Epoxide equivalent weights

Deflection temperature obtained with resin having an epoxide equivalent weight (EEW) of 190. 

Epoxidation catalysts, organic titanium compounds as, 25 135 Epoxide determinations, 10 385 Epoxide equivalent mass (EEM), 10 355 Epoxide equivalent weight (EEW), 10 355, 361-363, 385... 

An homologous series of epoxy resins with constant epoxide equivalent weight and increasing branch concentration displayed increased melt viscosity and weight average molecular weight. 

If the resin chains are assumed to be linear with no side branching, and it is further assumed that an epoxy group terminates each end of the molecule, then the epoxide equivalent weight is one-half the average molecular weight of the epoxy resin. 

Epoxide equivalent weight Viscosity (mPas at 25°C) Density (gm/ml/at 20°C) > Colour number (Gardener) Bisphenol type... 

If a quantity per granune mole of epoxy resin is quoted the pbw of amine per 100 pbw resin is the quantity per gramme mole multiplied by 100 and divided by the epoxide equivalent weight of the resin. 

The amount of curative used with an adduct system is calculated from the epoxide equivalent weight of the adduct and the hydrogen equivalent weight of the curative. 

Figure B.l Conversion monograph to find the quantity of hardener to be used with 100 parts of resin. Example illustrated for resin DER 671, the epoxide equivalent weight (EEW) is approximately equal to 500 the amine hydrogen equivalent weight (AHEW) of the hardener (polyamide) is approximately 350 therefore, the suggested amount of curing agent to be used is 70 parts per 100 parts epoxy resin (phr). Reproduced with permission from Dow Chemical Co., Midland, MI, USA...

Epoxide Equivalent Weight Determination by Carbon-13 Nuclear Magnetic Resonance... 

In this paper we discuss the use of carbon-13 nmr to measure epoxide equivalent weights of epoxy resins based on the diglycidyl ether of bisphenol A (DGEBA). The results obtained to date indicate that the carbon-13 technique could be an attractive alternative to current methods. 

MONIZ AND poRANSKi Epoxide Equivalent Weight Determination 85... 

MONIZ AND PORANSKI Epoxide Equivalent Weight Determination 87... 

Materials used were the standard commercially available grades. "CARDOLITE" Brand NC-513 is 3M s monofunctional epoxy reactive diluent CR-100, 3M s flow control agent DC-200, Dow-Corning antifoam Cab-O-Sil, Cabot fumed silica Epon 1001-X-75, Shell solid epoxy resin as 75% solution in xylene Tint-Ayd( ) EP-30-01, Daniels predispersed titanium dioxide liquid epoxy resin, standard bis-phenol-A diglycidyl ether of epoxide equivalent weight 190 grams/equivalent. 

X3 respectively were used to formulate HC-M0, HC-M HC-M2, and HC-M3. The bromine content of resins and molding compounds were respectively 7.0- and 1.3 percent by weight. Epoxide equivalent weight of the resins was approximately 210. 

Compatibilizer NPES-909, bisphenol A type solid epoxy resin, epoxide equivalent weight (EEW) = 2026 g/eq (Nan Ya Plastics Corp., Taiwan). 

WPE = weight per epoxide, i.e., grams of resins needed to provide 1 molar equivalent of epoxide. Also referred to as EEW (epoxide equivalent weight) and EMM (epoxy molar mass). All three items are interchangeable. 

Another chosen example stems from the perceived benefits of combining solid and liquid carboxylic nitrile elastomers in the same modification scheme. This is particularly useful when a degree of tack is required in the system. Table VIII exhibits one approach for preparing such an elastomer-modified solid DGEBA resin. In this instance a resin (epoxide equivalent weight of 650) was prepared by advancing two available liquid epoxy resin adducts — one utilizing a liquid nitrile, the other a solid nitrile elastomer. 

The objective of this section is to characterize the thermal stability of uncured solid rubber-modified epoxy resins. The effects of extended thermal history on melt viscosity and epoxide equivalent weight are discussed. The influence of the type and concentration of CTBN elastomer in the solid rubber-modified epoxy resin on melt viscosity and EEW is also discussed. Mechanistic considerations are proposed to explain the side reactions which influence the thermal stability of solid rubber-modified epoxy resins. 

EPOXIDE EQUIVALENT WEIGHT SPECIFIC GRAVITY, 25°C VISCOSITY (CENTISTOKES)... 

For the system investigated here, the epoxide equivalent weight (FEW) was determined to be about 400 g equivalents, the average functionality was two. DICY has three amine and one imine proton. Assuming equal reactivity and stoichiometric reaction, optimum properties were expected for a 4 1 mix. As observed earlier, the ratio could be increased without affecting resin performance adversely. Therefore, a calorimetric study for optimizing the formulation and its cure was of interest. 

Pure DGEBA is a crystalline solid (mp 43°C) with an epoxide equivalent weight (EEW) of 170. The typical commercial unmodified liquid resins are viscous liquids with viscosities of 11,000-16,000 MPa s (= cP) at 25°C, and an epoxide equivalent weight of ca 188. 

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