Epoxides, oligomers

Polymers based on epoxide oligomers and polyheteroarylenes 90MI33. 

Free-Volume in Epoxide Oligomer Before Crosslinking. 174... 

Fig- 2. A conventional production process of bisphenol-A type epoxide oligomer... 

Epoxide oligomers before crosslinking are characterized by a number of properties, such as epoxy content, melt (or solution) viscosity, volatile content, melting (or softening) point, color, or density [1-3]. These characterizations are usually made for quality control or the specification of products. In addition, GPC and HPLC are frequently used for studying the molecular composition or purity... 

These viscoelastic properties above the glass transition can be correlated with each other as the transport phenomenon in the same oligomer. The relationships between two of the these three properties previously listed are also important for a basic understanding of the nature of the uncured epoxide oligomer. 

The melt viscosity of the DGEBA oligomer is measured in many cases by the cone-plate type viscometer [59-62]. Figure 4 shows viscosity-angular frequency curves [61] for Epikote 1002 (Mw=1891,Tg=39 °C) at 90 and 120°C. The epoxide oligomer exhibits Newtonian flow behavior up to a relatively high angular... 

Prediction of Tg of Curing System from Data on Epoxide Oligomers Before Crosslinking... 

In139) the researchers studied the nonisothermal kinetics of polyaddition reactions of oxiranes to aromatic amines up to high conversion levels, as well as the kinetic laws governing the curing of epoxide oligomers by diamines under the conditions of a propagating reaction front. 

A.A. Bejev, Epoxide Oligomers, Polymers and Composite Materials on their Basis with Improved Working Characteristics, Tashkent Technological Institute, 1991. [PhD Thesis]... 

During the thermal decomposition of viscous epoxide oligomers, phenols are mainly released. These processes proceed via homolytic and heterolj ic mechanisms followed by the splitting of the bisphenol link to form phenol and isopropylphenol. Thermal conversions leading to the cyclisation and formation of benzopyran structures are also possible, but of minor importance. 

Epoxide oligomers and gluing compositions. Edited by Grekov A. K. Naukova dumka, Moscow, 1990. 200 p. 

Metal-free reactions represent a direct way to study the confinement effects induced by the nanotube itself. Few such reactions have been carried out within CNTs, but notable examples include the formation of linear structures, such as fuUerene [151] and fullerene epoxide oligomers [174], formation of DWCNTs from endohedral fiiUerenes encapsulated in SWCNTs [71,155,156], or from encapsulated ferrocene [165], graphene nanoribbons (GNR) [186,187], the transformation of [Fe(C6oMc5)Cp] into encapsulated C70 [157], or the transformation of adamantane [188] and functionalized diamantine [189] in carbon chains. 

Shkadinskii, K.G., Rozenberg, B.A., and Yenikolopyan, N.S. (1978) The mechanism of epoxide oligomer hardening by diamines under advancing reaction front conditions. Polym. Sci. 

Relationship Between Melt Viscosity and Dielectric Relaxation Time for a Series of Epoxide Oligomers... 

The epoxide oligomer has difierent molecular weights according to the variation of the repeated number n in the structural formula. The epoxide oligomer at room temperature is a viscous liquid or amorphous solid according to the molecular weight. 

Flow properties of epoxide oligomers were reported by several workers. Aleman [2,3] discussed shear-rate effects on the shear viscosity measured by an Instron rheometer and found that each epoxide oligomer studied had Newtonian behavior up to the shear rate of 2000 sec Ghijsels et al. [4] reported that the temperature dependence of the zero-shear viscosity was... 

Sasabe and Saito [15] investigated the relationship between the dielectric relaxation time and the dc conductivity for several amorphous polymers, such as poly(vinyl chloride) (PVC) and poly(vinylidene chloride) (PVDC), and reported that the same relationships as in Eq. (1) were applicable to those polymers. In addition, the exponent m for the polymers was found to have a linear dependence on the 7 below 60°C. In order to obtain the relationship between two exponents, k and m, and Tg for the epoxide oligomer, the two exponents were plotted as a function of Tg in Fig. 7. Each exponent... 

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