Effect of copolymer composition and conversion on the glass transition of methyl acrylate–methyl methacrylate copolymers

Abstract

The glass transition of methyl methacrylate methyl acrylate copolymers over a wide range of conversion and sequence distribution have been analyzed with the only purpose of predicting the change in the glass transition in copolymers as a function of conversion and consequently of comonomer sequence distribution. © 1994 John Wiley & Sons, Inc.

Glass transition temperatures of butyl acrylate-methyl methacrylate copolymers

“…It is apparent that the glass transition temperature depends on the chemical structure, and it decreases with lowering chain length as a result of higher flexibility and increasing molecular motion. 20 Likewise, the average T g of MA-MMA copolymers 16 is higher (T g ϭ 345.4 K) than the value obtained from experimental data. This has been seen in other systems.…”

“…In addition to this, a previous study has demonstrated that the MA-MMA copolymers, 16 obtained under the same conditions, behave similarily. The T g12 for this copolymer is 304.3 K (r MA ϭ 0.42 and r MMA ϭ 2.36), which is slightly higher than for BA-MMA copolymers , because of less flexibility in the MA-MMA chain.…”

“…Among all of these, the ones derived by Johnston, Barton, or Couchman, which correlate T g to the dyad distribution in the instantaneous copolymer molecules, have better agreement with experimental T g 's. 16,17 In this work, we use Johnston's equation, which is based in the free volume concept and the inter-intramolecular composition of the copolymer. The description of Johnston's model follows.…”

Statistical Glycopolymers Based on 2‐Hydroxyethyl Methacrylate: Copolymerization, Thermal Properties, and Lectin Interaction Studies

“…The presence of a single glass transition temperature in the statistical glycopolymers is easily distinguished and it appears at temperatures between the T g of the individual homopolymers. The glass transition temperature of PMA is −8.0 °C, which is similar to that found in the literature 36. The T g of PHEMAGl is 126 °C, is higher than its former polymer, poly(2‐hydroxyethyl methacrylate) PHEMA, with a value around 99 °C 37–40.…”

Glass Transition Temperatures of Poly[(methyl methacrylate)-co-(butyl acrylate)]s Synthesized by Atom-Transfer Radical Polymerization

“…It has been pointed out that the Johnston, [15] Barton [16] and Couchman [17] models are the most complete ones to predict T g s of copolymers as a function of their monomer composition and sequence distribution. [22,23] However, these models are based on the assumption that the copolymer molecular weights are large enough to have reached the plateau where the properties remain constant. In this sense, the first analysis will be to find out whether or not the molecular weight of the copolymers synthesized by means of ATRP can affect T g .…”