A Study on Formation and Thermal Decomposition Kinetics of PU Elastomers by Dynamic DSC and TGA Analysis

Dynamic DSC 및 TGA 열분석을 이용한 PU Elastomer의 중합반응 및 열분해 반응 Kinetics에 관한 연구

  • Yoon, Soo-Koong (Department of Chemical Engineering, Keimyung University) ;
  • Ahn, Won-Sool (Department of Chemical Engineering, Keimyung University)
  • 윤수공 (계명대학교 공과대학 화학공학과) ;
  • 안원술 (계명대학교 공과대학 화학공학과)
  • Published : 2007.03.31

Abstract

Reaction kinetics of polyurethane elastomers (PU) were studied using dynamic DSC and TGA for three PU samples of general purpose (Sample A), high temperature cross-likable CASE purpose with MOCA (Sample B), and RT cross-likable CASE purpose grade (Sample C). From DSC results, sample with MOCA(Sample B) showed lower shift of peak temperature, while showing broader thermograms than those of general purpose grade (Sample A). On the other hand, RT cross-linkable PU grade (Sample C) showed an interesting double mode reaction patterns, i.e., a lower temperature reaction at about $70\;^{\circ}C$, and a higher temperature reaction in the range of $140{\sim}170\;^{\circ}C$, indicating that it requires 2-step reaction process in order to complete the reaction. Once the cross-linking reaction completed, however, TGA results showed that all the samples would be considered to have similar chemical structures, showing similar decomposition processes. Sample C, especially, had showed decomposition properties of both Sample A and Sample B. Formation activation energies calculated from Kissinger method showed 10.39, 65.85, 36.52(Low $T_p$) and 18.21(High $T_p$) kcal/mol, while decomposition activation energies were 31.94, 30.84, 24.16 kcal/mol, respectively.

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