CTBN, epoxy toughness Structure

However, newer adhesives systems having moderate temperature resistance have been developed with improved toughness but without sacrificing other properties. When cured, these structural adhesives have discrete elastomeric particles embedded in the matrix. The most common toughened hybrids using this concept are acrylic and epoxy systems. The elastomer is generally a amine- or carboxyl-terminated acrylonitrile butadiene copolymer (ATBN and CTBN). 

Amine-cured epoxy resins are extensively used as structural matrices in composite manufacture and as such the improvement of their mechanical properties is very desirable. As in the case of polystyrene the addition of a rubber phase provides an energy dissipation mechanism below and this increases the toughness of the overall material. Carboxy-terminated butadiene acrylonitrile (CTBN) is initially soluble in the reaction mixture of digylcidyl ether of bisphenol A (DGEBA) and the low-temperature cure system triethylenetetra-amine (TFTA) ... 

Vinyl esters (also referred to as epoxy acrylates) are prepared from the epoxies (such as the Bisphenol A or novolac based epoxies) reacted with methacryhc acid leaving pendant vinyl groups capable of crosshnking as noted below. Styrene is typicaUy added in commercial apphcations to yield lower viscosity and lower cost [920]. Carboxy terminated butadiene-acylonitrile ohogmers (CTBN) can be added to improve toughness. The structure of a Bisphenol A based vinyl ester is ... 

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