Effects of High Pressure on Amorphous Polymers: Densification of Polymethyl Methacrylate

1970 ◽  
Vol 41 (7) ◽  
pp. 2917-2927 ◽  
Author(s):  
R. M. Kimmel ◽  
D. R. Uhlmann
Keyword(s):  
High Pressure ◽  
Polymethyl Methacrylate ◽  
Amorphous Polymers

Morphology of Amorphous Polymers

1968 ◽  
Vol 26 ◽  
pp. 414-415
Author(s):  
S.L. Lambert ◽  
G.S.Y. Yeh
Keyword(s):  
Thin Films ◽  
Molecular Weight ◽  
Polymethyl Methacrylate ◽  
Size Variation ◽  
Unknown Origin ◽  
Amorphous Polymers ◽  
General Concept ◽  
Polymer Molecules ◽  
Polyphenylene Oxide ◽  
Preparation Conditions

Our general concept of the amorphous morphology of polymers is that of a structureless mass of coiled and intercoiled molecules. However, replica studies of freeze-fractured rubbers, amorphous polystyrene and polymethyl methacrylate and ion-etched glassy polycarbonate often suggest the presence of nodular structures (100-1000 Å) of unknown origin. Recently a nodular ball-like structure of the order of 100 Å was also observed in thin films of amorphous polyethylene terephthalate, its appearance being due to polymer molecules tending to back fold and arranging themselves more or less parallel to one another.We have extended these studies to several other polymers including amorphous and crystallizable polystyrene and polymethyl metha-crylate, trans- and cis-polyisoprene, polyphenylene oxide, etc. and have observed similar ball-like structures (Figs. 1 and 2). The size of these structures may vary from polymer to polymer (30-100 Å), however for a given polymer no substantial size variation has been observed with respect to preparation conditions, e.g., temperature, solvent and molecular weight.

scholarly journals Testing the minimum thermal conductivity model for amorphous polymers using high pressure

2011 ◽  
Vol 83 (17) ◽  
Author(s):  
Wen-Pin Hsieh ◽  
Mark D. Losego ◽  
Paul V. Braun ◽  
Sergei Shenogin ◽  
Pawel Keblinski ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
High Pressure ◽  
Amorphous Polymers ◽  
Conductivity Model ◽  
Thermal Conductivity Model
Sign in / Sign up

Export Citation Format

Share Document