Hydroxy-terminated polybutadiene HTPB

The polymeric hydrocarbon also acts as a binder of the particles, holding them together so as to formulate a propellant grain. Ammonium perchlorate (AP) is a typical crystalline oxidizer and hydroxy-terminated polybutadiene (HTPB) is a typical polymeric fuel. When AP and HTPB are decomposed thermally on the propellant surface, oxidizer and fuel gases are produced, which diffuse into each other and react to produce high-temperature combustion gases. 

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-... 

Typical examples of HCP are hydroxy-terminated polybutadiene (HTPB), car-boxy-terminated polybutadiene (CTPB), hydroxy-terminated polyether (HTPE), hydroxy-terminated polyester (HTPS), and hydroxy-terminated polyacetylene (HTPA). The physicochemical properties of various types of HCP are described in Section 4.2.3. 

There are a number of inert binders such as polyester, epoxy, polysulfide, polyurethane which have been reported as binders for composite propellants and plastic bonded explosives (PBXs). At present, hydroxy-terminated polybutadiene (HTPB) is regarded as the state-of-the-art workhorse binder for such applications. However, the recent trend is to use energetic binders such as poly [3,3-bis(azidomethyl oxetane)] [poly(BAMO)], poly (3-azidomethyl-3-methyl oxetane) [poly(AMMO)], PNP, GAP diol and triol, nitrated HTPB(NHTPB), poly(NiMMO), poly(GlyN) and nitrated cyclodextrin polymers poly(CDN) for PBXs and composite propellants in order to get better performance. 

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... 

Hydroxy-terminated polybutadiene HTPB [Structure (4.4)] prepared by... 

A hydroxy-terminated polybutadiene (HTPB)Zisophorone diisocyanate (IPDI) elastomer is commonly used as propellant binder material. Solid-state NMR relaxation times have been used as a means to predict the mechanical properties of the binder as a function of ageing time. 

The Hydrostatic Pressure Effect. The particular hydroxy-terminated polybutadiene (HTPB) solid propellant employed here is a polybutadi-... 

Heat capacity Jg- K MDI/hydroxy terminated polybutadiene (HTPB)/ 4,4 methyleme bis(2-chloroaniline (MOCA) 0.4 (6)... 

The kinetics of simultaneous IPN formation was studied [172] for the system comprising PU prepared with hydroxy-terminated polybutadiene (HTPB), diisocyanate, and chain-extending agent and styrene-DVB or PMMA cross-linked with EGDMA. The authors obtained the curing curves for individual networks and IPNs, and established that the formation rate of the PU component was higher than that for the other two networks under the chosen conditions. The reaction orders for PU and IPN are close to 1, whereas for cross-linked copolymers it is about 0.5. They concluded that the formation of IPNs is dominant. 

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