Methacrylate comb polymers were synthesized that have amphiphilic teeth of ethylene glycol oligomers capped with alkyl groups. Both segments are of exact length to promote self-organization and crystallization. The atactic methacrylate backbone plus close proximity to the polymer backbone inhibits crystallization of the oligoethyelene oxide segments, but the terminal alkyl segments readily crystallize. Wide-angle X-ray diffraction and differential scanning calorimetry were used to characterize polymer side chain crystallization and its evolution as a function of the length of the amphiphilic teeth. An analysis of the d spacings places the oligoethylene glycol segment and the first eight carbon atoms of the alkyl chain in an amorphous phase. An similar to 1 angstrom/carbon atom increase in the d spacing is consistent with the crystalline segments being tilted relative to the polymer backbone. When the number of carbon atoms in alkyl segments is >= 14, addition of LiClO4 yields an ionic conducting ethylene oxide phase with retention of the alkyl crystallization. These novel polymer electrolytes use crystallization as a structural element to maintain dimensional stability.
BT - Macromolecules C3 -liu group
DA - 07/2006 LA - eng M1 - 14 N2 -Methacrylate comb polymers were synthesized that have amphiphilic teeth of ethylene glycol oligomers capped with alkyl groups. Both segments are of exact length to promote self-organization and crystallization. The atactic methacrylate backbone plus close proximity to the polymer backbone inhibits crystallization of the oligoethyelene oxide segments, but the terminal alkyl segments readily crystallize. Wide-angle X-ray diffraction and differential scanning calorimetry were used to characterize polymer side chain crystallization and its evolution as a function of the length of the amphiphilic teeth. An analysis of the d spacings places the oligoethylene glycol segment and the first eight carbon atoms of the alkyl chain in an amorphous phase. An similar to 1 angstrom/carbon atom increase in the d spacing is consistent with the crystalline segments being tilted relative to the polymer backbone. When the number of carbon atoms in alkyl segments is >= 14, addition of LiClO4 yields an ionic conducting ethylene oxide phase with retention of the alkyl crystallization. These novel polymer electrolytes use crystallization as a structural element to maintain dimensional stability.
PY - 2006 SP - 4726 EP - 4734 T2 - Macromolecules TI - Synthesis, structure, and ionic conductivity of self-assembled amphiphilic poly(methacrylate) comb polymers VL - 39 ER -