中温固化环氧树脂复合材料基体的研究

本文介绍一种环氧／硼胺树脂体系（EM体系），该体系在120～150℃固化，固化物具有较高的综合性能，而且工艺性良好，具有较长的室温储存期，可作为碳纤维复合材料的基体，对体系进行了DSC分析，给出了固化工艺。     

中温固化环氧对脂复合材料基体的研究

本文介绍一种环氧／硼胺树脂体系，该体系在１２０－１５０℃固化，固化物具有较高的综合性能，而且工艺性良好，具有较长的室温储存期，可作为碳纤维复合材料的基体，对体系进行了ＤＳＣ分析，给出了固化工艺。     

潜伏性环氧树脂 体系固化反应动力学参数特征的研究

本文对二种潜伏性环氧树脂体系的固化反应动力学参数进行了讨论。结果认为，理想的潜伏性环氧树脂体系应具有较高的固化反应活化能（Ｅａ）和频率熵因子（Ａ）或者是具有可变化活化能－－即在室温下具有较高的固化反应活化能，而在高温下具有较低的固化反应活化能。理论分析与实验结果相吻合。     

辐射固化体系

光固化是一种快速发展的“绿色”新技术，从上世纪70年代至今，辐射固化技术在发达国家的应用越来越普及。和传统涂料固化技术相比，辐射固化具有节能无污染、高效、适用于热敏基材、性能优异、采用设备小等优点。本作郭西锋先生详细阐述了辐射固化机理，UV固化体系的重要组成部分，目前国内UV体系现状，并对UV体系的发展趋势作出预测。     

环氧封端聚苯醚/环氧树脂共混体系的固化动力学研究

以羟基封端低分子量聚苯醚、环氧氯丙烷为原料，制备出环氧封端的改性聚苯醚（PPOE）。采用示差扫描量热法（DSC）研究了PPOE与双酚A酚醛型环氧树脂（BNE-200）复合体系的固化动力学，计算了共混物固化反应的表观活化能和反应级数。结果表明：各样品在不同升温速率下均只有一个固化峰，固化体系接近于1级固化反应，说明PPOE与BNE-200具有比较好的相容性。随着PPOE用量的增加，固化特征温度呈降低趋势，固化的表观活化能降低。当PPOE用量为80%时，复合体系表观活化能为63.25 kJ/mol，比BNE-200的93.62 kJ/mol降低了32.4%，说明PPOE比BEN-200具有更高的反应活性。     

浇铸型不饱和聚酯树脂的研究

本文合成了具有良好性能的浇铸型不饱和聚酯树脂，对其性能作了进一步研究，结果表明在树脂分子结构一定的条件下，树脂的固化收缩率受单体使用量及填料使用量的影响较大，而固化速度及固化放热主要受固化体系的控制。     

潜伏性环氧树脂固化促进剂M-Cd的合成及其应用

采用间苯二胺和溴化镉合成了一种具有潜伏性的环氧树脂固化促进剂M－Cd它是一种络合物，将它应用于二氰二胺／环氧树脂脂固化体系的高温结构粘剂中，能够显著地降低粘剂的固化温度，缩短固化时间，本文还讨论了合成该促进剂主要成分的投料比，应用于二氰二胺／环氧树脂固化体系的高温结构胶粘剂中该促进剂的使用量以及固化条件对粘剂力学性能的影响，同时还考核了应用该促进剂M的高温结构胶粘剂的综合性能。     

改性低毒脲醛树脂的固化研究

研究了非等温过程中改性低毒脲醛树脂固化体系和未改性脲醛树脂固化体系的固化行为，并研究了不同固化剂施用量对改性树脂固化的影响，对不同树脂体系固化后的结构进行了表征。结果表明，改性的UF树脂固化后的交联度大于未改性树脂固化后的交联度。     

紫外光固化聚氨酯乳液的合成与性能研究

光固化具有下列优点：不用溶剂或只用少量溶剂，减小了对环境的污染；耗能少，可低温固化；固化设备占地面积少，适用于自动化生产等。光固化也有缺点，只能用于较薄的涂层；固化体系中的颜料或其他添加剂会严重影响固化效果；背光部位不能固化，对固化对象形状要求较严格。     

湿法缠绕用次中温固化的环氧树脂配方

采用自制改性液态芳香胺制得一种低粘度次中温固化环氧树脂体系，通过不同升温速率下的固化过程DSC扫描，研究了该体系的固化反应动力学，并据其优化了体系的固化制度。结果表明，该体系的表观固化反应活化能为38．54kJ／mol，反应级数为0．84。固化度和FT—IR测试表明，体系可在90℃次中温环境中达到固化完全。体系综合性能优良，可满足复合材料湿法缠绕成型对高性能树脂基体的要求。     

中温固化碳纤维／环氧复合材料研究

介绍中温固化的EM环氧树脂及其复合材料的性能,以及固化工艺和应用情况;对EM环氧树脂体系在湿法预浸料制造过程中的“白化”现象进行了分析探讨,解决了湿法预浸料制作中594固化剂在丙酮中的溶解发白现象。     

EM菌液在活性污泥系统中的实验研究

有效微生物应用于活性污泥系统中,分别进行了EM复壮、EM投加及EM絮凝性能的研究。研究表明：用糖蜜、蜂蜜及高浓度污水均能有效的复壮EM;在活性污泥系统中投EM液,可以提高系统的处理效率;EM复活液具有一定的生物絮凝性能。     

Effect of processing parameters on the vulcanisation of natural rubber using glutaraldehyde

The process ability of vulcanising natural rubber using glutaraldehyde at low temperature has been studied. The main objective of this work is to improve the properties and stability of natural rubber (NR) using glutaraldehyde as a curing agent. In this study, the vulcanised samples were prepared systematically and compared with sulphur cured natural rubber vulcanisates. The influence of mole ratio of ammonia and glutaraldehyde, and the processing parameters (i.e. curing time and temperature) was investigated. The cured NR based on glutaraldehyde exhibited better hardness and thermal properties than that of the NR cured from conventional sulphur system. The experimental results reveal that the properties of glutaraldehyde cured NR can be developed with the proper additives combination and conditions adopted in the preparation. This cured system is very interesting due to it can be used for high temperature industrial applications. Moreover, it eases of processing at low temperature and cost.     

紫外光快速定位法在超细粉体分散性研究中的应用

用金相显微镜法观察纳/微米级颗粒在分散体系中的分散性时，由于颗粒处于不断的游动状态，很难确定颗粒在分散体系中分散的真实效果。本提供一种新的方法，通过紫外光辐射含有纳/微米颗粒的分散体系，使其在较短的时问内固化，达到快速定位体系中粒子的作用，从而较真实的反映粉体的原始分散状态。     

Robust identification of piecewise/switching autoregressive exogenous process

A robust identification approach for a class of switching processes named PWARX (piecewise autoregressive exogenous) processes is developed in this article. It is proposed that the identification problem can be formulated and solved within the EM (expectation‐maximization) algorithm framework. However, unlike the regular EM algorithm in which the objective function of the maximization step is built upon the assumption that the noise comes from a single distribution, contaminated Gaussian distribution is utilized in the process of constructing the objective function, which effectively makes the revised EM algorithm robust to the latent outliers. Issues associated with the EM algorithm in the PWARX system identification such as sensitivity to its starting point as well as inability to accurately classify “un‐decidable” data points are examined and a solution strategy is proposed. Data sets with/without outliers are both considered and the performance is compared between the robust EM algorithm and regular EM algorithm in terms of their parameter estimation performance. Finally, a modified version of MRLP (multi‐category robust linear programming) region partition method is proposed by assigning different weights to different data points. In this way, negative influence caused by outliers could be minimized in region partitioning of PWARX systems. Simulation as well as application on a pilot‐scale switched process control system are used to verify the efficiency of the proposed identification algorithm. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Effect of thermal degradation on the mechanical properties of a diglycidyl ether of bisphenol A/1,3-bisaminomethylcyclohexane (DGEBA/1,3-BAC) epoxy resin system

The effect of thermal degradation on the mechanical properties of a diglycidyl ether of bisphenol A (DGEBA)/1,3-bisaminomethylcyclohexane (1,3-BAC) epoxy system, cured with two different curing cycles—a short cycle and a long cycle—were studied using tensile and Izod impact experiments and scanning electronic microscopy, SEM, observations. From these experiments it can be noted a loss of mechanical properties of the material cured with both cycles with aging time, although the material cured with the long cycle presents better properties at any aging time. This better behavior can be explained from the time temperature transformation, TTT, diagram of this system. A good correlation was observed between the decrease in the intensity of the peak of β transition in tan δ curve obtained by dynamic mechanical analysis, DMA, and the decrease of the Izod impact strength when thermal aging is increasing. Also, a good correlation can be found between the increase in the fragility of the material with aging time and the morphology of fractured surfaces observed by SEM. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1841–1849, 1997     

Comparison of ML–EM algorithm and ART for reconstruction of gas hold-up profile in a bubble column

Algebraic reconstruction technique (ART) and maximum likelihood–expectation maximization (ML–EM) algorithm have been applied for image reconstruction using gamma-ray tomography. This methodology can be of immense help in establishing the hydrodynamics of several multiphase systems such as two-phase and three-phase bubble column reactors. The effect of various image processing parameters such as initial guess, grid size, stopping criteria and gamma-ray measurement parameters like beam configuration, number of projection, number of views on the quality of reconstructed image has been studied in present work. It has been observed that ML–EM algorithm shows more precise and faster results as compared to ART and it serve as a preferential tool in image reconstruction. These techniques were then used in the estimation of gas hold-up profile in a two-phase aqueous system. Average gas hold-up values in bubble column based on reconstructed local hold-up values based on the above two techniques were found to be in good agreement with the experimental data within ±10% accuracy, however, ML–EM algorithm may be preferred due to better capability of incorporating the modalities of data collection.     

The application of ultra-violet microscopy to thermosetting polymers

Optical microscopy with ultra-violet illumination has been used to monitor the curing reactions and final structure of an amine-cured epoxy resin system. When low concentrations of u.v. absorbing additive are added to the resin before curing, the additive is usually completely uniformly distributed in the cured product. No density variations on a scale resolvable in optical microscopy are visible. Similarly when a u.v. absorbing eragent is allowed to diffuse into the cured resin its diffusion profile is normal and shows no detectable density fluctuations in the resin. Reaction of cured resins with a reagent which couples with amino groups to give u.v. absorbing adducts shows that conventional hand mixing techniques do not produce complete mixing of the resin components and spatially non-uniform concentrations of unreacted amines are found. This effect can only be removed by unusually thorough mixing techniques. Use of a water soluble u.v. absorber allows penetration of the epoxy by water to be followed. In particular, the penetration of fibre-matrix interfaces by water can be visualised.     

Rutile TiO2 nanorod with anomalous resonance for charge storage and frequency selective absorption

TiO₂ is not among the traditional electromagnetic (EM) absorbing material candidates owing to its poor response in the EM wave region. Although the EM wave absorption performance can be improved by hybrid and/or hydrogenated TiO₂, the difficulty and risk of the experimental process are increased. Herein, rutile TiO₂ nanorod was successfully prepared by two-step method. The analysis of dielectric properties exhibits that rutile TiO₂ nanorod has excellent charge storage capacity. The results of EM wave absorbing performance show that impedance matching caused by anomalous resonance leads to frequency selective absorption. Such anomalous resonance is due to the resonant polarization of ionic clusters formed by oxygen ions and titanium ions. Moreover, metastructure design shows that the EM absorption frequency and the EM wave absorption bandwidth can be tuned through the design of metamaterial. Our founding will broaden the field of vision for the design of EM wave absorbing materials in the future.