Wendling-Suter model

Equation (11.13). In the limit of large defect excess free energy (i.e., e 0), the Wendling-Suter model (Eq. 11.13) is effectively reduced to the Baur model (Eq. 11.9). 

The Sanchez-Eby and Wendling-Suter models, which differ mainly in the limit of large e, have been successfully applied to describe experimental copolymer crystallization data, especially when counit inclusion in the crystal unit cell is substantial (i.e., e is small) [88,101]. In one such example, Marchessault and colleagues studied the isodimorphic crystallization behavior in poly(j8-hydroxybutyrate-C(9-/3-hydroxyvalerate) statistical copolymers [87, 88]. The experimentally measured copolymer melting temperatures were found to be well described by Sanchez and Eby s model with the assumptions that the crystals were of finite thickness (i.e., Eq. 11.12) and defect inclusion was uniform (i.e., Xcb = b) [88]. 

Figure 11.11 Poly(ET-c6>-EN) statistical copolymer melting temperature (T ) as a function of EN unit mole fraction Xen)-The experimental data (solid circles) are compared with different theoretical models (Flory model, gray solid line Baur model, dotted line Wendling-Suter model, black solid line, calculated with values of e/RT indicated). Reprinted with permission from Reference [101]. Copyright 1998 American Chemical Society.

Fig. 5.19 Plot of melting temperatures of ethylene terephthalate-ethylene naphthalene 2,6-decarboxylate copolymer as functions of melt composition for different theoretical models. Flory model Eq. (5.24), Baur model Eq. (5.38) composite model Eq. (5.41). Solid points experimental results(l 12,137). (From Wendling and Suter (13))...

---