138 



THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1952 



lO^xiS 





lolO 



" 2 



a >: 9 



5^8 



o ?! 4 



•-9 



*^^ 3 



°f 2 



2 ;?5 



I- o 

 < o 1 



10 20 30 40 50 60 10 20 30 40 50 60 



TEMPERATURE IN DEGREES CENTIGRADE 



Fig. 12 — Shear stiffness, series viscosity and molecular viscosity plotted as a 

 function of temperature for two molecular weight solutions of polyisobutylene 

 in cyclohexane. 



0.3 - 



<?• 

 u. 

 O 



O MEASURED POINTS 

 STATIC VALUE OF 

 = 0.269 POISE 



ff, 



10^ = 10* = 10= ^ 10^ 



FREQUENCY IN CYCLES PER SECOND 



100 X 10^ 



Fig. 13 — 'Shear elasticity for a one per cent solution of polyisobutylene as a 

 function of frequency for 25°C. 



