| Abstract
| - The interfacial properties of a three-component, two-phase A/B:Cblend are investigated tounderstand the effect of the A and B chain lengths on the interfacialexcess of B, zB*, the interfacialtension, γABC, and the interfacial width,wABC. The A/B:C components arepolystyrene/poly(d8-styrene-co-4-bromostyrene):poly(styrene-co-4-bromostyrene),where B and C have 4-bromostyrene mole fractionsof 0.154 and 0.177, respectively. Low-energy forward recoilspectrometry (LE-FRES) is used to measurezB* as a function of the B volume fraction inthe B:C blend, φB∞. The experimentalzB*'s are found to bein excellent agreement with those calculated using the self-consistentfield (SCF) model of the A/B:Cinterface. In addition, the SCF model is used to evaluateγABC and the widths for the A/B:C, A/B, andA/C interfaces (i.e., wABC,wAB, and wAC,respectively). Our results demonstrate that increasing thenumberof B segments, NB, greatly increases themagnitude of zB*, particularly at lowφB∞. On the other hand,varying NA has only a minor effect onzB*. Concurrent with the segregation of B,γABC and wAB rapidlydecrease and increase, respectively, as φB∞initially increases. Upon calculation of theentanglementlength, we, for each component,wAB is found to approachwe when φB∞ ≈0.30. As a result the mechanicalstrength of the interface should greatly improve. The optimumamount of B to achieve good compatibilization correlates with the φB∞ at whichzB* is a maximum.
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