Cocrystallization of C24 Wax and PEB-11 Random Copolymer

49 SANS profiles from C24 solutions in d-decme at -20 °C for 0.5% (open circles) and 1% (open triangles) wax contents. The solid lines depict the power law behavior of the scattered intensity, while the dotted line represents the single wax molecule form factor in d-decane for a 0.5% wax volume fraction 

Comparing the wax solubility lines (Fig. 47) with the temperature evolution of the scattered intensity from PEB-n random copolymers in d-decane (Fig. 37) we observe that a good match of the wax and polymer aggregation tendency occurs if, e.g., small amounts of C24 wax ( 2%) are mixed with the PEB-11 copolymer, or if larger amounts of 35 wax are mixed with PEB-7.5 copolymer. In these cases a cocrystallization of wax and polymer in common structures could possibly take place. For this reason detailed SANS studies of such wax-polymer mixtures for different contrast conditions (according to Eq. 11) were done in order to elucidate the interaction mechanism taking 

The fitted form factor (dashed line) containing, in addition to Eq. 69, the asymptotic diffuse scattering from the monomer correlations within the chains (solid line) yields a thickness eff = 132 A, agreeing favorably with that from the Guinier approximation (Table 9). 

The experimental findings suggest the cocrystallization of wax with polymer. This process yields platelet structures like those cartooned in Fig. 55 where the aggregates involve a crystalline thin layer of wax and co crystallized polymer sections. Using the contrast-matching SANS results the asymptotic forward scattering from Eq. 68 may be written for each of these two embedded layers  

A joint polymer and wax platelet structure means that = x  

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