BACKGROUND Current pressurised metered dose asthma inhaler (pMDI) propellants are not inert pharmacologically as were previous chlorofluorocarbons, have smooth muscle relaxant' partial pressure effects in the lungs and inhaled hydrofluoroalkane 134a (norflurane) has anaesthetic effects. Volumes of propellant gas per actuation have never been measured. METHODS In-vitro studies measured gas vol...

Nitrocellulose is the main component in many types of ammunition, propellants and explosives. The principles of production for nitrocellulose have not changed much since the 19 th century when it started being industrially produced for this purpose. The character of the nitrocellulose has a large effect on the end products abilities. The aim of this study was to develop a method that would be a...

Chlorofluorocarbons (CFCs) damage stratospheric ozone permitting enhanced levels of ultraviolet B radiation to reach the Earth's surface. As a result, production of CFCs is now banned under the Montreal Protocol with the exception of their temporary continued use in pressurized metered dose inhalers used to treat those with airway disorders. Replacement propellants have now been identified and ...

The terms of the Montreal Protocol have eliminated chlorofluorocarbons (CFCs) and other ozone-depleting agents from commercial use, with the exemption of their use as propellants in metered-dose inhalers. Two new propellants have been approved for CFC substitutes: hydrofluoroalkane (HFA)-134a and HFA-227. An extensive safety program was conducted by the International Pharmaceutical Aerosol Cons...

Abstract The interfacial interaction between the main oxidant filler ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) matrix in AP/HTPB propellants were studied via an all-atom molecular dynamics simulation. results of simulation showed effects microscopic cross-linked structure matrix, stretching rate during uniaxial stretching, contact area on mechanical properties, such...

Composite solid propellants were prepared with and without nano-alloys (Ti-Co, Ti-Ni, Ti-Zn), where nano-alloys used as catalyst. These nano-alloys are prepared by hydrazine reduction method. Catalytic properties of these nanomaterials were measured on Ammonium perchorate/hydroxyterminatedpolybutadiene propellant by thermogravimetery analysis and differential thermal analysis. Both experimental...

The established state-of-the-art for composite solid propellant grain manufacture consists in mix-cast-cure process using hazardous chemicals and specific molds forming. In most of the cases, polyaddition oligomers involves isocyanate functional groups. Construction constraints limit feasibility geometries, confining pressure-time history rocket motors to some configurations. Composition pot-li...