The concept of cohesional entanglement

Abstract A concept of cohesional entanglement through local nematic interaction of neighboring chain segments has been introduced in addition to the usual topological entanglement of chains. As topological entanglement is important to properties of the polymer in the rubbery and flowing states at temperatures well above its T g , the cohesional entanglement is important to properties at temperatures around and below T g . Evidences for the existence of cohesional entanglements are presented. From the point of view of cohesional entanglement the DSC curves of glass transition and the effect of sub‐Tg annealing are discussed. Finally the stress peak on yielding during uni‐axial drawing, rejuvenation of sub‐T g annealed polymer by drawing and anti‐plasticization of plastics are discussed based on the concept of cohesional entanglement.