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Study of multiple melting behaviour of syndiotactic polystyrene in β‐crystalline form
Author(s) -
Yuan Zhenhua,
Song Rui,
Shen Deyan
Publication year - 2000
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/1097-0126(200011)49:11<1377::aid-pi497>3.0.co;2-s
Subject(s) - endotherm , differential scanning calorimetry , tacticity , materials science , recrystallization (geology) , polystyrene , melting point , crystallization , annealing (glass) , polymer chemistry , thermodynamics , composite material , polymer , polymerization , paleontology , physics , biology
A series of syndiotactic polystyrene (SPS) samples in β‐crystalline form were prepared by cooling from the melt at various rates. The effects of cooling rate from the melt, DSC heating rate and annealing on the multiple melting behaviours of β crystals were investigated by differential scanning calorimetry (DSC) and temperature modulated differential scanning calorimetry (TMDSC), from which the nature of the multiple melting behaviour was determined. The two melting endotherms of β‐form crystals were considered to arise from the occurrence of simultaneous melting, recrystallization and remelting processes in the melting region. It is suggested that the lower melting endotherm is due to the melting of imperfect β crystals originally present in the sample, whereas the higher melting endotherm comes from the melting of recrystallized SPS crystals, ie more perfect β crystals that formed during the DSC scanning process. © 2000 Society of Chemical Industry