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The effect of initiator‐to‐monomer ratio on the properties of the polybutadiene‐ol synthesized by free radical solution polymerization of 1,3‐butadiene
Author(s) -
Mohamad Sadeghi Gity Mir,
Morshedian Jalil,
Barikani Mehdi
Publication year - 2003
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/pi.1172
Subject(s) - polybutadiene , polymerization , monomer , polymer chemistry , molar mass distribution , radical , radical polymerization , bulk polymerization , chemistry , chain transfer , solution polymerization , solvent , polymer , copolymer , organic chemistry
Polybutadiene‐ol was synthesized by solution radical polymerization of 1,3‐butadiene in the presence of hydrogen peroxide as initiator and 2‐propanol as solvent. The ratio of initiator to monomer molar concentration, [I 0 ]/[M 0 ], was varied while temperature, reaction time and the type and amount of solvent were kept constant. The effects on the M n ; M w ; M v ; PDI, OH‐number and functionality of the synthesized polyols were studied. By taking several samples during a polymerization batch and analyzing them, the time of reaction was chosen as 100 min, after which the PDI changed dramatically. M n decreased exponentially with increasing [I 0 ]/[M 0 ] according to the relationship M n = 565.55 ([I 0 ]/[M 0 ]) −0.7553 . The decrease observed in M w gradually levelled off with increasing [I 0 ]/[M 0 ] and molecular weight distribution broadened at larger values of [I 0 ]/[M 0 ]. The OH‐number increases with [I 0 ]/[M 0 ]. In addition to the number‐average molecular weight, functionality is dependent on the number of hydroxyl‐terminated chain radicals in the reaction medium. Copyright © 2003 Society of Chemical Industry