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Melting and crystallization behavior of poly(tetrafluoroethylene). New method for molecular weight measurement of poly(tetrafluoroethylene) using a differential scanning calorimeter
Author(s) -
Suwa Takeshi,
Takehisa Masaaki,
Machi Sueo
Publication year - 1973
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1973.070171102
Subject(s) - tetrafluoroethylene , crystallization , polytetrafluoroethylene , differential scanning calorimetry , materials science , polymer chemistry , calorimeter (particle physics) , melting point , composite material , chemical engineering , analytical chemistry (journal) , polymer , chemistry , thermodynamics , chromatography , copolymer , optics , physics , detector , engineering
Melting and crystallization behavior of virgin polytetrafluoroethylene have been studied using a differential scanning calorimeter. Following quantitative relationship was found between number average molecular weight of polytetrafluoroethylene and the heat of crystallization in the molecular weight range of 5.2 × 10 5 to 4.5 × 10 7 : M̄ n = 2.1 × 10 10 Δ H c −5.16 , where M̄ n is number average molecular weight and Δ H c is the heat of crystallization in cal/g. The heat of crystallization is independent of cooling rate ranging from 4 to 32°C/min. This relationship provides a simple rapid and reliable method for measuring the molecular weight of polytetrafluoroethylene.