Premium
Thermal expansivity and thermal conductivity of amorphous thermoplastic polyimide and polymer liquid crystal blends
Author(s) -
Brostow Witold,
D'Souza Nandika Anne,
Gopalanarayanan Bhaskar,
Jacobs Elizabeth
Publication year - 2000
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11181
Subject(s) - materials science , polyimide , composite material , anisotropy , amorphous solid , thermal conductivity , glass transition , thermoplastic , liquid crystal , thermal expansion , thermal , polymer , thermodynamics , crystallography , layer (electronics) , optics , chemistry , physics , optoelectronics
Linear thermal expansivities α L and thermal conductivities of polyimide (TPI) and polymer liquid crystal (PLC) blends were studied. The glass transition temperatures T g of our amorphous TPI and the PLC are, respectively, 240 and 220°C. The addition of the PLC induces orientation through the channeling process, as predicted by an extension of the Flory statistical‐mechanical theory of PLCs (27). Channeling was observed at PLC concentrations as low as 5 wt%. Thermal conductivity decreases with the addition of the PLC to the TPI. The anisotropic expansivity of the blends shows a strong dependence on PLC concentration and orientation direction. The pure PLC shows a maximum on the along‐the‐flow expansivity vs. temperature curves and also negative α L values. TPI addition moves the expansivities to positive values, but the maximum persists, even for 5% PLC only.