Analysis of the Adequacy of the Representation of Entanglement Effects by Chain Loops

It is generally considered that polymer chains are intertwined or “entangled” – because they cannot penetrate each other – and that these entanglements are responsible for melt elastic properties. There is no physical definition of entanglement. They are considered to be binary interactions between polymer chains and represented with the looping picture or by slip‐links. The interaction energy of chain loops and of two Kuhn monomers is evaluated for several polymers. It is lower than the melt thermal energy, implying that chain loops or any other binary interactions between chain segments cannot account for the properties assigned to entanglements.