Epoxy additives

Synthetic resins form the heart of the paint industry. The tw o main types of synthetic resins are condensation polymers and addition polymers. Condensation polymers, formed by condensation of like or unlike molecules into a new, more complex compound, include polyesters, phenolics.. iniino resins, polyurethane, and epoxies. Addition polymers include polyvinyl acetate, polyvinyl chloride, and the acrylates,... 

Epoxy, on the other hand, is inexpensive, and is most highly regarded for its ease of fabrication with very little shrinkage and the ability to use a diversity of additives to obtain the desired properties. The epoxy addition reaction forms a... 

TABLE A.4 Trade Names and Manufacturers of Epoxy Additives... 

Polyetheriflcation means formation of an ether bond or sequence of ether bonds by (poly)addition of epoxy groups which is released by proton donors (like the OH group formed in the amine-epoxy addition), ionic catalysts or other initiators... 

During the early stages of cure (177°C), the predominant reaction is amine-epoxy addition represented by a third-order rate expression. 

Results obtained by the GPC and DSC studies are in excellent agreement. Correlations between GPC and DSC data provide a better understanding of epoxy resin cure behavior and are useful In assessing the effects of stoichiometry and impurities. Simple amine-to-epoxy addition is the predominant reaction between TGMDA and DDS during the early stages of cure. This reaction is adeguately described by a third-order rate expression (Eg. 10). 

The utility of polyaniline in corrosion resistant coatings has been noted [McAndrew et al., 1996]. The addition of polyaniline to acid containing polymers e.g., polyamic acid precursor of poly-imides, styrene-acrylic acid copolymers) allowed for polymeric doping and intermediate corrosion protection of the blends compared to the constituents. Epoxy addition and diisocyante terminated... 

Scheme 5. Intramolecular secondary amine-epoxy addition.

Uses Inks paint and varnish driers catalyst anodizing mineral supplement in feed additives foam stabilizer in food-pkg. adhesives polymerization catalyst in mfg. of paper/paperboard in contact with aq./ fatty foods catalyst for curing urethanes, epoxies additive in fuels, lubricants crosslinking reflective and conductive coatings on glass or other substrates... 

Uses Catalyst for curing urethanes, epoxies additive in fuels, lubricants reflective and conductive coatings on glass or other substrates crosslinking Regulatory SARA 313 reportable... 

Epoxy-amine systems follow an addition step-growth polymerisation mechanism. The two principal reactions of primary and secondary amines with epoxy oligomers are shown in Reaction scheme 1 [30]. These reactions are catalysed by acids, phenols and alcohols (e.g. impurities in commercial epoxy resins). The presence of water causes a tremendous acceleration, but does not alter the network structure. The hydroxyl groups formed by the amine-epoxy addition steps are also active catalysts, so that the curing reaction usually shows an accelerating effect in its early stage (autocatalysis). 

It should be noted that in all these experiments,amine-epoxy in combination with secondary amine-epoxy addition reactions are predominant in the reaction mechanism [30,97-99],... 

Only for strengthening purposes Sikagard 720 EpoCem , a cement-based mortar with epoxy additives, was used as matrix for the fabric. The assembling of the reinforcement consists of a 4 mm thick ground layer, the hybrid multi-axial fibre grid and a final 4 mm cover layer. 

In many commercial systems, etherification accompanying the amine-epoxy addition is an important curing reaction. It is released (initiated) by the OH group formed in the primary addition step. 

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