Tacticity-dependent cross-plane thermal conductivity in molecularly engineered amorphous polymers

Autor:	Min Sang Kwon, Shalik Ram Joshi, Gun-Ho Kim, Jaekyo Lee, Youngmu Kim
Rok vydání:	2021
Předmět:	chemistry.chemical_classification Materials science Polymers and Plastics Organic Chemistry Bioengineering Polymer Biochemistry Amorphous solid Viscosity chemistry.chemical_compound Thermal conductivity chemistry Chemical engineering Methacrylic acid Tacticity Elastic modulus Acrylic acid
Zdroj:	Polymer Chemistry. 12:975-982
ISSN:	1759-9962 1759-9954
Popis:	The low thermal conductivity of polymers impedes heat dissipation in plastic products and often limits their functionality and reliability. Extended polymer chain conformation (i.e., planar zigzag) has widely been found to enhance heat transfer in both a single polymer chain and bulk polymers. Here, we show that the tacticity of polymers (poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA)) significantly affects the thermal conductivity of ionized polymers, in which the extended chain conformation is induced by electrostatic repulsion. Depending on their tacticity, polymers with similar degrees of ionization were observed to have significantly different thermal conductivities, as high as 1.14 W m−1·K−1 in ionized atactic PAA and 0.69 W m−1·K−1 in ionized syndiotactic PMAA, but only 0.55 W m−1·K−1 in ionized isotactic PAA and 0.48 W m−1·K−1 in ionized isotactic PMAA. The elastic modulus, degree of ionized carboxyl groups, and viscosity data suggest that the size and spatial arrangement of side groups, which influence the conformation of the polymer chain, affect the thermal conductivity of polymers.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::01b367bb83a936206c462a051e70d8a7 https://doi.org/10.1039/d0py01549k Zobrazit plný text záznamu