INTERACTION OF POLYMERS AND MECHANICAL WAVES 



325 



10 



111, — , 

 Z ul 

 >- OJ 

 Q > 

 CC 



lO'O ? 3 



>- 

 t Q 



H o 

 <~— 



UJ cr 



LU 



cc I- 

 V 111 



u 



(J 



ZoJ 



111 (r 

 2 < 

 Od 



cc J) 



^a. 



0.86 



DENSITY 



0.88 

 OF LIQUID 



0.92 



Fig. 6- 

 ties. 



-Principal shear elasticities of pol3'isobut3'lenes as related to their densi- 



packing of segments in the lif|iiid (coordination number, etc.) become 

 important. 



">So/r' and^^ Hard" Liquid States; Second Order Transitions 



A recent noteworthy study of vokime-temperatiu'e and viscosity- 

 temperature changes in polystyrene (with a note on polyisol)utylene) 

 brings out many points in common with ideas of polymer licjuid struc- 

 ture indicated by the dynamics work."' Particularly, the fact that 

 according to steady state measurements, the "local configurational ar- 

 rangement of the polymer segments" below Ty remains fixed accords 

 with the postulations from dynamics work. That is, above the second 

 main relaxation, it seems to be just the interactions in these fixed ar- 

 rangements which cause the glassy (or "crystalline") dynamic modulus 

 of 10 to 10 dynes/cm . Further, the point that Tg is not an isoviscous 

 state for polymers ' agrees with the dynamics result that macroscopic 



