Effect of Diluent Content during Polymerization on Equilibrium Deformational Behavior and Structural Parameters of Polymer Network

The deformational behavior of poly(ethylene glycol monomethacrylate) which was crosslinked by ethylene glycol dimethacrylate in a concentration range c = 0.05–1.0 × 10 −4 mole/cm. 3 and polymerized in the presence of 0.05–0.75 volume parts of water was studied. The deformational behavior of these systems may be described by a two‐parameter equation. We found that the value of the constant C 2 and the content of permanent entanglements increased linearly with increasing content of polymer in the polymerizing mixture v 0 . The efficiency of crosslinking also increased and approached the theoretical value at v 0 = 1. The measured data can be expressed by the relation v = K v + Q , where v is the number of effective network chains, and K and Q are the constants depending on the crosslinking agent content, the crosslinking efficiency, and the entanglement content. On the basis of experimental data obtained it is assumed that the entanglements show partly a permanent effect and partly a labile one, the latter influencing the value of the constant C 2 .