N，N，N’，N’-四炔丙基-4，4＇-二氨基-二苯甲烷与4，4＇-联苯二苄叠氮固化动力学研究

分别利用FtIR和DSC技术对由N，N，N＇，N＇-四炔丙基4,4’-二氨基-二苯甲烷（TPDDM）与4，4’-联苯二苄叠氮（BAMBP）形成的一种新型三唑树脂的固化反应及其动力学进行了研究．TPDDM与BAMBP通过1，3-偶极环加成反应形成三唑五元环结构的聚合物，固化起始温度约为70℃，体系在较低温度下即可固化．反应体系的固化反应是一级反应，采用DSC法与FFIR法分别获得了表观聚合反应动力学参数，其结果具有一定的可比性．     

Phosphorus based epoxy terminated structural adhesive 2. Curing, adhesive strength and thermal stability

The curing behavior of phosphorus based epoxy terminated polymers was studied using diaminodiphenyl ether, diaminodiphenyl sulfone, benzophenone tetracarboxylic dianhydride and the commercial hardener of Ciba-Geigy's two-pack araldite, as curing agent. The adhesive strength of these adhesives was measured by various ASTM methods like lap-shear, peel, and cohesive tests on metal-metal, wood-wood and wood-metal interfaces. All these results were compared with the synthesized epoxy resins prepared from bisphenol-A and epichlorohydrin having the epoxy equivalent value of 0.519. The thermal stability of both the virgin resin and its cured form was also studied by thermogravimetric analysis.     

苯基二氨三嗪-甲醛树脂高温固化过程的红外光谱研究

本文通过不同平均加成度的A阶苯基二是三嗉甲醛树脂的红外光谱分析,对其红外吸收峰的归属进行了讨论。应用高温红外光谱和差谱技术对两种树脂样品的交联行为进行跟踪观察,由的红外吸收变化和反应体系中甲醛的检测推论了树脂的热固化反应。     

Novolac/乙烯-醋酸乙烯酯共聚物共混体系中的反应诱导Spinodal相分离

Ｎｏｖｏｌａｃ／乙烯 醋酸乙烯酯共聚物共混体系中的反应诱导Ｓｐｉｎｏｄａｌ相分离陈文杰吴坚江明（复旦大学高分子科学系和国家教委聚合物分子工程实验室上海２００４３３）关键词Ｓｐｉｎｏｄａｌ相分离，共混物，光散射，酚醛树脂，固化反应在高分子多相体系中，...     

Guide for Authors

The effects of epoxidized natural rubber (ENR) on the curing behaviors and adhesive strengths of an epoxy (diglycidyl ether of bisphenol-A) and dicyandiamide/2-methyl imidazole system are studied with differential thermal calorimetry (DSC), scanning electron microscopy (SEM), and Instron tensile testing instrument. From DSC analyses of specimens prepared with unsealed aluminum pans, it is obtained that the reaction exotherm, the time to maximal curing rate, the glass transition temperature, the rate constant, and the reaction order of the epoxy system change with respect to the content of ENR added because of the reaction of ENR with the epoxy system. The results obtained from SEM micrographs indicate that the particle size of the rubber phase increases with increasing the curing temperature and the ENR content. The volume fraction of the separated rubber phase also follows the similar trend except at the high curing temperature which implying that the dissolution of epoxy resin in the ENR phase also depends on the curing temperature and the amount of ENR present. The lap shear strengths of specimens prepared with etched aluminum substrates increase with increasing the curing temperature because of a better cure at a higher temperature, but decrease with increasing the ENR content resulting from an adverse effect of ENR on the mechanical properties of the cured resins.     

The Curing Process and Elastic Modulus of HTPB-Containing Polyurethanes

By means of the functionality distribution deduced and weight averaged functionality a and molecular size vb2, the sol-gel distribution equations of HTPB(Hydroxyl terminated polybutadiene) + TDI (Toluene-2, 4-diisocyanate) expressed by the model of Aai-B2 type polycondensation were solved and the elastic modulus were calculated. The experimental results of HTPB+TDI curing process indicate that a, vb2 and functionality distribution function are available basically.     

Kinetics and mechanism of the epoxide-amine polyaddition

The mechanism and kinetics of the epoxide-amine polyaddition reaction have been studied by isothermal and scanning DSC measurements. The initial concentrations of the reactants (epoxides: bisphenol-A-diglycidyl ether (DGEBA) and phenyl glycidyl ether (PGE), amines: N,N′-dibenzylethylenediamine (DBED) and aniline) in our model systems have been strongly varied. The suggested kinetic model describes the reaction behavior of mixtures with any initial epoxide/amine ratios over the whole range of cure by a single parameter set. To find the optimum kinetic parameters, we have solved the set of differential equations numerically by the technique of multivariate non-linear regression (Mult-NLR). Excellent agreement was obtained between calculated and experimental curves.     

Thermo-mechanical characterisation of in-plane properties for CSM E-glass epoxy polymer composite materials – Part 2: Young's modulus

The in-plane Young's modulus of a CSM E-glass/epoxy material is characterised through the use of dynamic mechanical analysis (DMA). The measured data is used to generate material models which describe the property behaviour as a function of conversion and temperature. Gelation of the epoxy resin plays a major role in the modulus development and is measured directly on the glass/epoxy material. The Young's modulus is described through a bi-functional model including the liquid/solid transition of the material. The evolution of Young's modulus is modelled by decoupling modulus increments caused by time and temperature, and is graphically illustrated through a Modulus-Temperature-Transformation (MTT) diagram. Based on the established material models presented in this paper and models in Part-1, it is feasible to assess residual stresses and shape distortions of composite parts made from this glass/epoxy material.     

Initial Steps in Thermal Degradation of Fractions of PVC with Different Tacticities

PVC samples were prepared in bulk by using AIBN and UV radiation as the initiator system. The polymerization temperatures were 40, 0, -25, and -50oC. The samples were fractionated by means of successive extractions with dioxane, tetrahydro-furan, and cyclohexanone, and two fractions of each sample were characterized in order to study their thermal degradation. This was carried out by conductivity measurements with the use of a differential conductimetry cell for degradations up to 0.1% and a single cell for degradations up to 0.4%. From the UV-visible spectra of equally degraded samples it is concluded that the higher the tacticity of PVC, the higher the proportion of long polyene sequences is; this behavior is independent of the conversion. The degraded samples were ozonized in order to measure the number of scissions per chain. This number was found to be low for syndiotactic samples and high for atactic samples, which is accounted for by the increased clustering of double bonds to form long polyene sequences in the more syndiotactic polymers. Previous results suggesting increased ease of propagation along syndiotactic sequences are therefore confirmed more quantitatively.     

Chemorheological study of the curing kinetics of a phenolic resol resin gelled

The changes in the resin viscosity, conductivity, mass, and enthalpy during curing reactions have been studied to obtain kinetic parameters that allow modeling of the resin behavior throughout its industrial application. In this work, isothermal rheological tests of a phenolic resol resin were performed in order to study its complex viscosity during crosslinking reactions. Samples were prepared by a precuring treatment in a heated plate press to reach gel point of the resin. Rheological analyses of resol resin curing were carried out at five different temperatures (80-100 °C), and the kinetic models of Arrhenius and Kiuna were applied. The resol resin curing presented an activation energy of 72.1 kJ/mol according to the Arrhenius model. The Kiuna model was proposed to fit the non-linear evolution of the resin’s complex viscosity at the highest temperatures. This kinetic model was suitable for predicting the changes in the complex viscosity of the resol resin after its gelation, and the process activation energy obtained for the second order polynomial applied in this model was 88.1 kJ/mol. In addition, the profile for the degree of curing of resol resin was determined from measurements of the material’s elastic modulus.