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Synthesis and properties of main‐chain polybenzoxazines based on bisphenol‐S
Author(s) -
Parveen Shakila,
Kim Haekyoung
Publication year - 2018
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.24777
Subject(s) - materials science , bisphenol , thermal stability , thermosetting polymer , curing (chemistry) , monomer , polymer chemistry , bisphenol a , thermal decomposition , diamine , polymerization , polymer , chemical engineering , composite material , organic chemistry , epoxy , chemistry , engineering
Polybenzoxazines (PBzs) are novel thermosetting resins, having many prominent advantages, including high mechanical strength, innate flame retardancy, excellent dimensional stability, low water retention, beneficial dielectric, and relatively high char yields. In recent years, more attention has been paid to the synthesis of main‐chain PBz (MCPBz) precursors using difunctional amines and phenol. In this study, to enhance the rigidity and to improve the crosslink density of PBzs, novel high‐molecular‐weight PBz precursors were synthesized using bisphenol‐S, a diphenolic compound, and three different diamines (namely ethylene diamine, 1,4‐diaminobutane, and tetraethylenepentamine) through a Mannich‐type reaction. The onset of curing temperature for the three PBz precursors was much lower, in the range of 199–215°C, in comparison with bisphenol‐A and aniline‐based benzoxazine monomer [ T onset of BA‐a: 220°C]. The curing of PBz precursors proceeds via ring‐opening polymerization as monitored by FTIR analysis. Additionally, the polymer—PBz‐tepa possesses excellent thermal stability, showing 10% decomposition at 330°C with a char yield of 42.0%. Thus, the properties of PBz are greatly improved by preparing MCPBz and by incorporating sulfonyl group. POLYM. ENG. SCI., 58:1766–1773, 2018. © 2017 Society of Plastics Engineers