PBFB

AcronymDefinition
PBFBPast Bing/Future Bing
PBFBPrize Budget for Boys (Canada)
PBFBP-Bromofluorobenzene
References in periodicals archive ?
Samples Water absorption (wt%) [T.sub.g.sup.b] [T.sub.g.sup.b] ([degrees]C) ([degrees]C) PBFA 1.62 217 216 PBFB 1.58 >300 >300 PBFC 1.89 263 264 PB-a 0.54 163 156 PB-ala 0.61 283 278 PB-mda 0.82 238 232 [T.sub.g.sup.b], the glass transition temperature of the polyhenzoxazines before water absorption testing: [T.sub.g.sup.a], the glass transition temperature of the polyhenzoxazincs after water absorption testing.
Samples PB-a PBFA PB-ala PBFB PB-mda PBFC Static contact angle ([degrees]) 82.2 98.1 80.8 93.5 85.6 99.8 Surface energy (mN X [m.sup.-1] 40.11 29.65 43.34 37.72 37.72 28.31 From above analyses of the water absorption and hydrophobic property of two types of polybenzoxazines (BHPF type and bisphenol A type), it was found that the BHPF-based polybenzoxazines have greater free volume and better hydrophobic property than bisphenol A-based polybenzoxazines.
The corresponding polybenzoxazines show high Ts (217[degrees]C for PBFA, 263[degrees]C for PBFC, and above 300[degrees]C for PBFB, respectively), and high char yield at 800[degrees]C in [N.sub.2] (45% for PBFA, 36% for PBFB, and 55% for PBFC, respectively.).