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Heat and entropy of fusion of polypropylene
Author(s) -
Kirshenbaum I.,
Wilchinsky Z. W.,
Groten B.
Publication year - 1964
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.1964.070080618
Subject(s) - polypropylene , crystallinity , tacticity , enthalpy of fusion , fusion , thermodynamics , materials science , polymer chemistry , thermal , entropy (arrow of time) , analytical chemistry (journal) , chemistry , composite material , physics , polymer , differential scanning calorimetry , organic chemistry , philosophy , linguistics , polymerization
There are wide discrepancies in the literature values for the heat of fusion (Δ H u ) of isotactic polypropylene. A study was therefore made of the variables affecting Δ H u as determined by differential thermal analysis. The results of this study show Δ H u for 100% “crystalline” polypropylene to be 2400 cal./mole repeating unit with 2σ = 300. The entropy of fusion is 5.4 e.u./repeating unit (2σ = 0.3). Thermal history, potential errors in sample–sensor contact as well as uncertainties in x‐ray analysis for per cent crystallinity are discussed.