Thermal conductivity of polyacetylene

Abstract

The thermal conductivity of polyacetylene has been measured in the temperature range of 0.8 to 300 K. For T<70 K we present also data of AsF5-doped samples and of doped samples which have been compensated with (CH3)2NH into the insulating state. The undoped sample shows a T2-temperature dependence up to 12 K followed by a decreasing power law at higher temperatures and a thermal conductivity value of 4 mW/K cm at room temperature. Doping and even compensating increases the thermal conductivity below 12 K. This additional conductivity is therefore explained by a change in the phonon boundary scattering at the interfaces between crystalline and amorphous regions of polyacetylene and not by a contribution of charge carriers to the thermal conductivity.

Thermal Transport in Conductive Polymer–Based Materials

“…This is most probably due to the dominating thermal radiation between the samples and environment that is not separated experimentally. Later, Moses and Denenstein and Schweizer et al modified the steady‐state method and measured the thermal conductivity of PA to be a reasonable value. The thermal conductivity of undoped cis ‐(CH) x and trans ‐(CH) x is measured to be around 0.21 and 0.38 W m −1 K −1 , respectively.…”

“…a) Thermal conductivity of undoped, doped and orientated (CH) x . Reproduced with permission . Copyright 1984, AIP Publishing LLC and Copyright 1989, Elsevier.…”

“…The value is measured to be 20-250 times larger than that of typical bulk saturated polymers, and a strong temperature dependence is observed when temperature is higher than 100 K. [74][75][76] This is most probably due to the dominating thermal radiation between the samples and environment that is not separated experimentally. Later, Moses and Denenstein [77] and Schweizer et al [43] modified the steady-state method and measured the thermal conductivity of PA to be a reasonable value. The thermal conductivity of undoped cis-(CH) x and trans-(CH) x is measured to be around 0.21 and 0.38 W m −1 K −1 , respectively.…”

“…In conducting polymers, solitons, polarons and bipolarons are major charge carriers, unlike the case in metals. Figure 2a shows the measured thermal conductivities of undoped PA, 2.5% doped PA, and 12% doped PA [43] and orientated PA. [44] The temperature-dependent thermal conductivity of inorganic crystals has been well explained by the increase of the specific heat at low temperatures (κ ∝ T 3 ). However, the case of amorphous materials is different.…”

Reducing thermal transport in electrically conducting polymers: Effects of ordered mixing of polymer chains

“…The thermal conductivities of PANI and PA also increase below T g with increasing temperature because of enhanced specific heat. 22,23 Figure 3 presents the variation of j pn and j p PANI for configurations 1 and 4, described in the supplementary material, 13 at different temperatures. j p PANI increases with temperature up to 300 K and then slightly decreases close to T g (493 K), suggesting an increase in phonon scattering from emerging defects in form of voids.…”