Epoxy resin preparation

Gel-permeation chromatography studies of epoxy resins prepared by the taffy process shown n values = 0, 1, 2, 3, etc, whereas only even-numbered repeat units are observed for resins prepared by the advancement process. This is a consequence of adding a difunctional phenol to a diglycidyl ether derivative of a difunctional phenol in the polymer-forming step. 

Epoxy Adducts. The epoxy resin itself may be reacted with di- or polyfunctional reactants containing more than one epoxy group. The number of potential epoxy adducts is very large. Typical are phosphorous-containing epoxy resins prepared by reaction of diepoxies with acid dichlorides of phosphoric acids. This is accomplished at an acid diepoxy ratio of 1 2 in the presence of FeCl3 catalyst. Adducts may also be prepared by the reaction of chain hydroxyls. 

How are vegetable oil-based diglycidyl ether type epoxy resins prepared ... 

Hergenrother et al. have calculated the flaming combustion efficiency of epoxy resins prepared from various epo>y- or amine-functional organo-phosphorus compounds by dividing the EHC measured in fire calorimetiy tests (Ohio State University apparatus and cone) by the effective heat of complete combustion measured in a PCFC. The combustion efficiency ranged roughly from 0.6 to 0.8 versus 0.7 for the phosphorus-free epo)y resin) whatever the oxidation state of phosphorus and other parameters. The authors concluded that there is no discernible effect [...] on the combustion efficiency in the flame . 

Polythiols as crosslinking agents for epoxy resins prepared from the reaction of l,5-dimercapto-3-oxapentane and pentaerythritol triallyl ether [163]. 

Epoxy resins prepared from the reaction between bisphenol A (BPA) and epichlorohydrin are commercially the most important ones, covering around 80 to 85 % of the volume of epoxy resins used in the industry. Various BPA epoxy resins available on the market primarily differ in their MW, and can be categorized as ... 

On the contrary, certain formulations including polyfunctional resins tend to increase the viscosity of the prepolymeric mixture. This is true for epoxy resins prepared from prepolymeric novolac formo-phenolic resins (oligomerized in acidic medium) (see Section 16.3). These novolac resins are polyphenols that can react with epichlorhydrin to give polyepoxides. Their structure can be schematized by... 

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