VAAR vinyl acetate alcohol resins

Man-made binders Bakelite resin, polyester resin, chlorinated rubber, polyvinyl chloride, Thiokol rubber, epoxy resin, Thiokol-epoxy blends, vinyl acetate alcohol resin (VAAR), Viton-A, Teflon and Kel-F800 etc. 

Vinyl Acetate Alcohol Resins These may be considered as a vinyl acetate/vinyl alcohol copolymers consisting of 82% vinyl acetate and 18% vinyl alcohol and is supplied as a solid dissolved in methyl alcohol (18%) and methyl acetate (82%) or technical grade methyl acetate. It is popularly known as VAAR. Military specification MIL-V-50433 (MU), July 1969 governs the quality of its solution for use in ammunition. 

Scheme 5.1 Synthesis of vinyl acetate alcohol resin (VAAR).

Vinyl Alcohol-Acetate Resin (VAAR). According to the US Military specification (Ref 6) the resin consists of a mixt of approx 28% solids and 72% solvent. The solids are approx 18% hydroxyl content by wt calcd as vinyl alcohol and 82% as vinyl acetate. The solvent is tech grade methyl acetate (82% pure). The spec requirements are Color - Equivalent to No 300 Pt Co std when a sample aliquot soln is compared visually using 100ml tail-form Nessler tubes against a white background... 

It should also be mentioned that stearic acid or graphite is some times added in small amounts as an additive to smoke compositions. These materials serve as a lubricant, which really helps reduce sensitivities (especially to friction and impact) of smoke mixes. As for pyrotechnic binders in smokes, vinyl alcohol acetate resin (VAAR) has been used in the past. The most commonly used binder system now in smokes is polyvinyl alcohol (PVA), and it is applied wet. 

The U.S. military has used a material called vinyl alcohol-acetate resin (VAAR) as one of its primary binders for pyrotechnic compositions. VAAR is able to produce a good binding effect at low percentage by weight in many compositions compared to many of the other common binders. It is soluble in a methyl alcohol-methyl acetate solvent blend, and displays excellent long-term stability with a variety of compositions. 

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