Synthesis and Characterization of Thermally Curable Benzoxazine‐Functionalized Polystyrene Macromonomers

Abstract

Summary: Thermally curable benzoxazine ring‐containing polystyrene macromonomers were synthesized and characterized. 1,4‐Dibromo‐2,5‐bis(bromomethyl)benzene and 1,4‐dibromo‐2‐(bromomethyl)benzene were used as initiators in the atom transfer radical polymerization of styrene. The resulting polymers were used in combination with 3‐aminophenylboronic acid hemisulfate, for a Suzuki coupling. The obtained polymers, with amino groups in the middle or end of the chains, were reacted with formaldehyde and phenol to yield benzoxazine ring‐containing macromonomers. In addition to the glass transition temperature of the polystyrene segment observed at ca. 105 °C, differential scanning calorimetry thermograms exhibit an exotherm at ca. 276 °C corresponding to the oxazine thermal polymerization. Both macromonomers undergo thermal curing with the formation of thermosets having polystyrene segments.Structure of the benzoxazine‐functionalized polystyrene.magnified imageStructure of the benzoxazine‐functionalized polystyrene.

Photoinitiated Free Radical Polymerization Using Benzoxazines as Hydrogen Donors

“…[18] We have recently reported several routes to incorporate these interesting P-a structures into polymer chains. [19][20][21] As part of our continuing interest in alternative photoinitiating systems, we now report the use of P-a as a hydrogen donor in conjunction with aromatic carbonyl photosensitizers in a photoinitiated free radical polymerization.…”

Facile approach to functionalizing polymers with specific chemical groups by an ozone treatment: Preparation of crosslinkable poly(vinylidene fluoride) possessing benzoxazine pendent groups

“…28 The benzoxazine reaction was traced with DSC measurements, and the thermograms are shown in Figure 3. PVDF-Bz exhibited an exothermic peak that arose from the ring-opening reaction of benzoxazine rings; it had its onset at 220 8C and was centered at 240 8C.…”

Synthesis, curing behavior, and thermal properties of fluorene-based benzoxazine-endcapped copoly(ether ketone ketone)s

“…Moreover, main-chain type poly(benzoxazine-co-urethane)s [30] and poly(benzoxazine-co-sulfones)s [31] have been successfully synthesized to modify the brittleness of polybenzoxazines. The telechelic polybenzoxazines with thermoplastic oligomers as a backbone were also found to be more efficient in improving the toughness of this kind of thermoset [32][33][34][35].…”