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Thermal properties and side chain crystallinity of styrene and n ‐alkyl methacrylate terpolymers
Author(s) -
Karažija Tomislav,
Vidović Elvira,
Jukić Ante
Publication year - 2013
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.23599
Subject(s) - crystallinity , materials science , copolymer , methacrylate , differential scanning calorimetry , methyl methacrylate , glass transition , styrene , polymer chemistry , polymer , chemical engineering , composite material , physics , engineering , thermodynamics
Differential scanning calorimetry method was used for the study of thermal properties of terpolymers of styrene (ST) or methyl methacrylate (MMA) with dodecyl methacrylate and octadecyl methacrylate. Particularly, the interdependencies of the crystallinity content and composition of terpolymers were examined. The increase of the MMA or ST content in terpolymers resulted in the increased glass transition temperatures and decrease of the ratio of crystalline relative to amorphous phase (from 10% for x MMA = 10 mol% to 5.7% for x MMA = 30 mol%, and from 8.5% for x ST = 16 mol% to 4% for x ST = 40 mol%). These kinds of copolymers are commonly used as flow improvers at low temperatures for lubricating mineral oils; therefore a direct correlation between flow behavior of polymer solutions in mineral oil (pour point) and side‐chain crystallinity of copolymers was examined. Thus, by increasing the proportion of crystalline phases, i.e. the long‐chain alkyl methacrylates in copolymer, the pour point of oil solutions lowers. Thus, the solution of terpolymer with crystalline phase content of 4 mol% displays the pour point of −9°C while in those with crystalline phase content higher than 7 mol% pour point lowers below −30°C. POLYM. ENG. SCI., 53:2299–2307, 2013. © 2013 Society of Plastics Engineers