ABSTRACT Polyvinyl nitrate (PVN) is a nitrate‐ester energetic binder that can be produced directly from polyvinyl alcohol—a cheap commodity feedstock—thereby offering potential cost and supply‐chain advantages over binders based on nitrocellulose and other specialty polymers. The previously reported instability of PVN has been attributed to residual nitrating species and other adventitious impurities. In this study we show that spray drying an acetone solution of PVN provides an effective purification route that preserves polymer‐chain integrity and extent of nitration. Elemental analysis indicates a high degree of nitration (DoN) (close to the theoretical maximum), while GPC shows no cleavage of the polymer backbone. Compared to conventionally washed PVN, the spray‐dried material (SD‐PVN) exhibits elevated thermal stability with DSC onset and peak decomposition temperatures of 187°C and 195°C, respectively, and a decomposition enthalpy of ∼2.5 kJ g −1 that is comparable to nitrocellulose. SD‐PVN shows a glass transition temperature ( T g ) of 37°C–52°C and a lower storage modulus than cross‐linked HTPB, indicating that cross‐linking or plasticisation would be required to tailor mechanical performance. Small‐scale hazard testing indicates that SD‐PVN is relatively insensitive to impact, friction and electrostatic discharge (ESD). Compatibility screening using DSC/TGA suggests that SD‐PVN is compatible with ammonium perchlorate (AP), less compatible with ammonium nitrate (AN) and incompatible with ammonium dinitramide (ADN). Collectively, these results demonstrate that the long‐standing stability limitations of PVN can be mitigated by spray drying, supporting further development of PVN as a practical, energetic binder.
Spice et al. (Tue,) studied this question.