Viscoelastic properties of hydroxyl-terminated poly(butadiene) based composite rocket propellants

Abstract

In the present study, the viscoelastic response of three composite solid propellants based on hydroxyl-terminated poly(butadiene), ammonium perchlorate and aluminum has been investigated. The investigation was surveyed by dynamic mechanical analysis over a wide range of temperatures and frequencies. The mechanical properties of these materials are related to the macromolecular structure of the binder as well as to the content and nature of solid fillers. The storage modulus, loss modulus, loss factor and glass transition temperature for each propellant sample have been evaluated. The master curves of storage (log G' vs log ?) and loss modulus (log G'' vs log ?) were generated for each propellant. A comparison of logaT vs temperature curves for all propellants indicate conformance to Williams-Landel-Ferry equation. Choosing the glass transition as the reference temperature, WLF equation constants are determined. Fractional free volume at the glass transition temperature and thermal coefficient of free volume expansion values are in accordance with the consideration that Al is reinforcing filler.

Effect of tris (2,3-epoxypropyl) isocyanurate on dynamic modulus of CTBN-based composite rocket propellant

“…Nevertheless, the evidence of the thermorheological complex behaviour was observed as indicated by slightly different shift factors for G' and G''. This difference is more pronounced comparing to the tested HTPB-based composite propellants reported in our previous paper [21].…”

Thermobaric Effects of Cast Composite Explosives of Different Charge Masses and Dimensions

“…All of them were loaded with the chosen explosive composition, TBE-3 (HMX/AP/Al/Mg/HTPB = 45/10/21/9/15) [22,23], prepared using the following raw materials: -octogen (DINO − Norway), according to MIL-H-45444, -aluminium, according to MIL-STD-129, -magnesium (ECKA GRANULES − Austria), according to MIL-DTL-382D, -ammonium perchlorate, 7-10 μm, obtained by grinding 200 µm-АР on a vertical hammer mill ACM-10, -polymeric binder, based on hydroxyterminated polybutadiene (Tanyun, China) cured by isophorone-diisocyanate, including additives (plasticizer, antioxidant, and bonding agent). The stochiometric ratio of the curator to binder (NCO/OH ratio) was 0.975 for this formulation [23][24][25]. The experimental explosive composition was prepared in a vertical planetary kneading machine IKA HKV-5, under vacuum, at 50 °C.…”

Dynamic Mechanical Characterization of Composite Solid Propellant for Propellant Grain Structural Integrity Assessment

“…The most frequently used oxidizing agent and polymeric matrix are ammonium perchlorate (AP) and hydroxyl terminated polybutadiene (HTPB), respectively. Usually, aluminum (Al) in the form of particles is also a main constituent of the composition.…”