Objective:
A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine
hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange
reaction, and free radical polymerization. Then a series of the PIL were synthesized at different
conditions.
Methods:
The specific heat capacity, glass-transition temperature and melting temperature of
the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities
of the PILs were measured by the laser flash analysis method.
Results:
Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the
thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of
421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1
K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity
λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane
thermal insulating material although the latter had a much lower density.
Conclusion:
In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously
increase the Oxygen Index, revealing its efficient flame resistance. Therefore,
P[VBTPP][PF6] is a potential thermal insulating material.
Extremely low thermal conductivity from bismuth selenohalides with 1D soft crystal structure
