Carboxy-terminated butadiene

Carboxy-Terminated Poly butadiene Propellant Formulation... 

Hydroxy-terminated polybutadiene (HTPB) is considered to be the best binder for obtaining high combustion performance, superior elongation properties at low temperatures, and superior mechanical strength properties at high temperatures. This combination of properties is difficult to achieve in double-base propellants. HTPB is characterized by terminal -OH groups on a butadiene polymer. The other type of butadiene polymer used is carboxy-terminated polybutadiene (CTPB), which is cured with an imine or an epoxy resin. It should be noted that CTPB is somewhat sensitive to humidity, which has an adverse effect on its ageing charac-... 

Poly butadienes. Hydroxyl-terminated polybutadienes are comparatively late comers and are still in the development stage. They combine the high specific impulse of the well-proved carboxy-terminated polybutadienes with the clean, stoichiometric urethane reaction yielding propellants with unsurpassed mechanical properties. 

The rockets with solid composite propellants consisting of ammonium perchlorate (oxidizer), pulverized aluminum powder, special additives and binder-cum-fuel such as poly(butadiene-acrylic acid-acrylonitrile (PBAN), carboxy-terminated... 

Inert binders Polybutadiene and cellulose derivatives are used as binders for LOVA formulations [24]. The commonly used polybutadiene-based binders are hydroxy-terminated polybutadiene (HTPB) and carboxy-terminated polybutadiene (CTPB)/poly(butadiene-acrylonitrile) (PBAN) while the most commonly used cellulose derivatives are ethyl cellulose (EC), cellulose acetate (CA), cellulose acetate butyrate (CAB) and cellulose... 

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.)... 

CTPH — Carboxy Terminated Poly butadiene Tree radical terminated polymers. 

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... 

Epoxy-Terminated Poly (butadiene-co-acrylonitrile) (ETBN). A mixture of 730 g of bisphenol A diglycidyl ether (5.4 mol epoxy/kg), 200 g of carboxy-terminated poly (butadiene-co-acrylontrile) (Hycar 1300 x 13 from BFGoodrich, 26 wt% acrylonitrile content, acid number of 32 mg KOH/g), 64 g of bisphenol A, and 5 g triphenylphosphin was heated at 130 °C for 3 h to yield ETBN with a viscosity of 130,000 mPa-s (40 °C) and 3.3 mol epoxy/kg. 

Using the same approach, ABA block copolymers (with TBA segments forming block A) were prepared using bifunctional telechelic amino- or carboxy-terminated polybutadiene or poly(butadiene-co-acrylonitrile). The latters are commercially... 

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... 

Thus, with two equations and two unknowns, a unique solution to X and Y can be calculated. Carboxy-terminated copolymers of butadiene and acrylonitrile (CTBN) can be incorporated into the epoxy resin through a simple esterification reaction. One equivalent of carboxylic acid is esterified by one equivalent of epoxide. This reaction is again catalyzed by triphenylphosphine. Since, for our reactions, the limiting reagent in the esterification is the CTBN elastomer, the product is an elastomer capped with an epoxy resin. The epoxy terminated rubber is then capable of reacting in the usual manner with curing agents or in the previously discussed advancement reaction (Reaction Scheme 2). 

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. 

CTBN carboxy-terminated butadiene nitrile rubbers... 

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