Synthesis and characterization of a novel siloxane‐imide‐containing polybenzoxazine

Abstract

A novel siloxane-imide-containing polybenzoxazine based on N,N -bis(N-phenyl-3,4-dihydro-2H-benzo[1,3]oxazine)-5, 5 -bis(1,1 ,3,3 -tetramethyldisiloxane-1,3-diyl)-bis(norborane-2,3-dicarboximide) (BZ-A1) was successfully synthesized. The thermal properties of BZ-A1 are superior to those of conventional polybenzoxazines lacking siloxane groups. Polymerized BZ-A1 possesses extremely low surface free energy (γ s = 15.1 mJ m −2 ) after curing at 230 • C for 1 h. Moreover, the surface free energy of polymerized BZ-A1 is more stable than conventional bisphenol A-type polybenzoxazine during thermal curing and annealing processes, indicating that polymerized BZ-A1 is more suitable for applications requiring low surface free energy materials for high temperatures over long periods of time.

Structurally diverse benzoxazines: synthesis, polymerization, and thermal stability

“…The curing parameters derived from ( Figure 6) are compiled in (Table 1). The BAB [18] starts to cure at 163°C and ends at 304°C, with the cure maximum at 229°C. And the associated heat of enthalpy of cure reaction for BAB is 273 J/g.…”

“…[10,17] Recently, lot of work is being done in the field of polybenzoxazine. Chen et al [18] studied polybenzoxazines containing siloxane and imide group. Santhosh Kumar et al [19] studied polybenzoxazines containing different cyclohexyl moieties and reported that the char yield is proportional to the aromatic content of the polymer.…”

Silane‐functional benzoxazine: synthesis, polymerization kinetics and thermal stability

“…Thus, introducing the sulfone moiety into benzoxazine can enhance the rigidity, modulus and thermal stability of the corresponding cured resins . Another important way of enhancing the performance is to fabricate inorganic − organic hybrids of polybenzoxazine with polysiloxane, which could improve its flexibility, thermal stability (in terms of initial decomposition temperature and char/ceramic yields) and flame retardancy and increase its glass transition temperature . Moreover, the hydrogen bonds formed in the benzoxazine ring‐opening process favour the arrangements of organic fragments of the polysilsesquioxanes .…”

Dynamic mechanical and shape memory properties of polybenzoxazines based on aminopropyl‐terminated siloxanes

“…In practice, many researchers incorporate flexible SiOSi linkages into benzoxazine molecules to improve the processability and brittleness of polybenzoxazines, and various siloxane‐containing benzoxazines were synthesized from 1,3‐bis(3‐aminopropyl)tetramethyldisiloxane, 3‐aminopropyltriethoxysilane, α,ω‐bis(aminopropyl)polydimethylsiloxane, siloxane‐containing dihydroxyl compounds, and γ‐aminopropyldimethoxy‐methylsilane and dimethyldiethoxysilane, or from hydrosilylation reaction of allyl‐containing benzoxazines with 1,1,3,3‐tetramethyldisiloxane and hydride terminated polydimethylsiloxane . These works incorporated different siloxanes into benzoxazines, which enhance the properties of the resultant polybenzoxazines, such as glass transition temperature ( T g ) and toughness, thermal stability, flame retardancy, surface hydrophobicity, elongation at break, and flexibility, but they did not involve the research on SME for polybenzoxazines.…”