Minor components ofLesquerella fendleri seed oil

Routine analysis of fatty ester fractions ofLesquerella fendleri oil suggested the presence of epoxy compounds and other minor components. By a combination of open silica column and high performance liquid chromatography (HPLC) fractionations of the methyl esters prepared from the oil, these constitutents were isolated and then characterized by thin-layer chromatography-mass spectrometry (GC-MS—electron ionization, EI, and chemical ionization, CI) and nuclear magnetic resonance (NMR—¹H and¹³C). Three epoxy acids, 15,16-epoxy-9,12-octadecadienoic, 9,10-epoxy-12-octadecenoic and 9,10-epoxy-octadecanoic, were found. Hydroxy acids present included a C-22 homologue of lesquerolic acid (16-hydroxy-12-docosenoic acid) and 14,15-dihydroxy-tricosanoic acid. Other minor ocmponents included four sterols, brassicasterol, campesterol, β-sitosterol and stigmasterol, and a series of saturated and unsaturated fatty acids up to C30. Visiting postdoctoral scientist sponsored by the government of India.     

玻璃钢复合材料基体树脂的发展现状

本文主要介绍玻璃钢复合材料基体树脂近几年发展情况，介绍基体树脂改性和应用，主要包括：不饱和聚酯树脂、环氧树脂、乙烯基酯树脂、酚醛树脂，还简单介绍了热塑性基体树脂及应用。     

Radiochemical ageing of an amine cured epoxy network. Part I: change of physical properties

An aromatic rich, amine cured epoxy network (initial glass transition temperature 250 °C), was irradiated in air (pressure 0.22 MPa), at 30 and 120 °C, by gamma rays with two dose rates 2 and 20 kGy/h, for doses upto 70 MGy. The following characteristics were recorded, thickness of oxidised layer (TOL) from IR microspectrophotometry, flexural strength σ_R, toughness K_IC and glass transition temperature T_g. σ_R decreases from 120 MPa to about 40 MPa in the most degraded samples. This decrease is sharply linked to TOL showing the key role of the oxidised layer in crack initiation. K_IC decreases from 0.7 to 0.55 MPa m^1/2. Data are too much scattered to allow a kinetic study but it appears that, in the early period of exposure, K_IC decreases more rapidly at 120 °C than at 30 °C. T_g decreases from 250 to 140 °C in the most degraded samples, and the decrease is faster at 30 °C than at 120 °C. The decrease of T_g is attributed to a predominant chain scission process. The decrease of K_IC can be attributed to a combination of chain scission and physical ageing or chain scission and crosslinking. A relationship between T_g and the number of chain scissions, derived from the Di Marzio's theory, is proposed.     

端羟基聚醚改性环氧树脂研究

合成了不同分子量(450,1200,2000)的端羟基聚醚(mPEG)改性双酚A型环氧树脂,通过DSC、动态热机械分析(DMA)研究了mPEG/EP的固化反应活性及改性环氧树脂酸酐固化体系的热性能与冲击性能进行了研究,并用扫描电子显微镜(SEM)分析了冲击试样断面。结果表明,改性体系的固化反应活性略有降低;在mPEG含量为15%时固化体系的冲击韧性都达到最大值;改性环氧树脂固化体系的玻璃化转变温度(Tg)随mPEG的含量增大有所降低,且相同质量下mPEG分子量越小下降幅度越大。     

Anticorrosive properties of the epoxy–cardanol resin based paints

An epoxy–cardanol resin was developed using epichlorohydrin, bisphenol-A and cardanol. On evaluation it was found that epoxy–cardanol resin exhibits better properties as compared to epoxy resin in terms of increase in tensile strength, elongation, bond with steel and lowering of water vapour transmission of the film. The improvement in these properties indicated that the paints based on modified resin would be more durable than the epoxy based paints. Accordingly, paints were formulated using the developed resin and their performance were compared with their counterparts made with unmodified epoxy resin. Zinc powder, zinc phosphate, micaceous iron oxide and synthetic iron oxide were used as pigments along with fillers, additives and an aromatic polyamine adduct hardener. For both types of paints similar doses of pigments and additives were used. Physico-mechanical properties, chemical resistance and corrosion protection efficiency of the formulated paints were determined. It was found that the anticorrosive properties of epoxy–cardanol resin based paints are superior to that of the paints formulated with the unmodified epoxy resin. Micaceous iron oxide based paints in epoxy–cardanol resin showed the best performance followed by zinc phosphate based paints. It is concluded that the developed resin is a better binder media for the formulation of paints.     

锌粉含量对环氧富锌漆防锈性能的影响

研究了环氧富锌漆中锌粉含量对其漆膜防锈性能的影响。     

环氧树脂改性氰酸酯树脂的研究

研究了环氧树脂改性双酚 A型氰酸酯树脂体系的物理性能、粘度特性、反应性和贮存稳定性以及固化树脂的力学性能、耐热性、耐湿热性和介电性能     

The process modelling of epoxy dispensing for microchip encapsulation using fuzzy linear regression with fuzzy intervals

Epoxy dispensing is a popular way to perform microchip encapsulation for chip-on-board (COB) packages. However, the determination of the proper process parameters setting for a satisfactory encapsulation quality is difficult due to the complex behaviour of the encapsulant during the dispensing process and the inherent fuzziness of epoxy dispensing systems. Sometimes, the observed values from the process may be irregular. In conventional regression models, deviations between the observed values and the estimated values are supposed to have a probability distribution. However, when data is scattered, the obtained regression model has too wide of a possibility range. These deviations in processes such as epoxy dispensing can be regarded as system fuzziness that can be dealt with satisfactorily using a fuzzy regression method. In this paper, the fuzzy linear regression concept with fuzzy intervals and its application to the process modelling of epoxy dispensing for microchip encapsulation are described. Two fuzzy regression models, expressing the correlation between various process parameters and the two quality characteristics, respectively, were developed. Validation experiments were performed to demonstrate the effectiveness of the method for process modelling.     

环氧富锌聚苯胺杂化金属重防腐水性涂料的研制

通过溶液聚合方法,把不同的聚苯胺产品与环氧富锌杂化制成了金属重防腐使用的水性涂料.经过与国际著名的金属重防腐溶剂型油漆进行对比检测,这种水性重防腐涂料的优异防腐性能得到了印证.由于不使用有机溶剂,所以制成的金属重防腐水性涂料是VOC含量很低和对环境友好的金属重防腐工业涂料.     

聚氨酯改性环氧树脂光学结构胶的研制

采用自制的端异氰酸基聚醚型聚氨酯预聚体对环氧树脂进行改性,对其添加量对改性树脂的性能的影响进行了考察,并与A-12胶黏剂的性能做了综合对比。结果表明环氧树脂增韧改性后对多种材料都具有良好的粘接性能,其中冲击强度由未改性时的12．1kJ／m^2提高到24．4kJ／m^2,剥离强度由1．4kN／m提高到3．4kN／m,断裂伸长率由5．2％提高到14．8％;其耐高低温交变性能好,-60～100℃循环5次玻璃未炸裂,并具有优异的耐介质性能。