Accelerating effects of N‐aryl‐N′,N′‐dialkyl ureas on epoxy‐dicyandiamide curing system |
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| Authors: | Xiang Dong Liu Mika Kimura Atsushi Sudo Takeshi Endo |
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| Affiliation: | 1. Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, College of Materials and Textile, Zhejiang Sci‐Tech University, Xiasha Higher Education Zone, Hangzhou 310018, People's Republic of China;2. Molecular Engineering Institute, Kinki University, Kayanomori, Iizuka 820‐8555, Japan |
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| Abstract: | This report focuses on epoxy‐dicyandiamide (DICY) curing system accelerated by N‐aryl‐N′,N′‐dialkyl urea, aiming at clarifying the accelerating mechanism and the relationship between accelerating effect and molecular structure of the accelerators. Nine N‐aryl‐N′,N′‐dialkyl ureas were synthesized and investigated with measurements of differential scanning calorimetry, thermo gravimetric/differential thermal analysis and NMR spectroscopy. The results revealed that the ureas released the corresponding secondary amines by the thermal dissociation in the presence of epoxide, which led to the formation of tertiary amines that catalyze the addition reaction of DICY to epoxide. Moreover, a tendency that the ureas able to release more compact amines exhibited higher acceleration effects was discovered. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 |
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| Keywords: | accelerator cure dicyandiamide epoxy resin N‐aryl‐N′ ,N′ ‐disubstituted urea urea derivatives |
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