Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Abstract

AbstractToday's ammunition still consists of about 70 wt% structure‐providing materials such as metals providing no energetic contribution. Therefore, reactive structure materials (RSMs) offer tremendous room for improvement. While current research focuses on rather heavy, metal‐based materials (e. g., alloys, thermites), energetic polymers appear as an under‐recognized opportunity for very lightweight RSMs. Unfortunately, suitable polymers are unavailable as energetic polymer research has almost exclusively focused on elastic binders with the least possible glass transition temperature. An application as RSM, however, requires rigid polymers with a glass transition above operational temperatures. Accordingly, monomers with fundamentally different structures are required. The first step in this particular direction is 3‐(2,4,6‐trinitrophenoxy)oxetane (TNPO). Herein, we report the synthesis of its homopolymer and investigate its polymerization behavior by copolymerization with prior art energetic oxetanes. All polymers were intensively studied by vibrational and multinuclear (1H, 13C, 14N) NMR spectroscopy, elemental analysis, gel permeation chromatography, and differential scanning calorimetry (DSC). Hereby, DSC revealed the high effect of the TNPO repeating unit on the glass transition temperature. The performance of all polymers was calculated using the EXPLO5 code to evaluate the potential performance range of polymeric RSMs. Further, their shock and friction sensitivity was determined by BAM standard procedures.