Carboxy-terminated butadiene acrylonitrile

Figure 13.7 Variation of yield stress (

Figure 13.8 Fracture energy of epoxy networks cured with DDS (diamino dipheny sulfone) versus the initial DGEBA (diglycidyl ether of bisphenol A) ( ) neat systems ( ) with 10% CTBN (27% AN). Rubber = CTBN carboxy-terminated butadiene acrylonitrile random copolymer. (Pearson and Yee, 1989 with kind permission from Kluwer Academic Publisher.)... 

The separate phases will be rich in one component but may have the other present as a minor component. In order to control compatibility the elastomer may have reactive end groups to enhance interfacial adhesion. A common example in epoxy-resin technology is the carboxy-terminated butadiene-acrylonitrile copolymer (CTBN). The structure is shown in Scheme 1.47. In this resin the solubility in the epoxy resin is conferred by the acrylonitrile group, and an increase in the fraction present decreases the upper critical solution temperature, with 26% acrylonitrile conferring total miscibility of CTBN with a DGEBA-based epoxy resin (Pascault et al, 2002). 

CTBN carboxy-terminated butadiene-acrylonitrile copolymer... 

The incorporation of elastomers into epoxy resins has been an active area of research over the past decade (1-11). The primary reason for this interest has been the improved toughness of the modified materials. We have limited our work to the carboxy-terminated butadiene-acrylonitrile copolymers (CTBN) produced by... 

The B. F. Goodrich Chemical Company produces monopolymers and copolymers with acrylonitrile. These are known as the Hylar series. Acrylonitrile increases the viscosity and imparts oil resistance, adhesion, and compatibility with epoxy resins. Carboxy-terminated butadiene-acrylonitrile copol)uner (CTBN) improves impact strength, low-temperature shear strength, and crack resistance in epoxy formulations. 

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) ... 

Carboxy-terminated butadiene acrylonitrile random copolymer (CTBN)... 

Thermoset epoxy resins were toughened by small elastomeric inclusions of a carboxy terminated butadiene-acrylonitrile (CTBN) random copolymer by Visconti and Marchessault [198], who showed the variation in size as a function of CTBN content by TEM and light scattering. A major study of rubber modified epoxy resins has been reported by Manzione et al. [202,203], who showed a range of morphologies which result in a range of mechanical properties, even for a single polymer. An amine cured rubber modified epoxy... 

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