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Incompatible ternary blends based on unsaturated polyester resins. I. Phase diagrams
Author(s) -
Suspene L.,
Pascault J. P.
Publication year - 1990
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.1990.070411114
Subject(s) - prepolymer , elastomer , miscibility , materials science , spinodal , phase diagram , polymer , binodal , polymer chemistry , polyester , dispersity , ternary operation , phase (matter) , chemical engineering , composite material , chemistry , organic chemistry , polyurethane , computer science , engineering , programming language
We have determined pseudo ternary phase diagrams for blends based on unsaturated polyester resins and an elastomeric additive. Size exclusion chromatography analysis is a well‐known method for quantifying the demixed phase composition in the case of isomolecular polymers. But when some fractionation occurs, our results show that this analysis becomes inapplicable. In our systems, due to the presence of nitrogen atoms in the elastomer, elemental analysis has been used, and, with the help of the percent of styrene, this leads to the determination of the pseudo ternary phase diagrams. The major cause of this fractionation is the high polydispersity of the UP prepolymer. Lowering the molecular weight of the UP prepolymer leads to a partial miscibility with styrene. This unexpected phenomenon may be attributed to a chain‐end effect rather than a real molecular weight effect. Finally, we have defined a compatibility window between 1–3 or 1–7 phr of elastomer, where the solutions are two‐phase systems but without any sedimentation processes, even after several weeks. This compatibility window is certainly limited by binodal and spinodal curves. The higher limit, 3–7 phr of elastomer, depends strongly on the type of chain ends (hydroxyl or carboxyl) of the UP prepolymer.