The invention discloses a
benzene imide structure based high-temperature self-crosslinking
copolyester with effects of
flame retardancy,
smoke suppression and melt drop resistance.
Copolyester is prepared from structural units represented by I, II and III or structural units represented by I, II and IV through random copolymerization, wherein the
characteristic viscosity [eta] of
copolyester is 0.41-1.12 dL / g, and the limit
oxygen index is 24.2%-38.7%; the vertical
combustion class is in a range from V-2 to V-0; the p-HRR (peak of heat release rate) in a cone
calorimetry test is reduced by 7.1%-72.1% as compared with that of pure PET, and total
smoke release is decreased by 2.0%-59.2% as compared with that of pure PET. The invention further discloses a preparation method of
copolyester. Ahigh-temperature self-crosslinking group introduced in the preparation process is a
benzene imide group, and prepared copolyeste cannot be subjected to crosslinking during
processing and
polymerization, so that
thermoplastic processability of
polyester is retained; meanwhile, due to the tackifying effect and high
charring property brought by the self-crosslinking action at high temperature or during
combustion, prepared copolyester has excellent
flame retardancy,
smoke suppression and melt drop resistance effects.