Synthesis and Characterization of Aromatic Diamine-Based Benzoxazines and thermal properties of resulting thermosets

• Main Authors: Chao-Wei Hsieh, 謝昭偉
• Other Authors: 林慶炫
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/90020365745945664711

碩士 === 國立中興大學 === 化學工程學系所 === 95 === Abstract Four high-purity aromatic diamines-based benzoxazines, which could not easily be synthesized by traditional approaches, were successfully synthesized by a facile, widely useful three-step synthetic method using four typical aromatic diamines – DDM, DDS, BAPP, and BAB, respectively, as starting materials. The structures of the monomers were confirmed by 1H-NMR, 13C-NMR, 1H-1H 2D NMR and 1H-13C 2D NMR spectra. Their high performance thermosets, were obtained by thermal curing of benzoxazines, and their properties were studied and compared with polymer derived from F-a, a typical aromatic biphenol-based benzoxazine. The aromatic-diamines based polybenzoxazines exhibit higher glass transition temperature and thermal stability than most conventional aromatic biphenols-based polybenzoxazines. Among the benzoxazines, DDM-Bz and F-a are constitutional isomers, but the Tg value and 5% decomposition temperature of P(DDM-Bz) are 53 and 111 oC, respectively higher than those of P(F-a), demonstrating the power of the molecule-approach to enhance the thermal properties. Because of the large varieties of aromatic diamines, this approach can increase the molecule-design flexibility of benzoxazines. The second experiment is addition of DOPO on the imine linkage of DDM-HB、DDS-HB and BAPP-HB，result in intermediates with a secondary amine linkage. The last step is the ring closure condensation of P-DDM-HB、P-DDS-HB and P-BAPP-HB, leading to benzoxazine (P-DDM-Bz、P-DDS-Bz and P-BAPP-Bz).To promote thermal stability and Mechanical characterization of copolymers based on P-Bz and Functionized polymers( DDM-Bz、F-a and epoxy).