Effects of Complexation on the Glass Transition Temperature of Polymers

1990 ◽  
Vol 215 ◽  
Author(s):  
Michael F. Roberts ◽  
Samson A. Jenekhe
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Hydrogen Bonds ◽  
Intermolecular Interactions ◽  
Lewis Acid ◽  
Dominant Effect ◽  
Intermolecular Hydrogen Bonds ◽  
Aromatic Polyamides ◽  
Rigid Chain

AbstractThe effects of Lewis acid complexation on the glass transition temperature (Tg) of several polymers with strong intermolecular interactions was investigated. The decrease in the Tg due to GaCl3 complexation of aliphatic and aromatic polyamides was 40–600° C and 148° C, respectively, and was shown to originate from scission of the intermolecular hydrogen bonds. The reduction in the Tg due to GaCl3 complexation of rigid–chain polymers was greater that 325° C and can be explained by the mitigation of the otherwise strong van der Waals forces in the pristine polymers. Thus, the dominant effect of intermolecular interactions on the Tg of several polymers has been probed by Lewis acid complexation.

Study of the Behavior of Some Polyheteroarylenes Treated with Supercritical Carbon Dioxide

2009 ◽  
Vol 21 (5) ◽  
pp. 562-578 ◽  
Author(s):  
Inga A. Ronova ◽  
Lev N. Nikitin ◽  
Ekaterina A. Sokolova ◽  
Ion Sava ◽  
Maria Bruma
Keyword(s):  
Carbon Dioxide ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Supercritical Carbon Dioxide ◽  
Hydrogen Bonds ◽  
Polymer Matrix ◽  
Residual Solvent ◽  
Before And After ◽  
Supercritical Carbon

Various polyheteroarylenes have been studied with regard to their physical properties before and after treatment with supercritical carbon dioxide (sc-CO 2). Thus, the study of dependence of glass transition temperature and free volume of polymer matrix on the conformational rigidity showed that the process of swelling in sc-CO2 is influenced by the residual solvent and by the formation of possible hydrogen bonds between CO2 and amide groups in the polymer chain.

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