Remarkable improvement of thermal stability of main‐chain benzoxazine oligomer by incorporating o‐norbornene as terminal functionality |
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Authors: | Kan Zhang Jiaming Qiu Songjun Li Zhikun Shang Jinyun Wang |
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Affiliation: | School of Materials Science and Engineering, Jiangsu University, Zhenjiang, China |
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Abstract: | A new main‐chain benzoxazine oligomer with o‐norbornene functionality as end groups has been designed and synthesized. As compared to traditional main‐chain type benzoxazine polymers, this benzoxazine oligomer with o‐norbornene terminal functionality can undergo further crosslinking polymerization after general ring‐opening polymerization of oxazine rings. Another main‐chain benzoxazine oligomer has also been designed based on the reaction of bisphenol‐A, 4,4′‐diaminodiphenylmethane, paraformaldehyde, and phenol for comparison. The structure of the synthesized oligomers is confirmed by 1H nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy (FTIR). The molecular weight has been determined by using gel permeation chromatography (GPC). The benzoxazine oligomer containing o‐norbornene functionality can polymerize with multiple polymerization mechanisms rather than the single mechanism common to traditional 1,3‐benzoxazine resins. The polymerization mechanisms are monitored by in situ FTIR and differential scanning calorimetry (DSC). Moreover, the thermoset derived from the benzoxazine oligomer containing o‐norbornene functionality exhibits high thermal stability with the transition temperature of 360 °C and a high Td5 of 404 °C. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45408. |
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Keywords: | ring‐opening polymerization thermal properties thermosets |
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