ENTANGLEMENT AND EXCLUDED VOLUME EFFECTS IN RUBBER ELASTICITY

The role of interchain excluded volume and entanglement in the elastic behavior of polymeric networks is theoretically examined. A three‐chain network model is used, with each chain confined within an infinite, rectangular cylinder. The cylinders and the network crosslinks, are assumed to deform affinely. When the cross sections of the cylinders are small, the network elastic free energy equation has the form (Formula Presented.) The λs represent the macroscopic deformation ratios. The constants A, B and C are functions of the number of each type of network chain (i.e., A contains the number of tie chains; C contains the number of loops and tie chains; B contains the number of dangling chain ends, unattached chains, loops and tie chains), their unperturbed dimensions and the sizes of the cylinders which confine them. Copyright © 1979 Society of Plastics Engineers, Inc.