Secondary transitions in amorphous polymers. 5. Linear form of the Tait equation applied to isotactic poly(methyl methacrylate)

1983 ◽  
Vol 16 (10) ◽  
pp. 1645-1652 ◽  
Author(s):  
Karel Solc ◽  
Steven E. Keinath ◽  
Raymond F. Boyer
Keyword(s):  
Methyl Methacrylate ◽  
Linear Form ◽  
Amorphous Polymers ◽  
Tait Equation ◽  
Poly Methyl Methacrylate ◽  
Secondary Transitions

Density Measurements of Annealed Amorphous Polymers

1995 ◽  
Vol 60 (11) ◽  
pp. 1935-1940 ◽  
Author(s):  
František Lednický
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Methyl Methacrylate ◽  
Density Measurement ◽  
Amorphous Polymers ◽  
Sufficient Accuracy ◽  
Density Measurements ◽  
Poly Methyl Methacrylate ◽  
Flotation Method

The flotation method of the density measurement was adapted to reach sufficient accuracy with which the differences due to annealing amorphous polymers above their glass transition temperature can be traced. The densities of amorphous poly(methyl methacrylate) and polystyrene increase logarithmically in the course of the annealing, which suggests that some arrangement or ordering takes place. However, the changes are not stable.

scholarly journals Additive Effects of Lithium Salts with Various Anionic Species in Poly (Methyl Methacrylate)

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4096
Author(s):  
Asae Ito ◽  
Koh-hei Nitta
Keyword(s):  
Glass Transition ◽  
Methyl Methacrylate ◽  
Lithium Ion ◽  
Amorphous Polymers ◽  
Lithium Salts ◽  
Additive Effects ◽  
Poly Methyl Methacrylate ◽  
Pmma Matrix ◽  
Molecular Scale ◽  
Anionic Species

We report that lithium salts in lithium-ion batteries effectively modify the physical properties of poly (methyl methacrylate) (PMMA). The glass transition temperature (Tg) is an indicator of the heat resistance of amorphous polymers. The anionic species of the salts strongly affected the glass transition behavior of PMMA. We focused on the additive effects of various lithium salts, such as LiCF3SO3, LiCOOCF3, LiClO4, and LiBr, on the Tg of PMMA. The large anions of the former three salts caused them to form macroscopic aggregates that acted as fillers in the PMMA matrix and to combine the PMMA domains, increasing Tg. On the other hand, LiBr salts dispersed microscopically in the PMMA matrix at the molecular scale, leading to the linking of the PMMA chains. Thus, the addition of LiBr to PMMA increased Tg as well as the relaxation time in the range of glass to rubber transition.

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