Investigation of processing, thermal, and mechanical properties of a new composite matrix‐benzoxazine containing aldehyde group

Abstract

A new benzoxazine aldehyde group containing monomer 3-phenyl-6-formyl-3, 4-dihydro-2H-1, 3-benzoxazine (Ald-B) was synthesized via the Mannich reaction of formaldehyde, p-hydroxybenzaldehyde, and aniline. The viscosities and curing behavior of the resins were studied. The results indicated that Ald-B has an initial viscosity lower than 0.110 Pa s at 90-C and the maximum temperature of the exotherm was at 196-C. Dynamic mechanical analysis (DMA) of the copolymer of Ald-B and methylenedianiline-type bis-benzoxazine (B-BOZ) showed only one T g of 251-C and high crosslink density in the matrix. The thermal stability of the copolymer was improved noticeably and the char yield at 800-C is 68.4%. The tensile strength and flexural strength of this resin cast are 72 and 137 MPa, respectively.

An investigation on the effect of phenylboronic acid on the processibilities and thermal properties of bis-benzoxazine resins

“…Generally with excellent performance, the materials have the processing difficulty. Although BZs possess many advantages over other state-of-the-art thermosetting resins, their relatively high curing temperature as well as low char yield, inherent to the most thermosets, point to the need of modification to meet the requirements of high-performance ablative materials [3][4][5]. Accordingly, recent research has focused on how to improve the processibilities and thermal resistance of BZs for various applications.…”

“…It is expected that combining BZ with PBA will generate the new material having the best attributes of them. A bis-benzoxazine named as 3-phenyl-6-[(3-phenyl(2H,4H-benzo [3,4-e]1,3-oxazin-6-yl))methyl]-2H,4H-benzo[e]1,3-oxazaperhydroine (Scheme S1) which exhibits good mechanical properties, low water sorption, dimensional stability, and flame resistance [24,25], is chosen to study the effect of PBA on the processibilities and thermal properties of BZ. We hope that this study will inspire others to continue the work on boronic acids and their application in thermosetting resin systems.…”

High performance graphene oxide‐modified polybenzoxazine resin

“…In this work, the excellent properties of PRGO are further used to improve both the thermal stability and toughness of bis‐benzoxazine (B‐BOZ) resin (Scheme ) which possesses low viscosity, high thermal resistance, and excellent mechanical properties . As a novel thermosetting resin, PRGO modified B‐BOZ resin has good toughness, great thermal, and mechanical properties.…”

Modification of phenolic resin composites by hyperbranched polyborate and polybenzoxazine

“…While, BOZ is a good choice for effectively modifying the fluidity of PR or PR‐HBPB blends. First, since BOZ resin has the lowest viscosity at 90–120°C and does not cure at this temperature [32–34], good fluidity of BOZ is beneficial for the expelling of generated volatile from matrix during the molding process. Second, because BOZ is a ring‐opening cured thermoset resin with no by‐product release upon curing process, the volatile produced in PR‐HBPB blend and defects formed in its composite can be decreased with the introduced BOZ resin.…”