Physical and mechanical characterization of near-zero shrinkage polybenzoxazines

Abstract

A new class of phenolic‐like thermosetting resins has been developed that is based on the ring‐opening polymerization of a benzoxazine precursor. These new materials were developed to combine the thermal properties and flame retardance of phenolics with the mechanical performance and molecular design flexibility of advanced epoxy systems. The polybenzoxazines overcome many of the traditional shortcomings of conventional novolak and resoletype phenolic resins, while retaining their benefits. The physical and mechanical properties of these new polybenzoxazines are investigated and are shown to compare very favorably with those of conventional phenolic and epoxy resins. The ring‐opening polymerization of these new materials occurs with either near‐zero shrinkage or even a slight expansion upon cure. Dynamic mechanical analysis reveals that these candidates for composite applications possess high moduli and glass transition temperatures, but low crosslink densities. Long‐term immersion studies indicate that these materials have a low rate of water absorption and low saturation content. Impact, tensile, and flexural properties are also studied. Results of the dielectric analysis on these polybenzoxazines demonstrate the suitability of these materials for electrical applications. © 1996 John Wiley & Sons, Inc.

Synthesis, Characterization and Thermally-Activated Curing of Azobenzene-Containing Benzoxazines

“…The chemical structure of benzene and butyl substituted compounds, namely 3-phenyl-6-(phenyldiazenyl)-3,4-dihydro-2H-benzo[e] [1,3]oxazine (AzoP-a) and 3-butyl-3,4-dihydro-2H-benzo[e] [1,3]oxazine (AzoP-b) was confirmed by both FT-IR and 1 H-NMR spectroscopy. The FT-IR spectrum presented in Fig.…”

“…These include nearly zero shrinkage upon curing [1], thermal stability [2,3] and chemical resistance [4]. Polybenzoxazines formed by thermally-activated ring-opening of the corresponding benzoxazines without any catalyst and without generating any by-products [4,5] (Scheme 1).…”

Effects of Polybenzoxazine on Shape Memory Properties of Polyurethanes with Amorphous and Crystalline Soft Segments

“…PB is a thermosetting resin with high T g , near-zero volume shrinkage upon curing, low water absorption, and high mechanical integrity [41][42][43][44]. The monomer of this resin, benzoxazine (BA-a), is synthesized by a solventless method from bisphenol-A, aniline, and paraformaldehyde.…”

Development and application of novel ring‐opening polymerizations to functional networked polymers

“…10 Because of these properties, 1,3-benzoxazine has attracted much attention in the material science as a hopeful candidate of next generation materials for the aerospace application. Another significant advantage of benzoxazine is its easy synthesis from the corresponding phenolic compound, amine, and formaldehyde.…”