Ecofriendly synthesis and characterization of carboxylated GAP copolymers

Hancheul Kim; Yoorim Jang; Sitae Noh; Jongoh Jeong; Donghyun Kim; Byeongkwan Kang; Taewun Kang; Hyungtaek Choi; Hakjune Rhee

doi:10.1039/c8ra03643h

Ecofriendly synthesis and characterization of carboxylated GAP copolymers

RSC Adv. 2018 May 31;8(36):20032-20038. doi: 10.1039/c8ra03643h. eCollection 2018 May 30.

Authors

Hancheul Kim¹, Yoorim Jang¹, Sitae Noh², Jongoh Jeong³, Donghyun Kim⁴, Byeongkwan Kang⁴, Taewun Kang⁵, Hyungtaek Choi⁶, Hakjune Rhee^{1

7}

Affiliations

¹ Department of Bionanotechnology, Hanyang University 55 Hanyangdaehak-ro Sangnok-gu, Ansan Gyeonggi-do 15588 South Korea hrhee@hanyang.ac.kr.
² Department of Chemical Engineering, College of Engineering Sciences, Hanyang University 55 Hanyangdaehak-ro Sangnok-gu, Ansan Gyeonggi-do 15588 South Korea.
³ NOROO Paint & Coatings Co., Ltd. 351, Bakdal-ro Manan-gu, Anyang-si Gyeonggi-do 13977 South Korea.
⁴ Human and Culture Convergence R&D Group, Korea Institute of Industrial Technology 143 Hanggaulro Sangnok-gu, Ansan-si Gyeonggi-do 15588 South Korea.
⁵ Energetic Materials & Pyrotechnics, Defense R&D Center, Hanwha Corporation 10, Yuseong-daero 1366beon-gil, Yuseong-gu Daejeon 34101 South Korea.
⁶ Missile System Integration, Propulsion Center, Hanwha Corporation 99, Oesam-Ro 8beon-Gil, Yuseong-gu Daejeon 34060 South Korea.
⁷ Department of Applied Chemistry, Hanyang University 55 Hanyangdaehak-ro Sangnok-gu, Ansan Gyeonggi-do 15588 South Korea.

Abstract

Carboxylated GAP copolymers (polyGA-carboxylate) compounds (1-7), were synthesized by the simultaneous substitution reaction with PECH, sodium azide, and sodium carboxylate in DMSO. The synthesized compounds (1-7) were characterized by various analysis tools, such as Fourier transform infrared (FT-IR), inverse gated decoupling ¹³C-nuclear magnetic resonance (¹³C NMR), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), calorimetry, and friction and impact sensitivity. These poly(GA-carboxylate) compounds (1-7) have better thermal properties owing to their lower glass transition temperatures, from -48 °C to -55 °C, compared to glycidyl azide polymer (GAP) (-49 °C) and similar first thermal decomposition temperatures (228-230 °C) in comparison to GAP (227 °C), regardless of the introduction of the carboxylate group in GAP. Moreover, poly(GA_0.8-butyrate_0.2) and poly(GA_0.8-decanoate_0.2) have higher heats of combustion (2331 and 2976 kJ mol^-1) and negative formation enthalpies (-0.75 and -2.02 kJ g^-1), while GAP has a lower heat of combustion (2029 kJ mol^-1) and positive formation enthalpy (1.33 kJ g^-1). Therefore, poly(GA-carboxylate) could be a good candidate for the polymeric binder in solid propellants.