Combining polybenzoxazines and polybutadienes via simultaneous inverse and direct vulcanization for flexible and recyclable thermosets by polysulfide dynamic bonding

Abstract

Simultaneous inverse and direct vulcanization of a benzoxazine and a polybutadiene gave recyclable films through dynamic S–S bonding.

Corrosion Resistance of Mild Steel Coated with Phthalimide-Functionalized Polybenzoxazines

“…The signal of the methyl group appeared at 2.01 ppm. Figures 3b and 4b present the 13 Furthermore, the structures of pPP-BZ and oPP-BZ monomers were confirmed using FTIR spectroscopy (Figures 5 and 6). The signals at 1778 and 1717 cm −1 for pPP-BZ and at 1772 and 1720 cm −1 for oPP-BZ represent asymmetric and symmetric stretching, respectively, of the C-C(=O)-C units of their imide groups [37].…”

“…1 H NMR (CDCl 3 , δ, ppm): 4.5 (s, ArCH 2 N), 5.2 (s, OCH 2 N), 6.75-7.9 (ArH, 14H). 13 A solution of p-toluidine (1.0 g, 0.0093 mol) and paraformaldehyde (0.80 g, 0.030 mol) in 1,4-dioxane (30 mL) was stirred under reflux at 70 • C for 2 h in a 100-mL round-bottom flask. oPP (2.0 g, 0.0083 mol) was added and then the mixture was heated at 110 • C for 6 h. The solution was cooled to room temperature and the solvent evaporated using a rotary evaporator.…”

“…Intra and intermolecular hydrogen bonds among their heterocyclic polymer chains impart polybenzoxazines (PBZs) with many useful properties, including high thermal stability, high glass transition temperatures, high char yields, near-zero shrinkage upon polymerization, low water absorption, low flammability, excellent mechanical and dielectric properties, low surface free energies, and high water contact angles (WCAs) [1][2][3][4][5][6][7][8][9][10]. Benzoxazine monomers, which are generally prepared through Mannich reactions of phenols, primary amines, and formaldehyde, can polymerize simply through thermal curing without any catalyst and without releasing any by-products during their ring-opening polymerization (ROP) [11][12][13][14][15][16][17][18][19][20]. Aromatic polyimides are also high-performance polymers that display high thermal stability, excellent mechanical properties, and high chemical resistance [21]; their inert imide rings and strong interchain interactions make them useful in, for example, plastics, films, laminating resins, insulating coatings, and high-temperature structural adhesives [22].…”

Segmented Polyurethanes and Thermoplastic Elastomers from Elemental Sulfur with Enhanced Thermomechanical Properties and Flame Retardancy

“…Yagci demonstrated the ability to form sulfur‐benzoxazine thermosets, which marries the world of sulfur plastic with high temperature polymers, [39] and Theato reported on sulfur‐polysilsquioxane copolymers, [40] although mechanical properties were not reported. The Yagci group also explored methods of making tunable elastomers via polydiene copolymerization with sulfur [41] . Despite these early advances, it is clear that the petrochemical and polymer industries will require the development of improved sulfur polymer chemistry and materials design to afford high performance sulfur based polymers, particularly soluble and processable thermoplastics, while achieving appreciable incorporation of sulfur into these materials using inexpensive, modular methods.…”

Segmented Polyurethanes and Thermoplastic Elastomers from Elemental Sulfur with Enhanced Thermomechanical Properties and Flame Retardancy

“…TheY agci group also explored methods of making tunable elastomers via polydiene copolymerization with sulfur. [41] Despite these early advances,i ti s clear that the petrochemical and polymer industries will require the development of improved sulfur polymer chemistry and materials design to afford high performance sulfur based polymers,particularly soluble and processable thermoplastics,w hile achieving appreciable incorporation of sulfur into these materials using inexpensive,m odular methods. Finally,itwill be desirable for sulfur-based plastics to exhibit new material properties,o rs ynergistic multi-functionality to justify utilization/deploymentv ersus conventional plastics.…”