Nature of Chain Folding

If chain folding were regular and the chain stems were to lie adjacent to one another then the density would be close to that predicted from the crystal lattice 

For solution-grown single crystals of linear polyethylene, the average radius of gyration ( .s ) of the molecules is proportional to A much greater molar mass dependence of .s is observed for the polymer coil in solution, .s oc and indicates that the dimensions of the chains 

Flory based his ideas of re-entry on the tried and tested assumption that the coil follows random coil statistics in the melt. It is clear from the SANS data that the chains fold much more tightly than would be predicted by a random re-entry model.Infrared spectroscopy showed that 75% of the folds 

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