Behavior of Precision Amphiphilic Copolymers

To evaluate the affect interactions of the pendant branches could have on the behavior of these precision amphiphilic copolymers a family of similar polymers with hydroxy-terminated PEG 

Given the noticeable effect of this structural manipulation in the previous example, three polymers with different PEG branch end groups were synthesized to probe the limits of this behavior (Berda and Wagener, 2008a). In this study, the distance between the branches was held constant (branches every 21st carbon) to maximize the propensity of the backbone to crystallize in order to isolate the effects of the branches. By the same reasoning the behavior of the unsaturated version of these polymers was investigated as well (a lowercase u denotes an unsaturated backbone in the discussion below). The three polymers exhibit remarkably 

Pyrene aggregation and steric requirements result in increased Tg while only slightly altering Tm 

Short alkyl chain endgroup results in two separate crystalline regions, one from the backbone and a second from the side chains 

Long alkyl chain endgroup crystallizes with the backbone resulting in a single crystallized region 

---

Figure 10.13 Thermal behavior of precision amphiphilic copolymers featuring precise placement of methoxy terminated PEG branches.

Figure 10.15 Thermal behavior of precision amphiphilic copolymers with precisely placed amphiphilic branches simple structural modifications at the PEG branch terminus result in significant changes in behavior and morphology. (Reprinted with permission from E.B. Berda and K.B. Wagener, Inducing pendant group interactions in precision polyolefins Synthesis and thermal behavior, Macromolecules, 41, 5116-5122, 2008. 2008 American Chemical Society.)...

---