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Preparation and glass transition temperature of hyperbranched poly[allyl methyl maleate‐ co ‐ N ‐propyl maleimide]
Author(s) -
Liu Hewen,
Wilén CarlEric
Publication year - 2005
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.21958
Subject(s) - dispersity , maleimide , branching (polymer chemistry) , molar mass distribution , polymer , polymer chemistry , copolymer , glass transition , molecular mass , polymerization , materials science , kinetics , chemistry , organic chemistry , physics , enzyme , quantum mechanics
The kinetics and molecular weight averages of the hyperbranched polymers formed by the alternating copolymerization of equimolar allyl methyl maleate (AMM) and N ‐n‐propyl maleimide (PMI) were investigated. The yields, molecular weight averages, and polydispersity indices as well as the branching degrees of the produced copolymers increased with increasing initiator concentrations and prolonged polymerization time. The trends of the experimental molecular weights as determined by size exclusion chromatography were in good agreement with the theoretical predictions. The molecular weight distribution indices fit the curve given by M w / M n = 1/(1‐x D ), and the molecular weights fit the curve given by M w = 4076/(1‐x D ) 2 , where x D was the conversion of vinyl groups. DSC studies demonstrated a nonlinear relation of T g values to the reciprocal of molecular weight (M), and T g values decreased with the increase of molecular weight. For the T g values of highly branched polymers in high molecular weight range, a relation of T g = T g ∞0+ k/M was obtained, where T g ∞0was obtained by extrapolating to infinite molecular weight and k was a constant. T g ∞0was 136°C, and k = 2.9 for this work. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1941–1947, 2005