coat the graphite, then heat-treatment. SEM, XRD, Raman and electrochemical charge-discharge analysis showed that the surface defects and impurities on natural graphite were eliminated by purification of the concentrated acids, and carbon-film encapsulation modified the surface structure of the graphite and reduced its BET surface area. The as-obtained natural graphite sample presented an initial charge-discharge coulombic efficiency of 88.4% and a reversible capacity of 355.8 mAh g⁻¹. The proposed process paves a way to prepare a promising anode material with excellent performance with low cost of natural graphite for rechargeable lithium ion batteries.     

天然鳞片石墨/环氧树脂复合材料的制备及导热性能研究

以天然鳞片石墨为导热填料,E44型环氧树脂为基体,采用超声分散法制备天然鳞片石墨/环氧树脂复合导热材料.系统考察了天然鳞片石墨用量、石墨粒度和炭黑添加量等因素对复合材料导热性能的影响.结果表明:随着天然鳞片石墨用量增加,复合材料的导热系数增大,抗压强度先增加后减小;复合材料的导热系数随天然石墨粒径的增大而增大,抗压强度先减小后增加;在石墨/环氧树脂复合导热材料中添加不同用量的炭黑时,随着炭黑添加量的增加,复合材料的抗压强度增大,导热系数先增大后减小.制备天然鳞片石墨/环氧树脂复合导热材料的最佳配方为天然鳞片石墨用量45％,粒径≤270 μm,炭黑用量2％.     

Use of silane coupling agents to enhance the performance of adhesively bonded alumina to resin hybrid composites

Silane coupling agents were employed to improve the adhesion of vinyl-ester to alumina (Al₂O₃). Shear test by compression loading (ASTM D905) was used to study dry and wet adhesion. Scanning electron microscopy (SEM) was used to study the uniformity of silane coatings and the fracture modes after shear testing. Results showed that the adhesion and durability of the sandwiched alumina/vinyl-ester systems were significantly improved by certain silane surface treatment for most of the systems.     

天然气水合物资源勘探开发技术研究进展

天然气水合物储量巨大,是人类理想的潜在的替代能源。对世界天然气水合物资源基本特征和分布情况进行了介绍,对国内外天然气水合物勘探开发技术以及环境效应进行了阐述。     

Development of an autoignition submodel for natural gas engines

This paper describes a new autoignition submodel for engine modeling codes. This submodel does not require extensive computational resources and is easily portable to various computational environments. It also considers variation of natural gas composition due to propane addition. Computation results show that the knock occurrence crank angle can be predicted within 2° CA when the model is coupled to a zero-dimensional engine model, which was also developed for the present work. The results with the model incorporated into a multi-dimensional model (KIVA) are also promising. KIVA was able to predict if the engine was going to knock or not and also gave correct trends in the knock intensity.