Low temperature dynamic mechanical properties of polyurethane-polyether block copolymers

1972 ◽  
Vol 12 (1) ◽  
pp. 25-29 ◽  
Author(s):  
J. L. Illinger ◽  
N. S. Schneider ◽  
F. E. Karasz
Keyword(s):  
Mechanical Properties ◽  
Block Copolymers ◽  
Low Temperature ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Temperature Dynamic

Dynamic Mechanical Properties of a Number of Elastomers and Related Polymers from 4 to 250° K

1972 ◽  
Vol 45 (4) ◽  
pp. 1033-1042
Author(s):  
R. J. Morgan ◽  
L. E. Nielsen ◽  
R. Buchdahl
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Bond Angle ◽  
Dynamic Mechanical Properties ◽  
Molecular Packing ◽  
Butyl Rubber ◽  
Monomeric Unit ◽  
Dynamic Mechanical ◽  
Young’S Moduli ◽  
Cis And Trans

Abstract Young's modulus and mechanical damping have been measured down to 4° K for cis- and trans-polybutadienes, cis- and trans-polyisoprenes, butyl rubber, and random SBR copolymers. Trans-polybutadiene has two large damping peaks below Tg, trans-polyisoprene one peak, while the cis-polymers and butyl rubber show either no damping peaks or only very small ones below Tg. The low-temperature damping peaks of the trans-polymers might be explained by a type of crankshaft motion and by a special motion of the trans-monomeric unit which involves a simultaneous vibration and bond angle deformation. The high Young's moduli of the polybutadienes compared to the polyisoprenes and the SBR copolymers are explained by the good molecular packing of the polybutadienes.

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