Synthesis and characterization of carboxylated PBAMO copolymers as promising prepolymers for energetic binders

Minkyung Lim; Meilan Bu; Yoorim Jang; Jongoh Jeong; Sitae Noh; Hakjune Rhee

doi:10.1039/c9ra09881j

Synthesis and characterization of carboxylated PBAMO copolymers as promising prepolymers for energetic binders

RSC Adv. 2020 Mar 2;10(15):8967-8972. doi: 10.1039/c9ra09881j. eCollection 2020 Feb 27.

Authors

Minkyung Lim¹, Meilan Bu¹, Yoorim Jang¹, Jongoh Jeong², Sitae Noh³, Hakjune Rhee^{1

4}

Affiliations

¹ Department of Bionanotechnology, Hanyang University 55 Hanyangdaehak-ro, Sangnok-gu Ansan Gyeonggi-do 15588 South Korea hrhee@hanyang.ac.kr.
² NOROO Paint & Coatings Co., Ltd. 351, Bakdal-ro, Manan-gu Anyang-si Gyeonggido 13977 South Korea.
³ Department of Materials Science and Chemical Engineering, Hanyang University 55 Hanyangdaehak-ro, Sangnok-gu Ansan Gyeonggi-do 15588 South Korea.
⁴ Department of Applied Chemistry, Hanyang University 55 Hanyangdaehak-ro, Sangnok-gu Ansan Gyeonggi-do 15588 South Korea.

Abstract

The carboxylated poly[3,3-bis(3-azidomethyl)oxetane] (PBAMO) copolymers (poly(BAMO-carboxylate)) were synthesized by substitution of poly[3,3-bis(3-chloromethyl)oxetane] (PBCMO) with potassium carboxylate and sodium azide in DMSO. The synthesized compounds were characterized using various analytical techniques, such as Fourier-transform infrared (FT-IR) spectroscopy, inverse-gated decoupling ¹³C-nuclear magnetic resonance (¹³C NMR) spectroscopy, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), calorimetry, friction, and impact sensitivity analysis. These poly(BAMO-carboxylate) compounds have better thermal properties, with lower glass transition temperatures (ranging from -43 °C to -51 °C) than PBAMO (-37 °C) and higher thermal decomposition temperatures (233-237 °C) than PBAMO (211 °C). Moreover, poly(BAMO_0.80-octanoate_0.20) and poly(BAMO_0.78-decanoate_0.22) have higher heats of combustion (5226 and 5665 kJ mol^-1, respectively) and negative formation enthalpies (-0.17 and -0.55 kJ g^-1, respectively), while PBAMO has lower heat of combustion (3125 kJ mol^-1) and positive formation enthalpy (0.06 kJ g^-1). The poly(BAMO-carboxylate) compounds have higher values (38-50 J) than that of PBAMO (14 J) in the impact sensitivities. This is a valuable study for improving the properties of PBAMO, which is a high energetic polymeric binder but difficult to handle because of its sensitivity. Therefore, poly(BAMO-carboxylate) could be a good candidate as a prepolymer for designing the energetic polymeric binder.