Effect of end group and solvent on gel permeation chromatography of oligo(oxyethylene) compounds

Amphiphilic Water Soluble Triblock Copolymers Based on Poly(2,3-dihydroxypropyl methacrylate) and Poly(propylene oxide): Synthesis by Atom Transfer Radical Polymerization and Micellization in Aqueous Solutions

“…Because of the bulky acetonide ring the hydrodynamic volumes of both polymers at the same molar masses are presumably too different. Large disagreements between GPC and 1 H NMR measurements in similar situations have been reported before. , Moreover, it is also possible that inside the GPC column additional effects, such as partitioning, were present besides the desired size exclusion separation mechanism . Furthermore, it is uncertain that THF is a completely nonselective solvent for both of the blocks (PDMM and PPO).…”

“…9,16 Moreover, it is also possible that inside the GPC column additional effects, such as partitioning, were present besides the desired size exclusion separation mechanism. 33 Furthermore, it is uncertain that THF is a completely nonselective solvent for both of the blocks (PDMM and PPO). Thus, the elution behavior of the block copolymers may strongly depend on composition.…”

Synthesis of Discrete Mass Poly(butylene glutarate) Oligomers

“…As shown in Scheme 3, orthogonal deprotection of fully protected oligomers (9, 10, 11, 12) yielded the FMOC-protected (9A, 10A, 11A, 12A) and the 4-methoxybenzyl-protected (9B, 10B, 11B, 12B) oligomers. Subsequent molecular doubling using EDCI/DMAP coupling of copolymers of the same degree of polymerization yielded orthogonally protected products (10,11,12). Removal of FMOC with 5% TEA from fractions of the protected acids (8A, 9A, 10A, 11A, 12A) produced the unprotected synthetic target copolymers (8C, 9C, 10C, 11C, and 12C) with 4, 8, 16, 32, and 64 structural units, respectively.…”

“…Stepwise synthesis has been applied to the production of pure oligopeptides and has yielded compounds containing up to 175 chain atoms . Pure oligomers of polyurethanes, − poly(ethylene glycol), − and biodegradable oligo(ester amides) have also been prepared in a similar manner. Linear oligomers of poly(hydroxy butyrate) (P(3-HB)) containing up to 96 3-HB units have been produced using an exponential segment-coupling strategy …”

“…1 FMOC-Protected Butylene Glutarate 64-mer (12A). In an 25 mL Erlenmeyer flask, 12.0 mg (2.0 µmol) of fully protected butylene glutarate 64-mer (12) was stirred in a 5% TFA in 15 mL of CH2Cl2 for 2 h. The reaction mixture was extracted 3 × 25 mL of H2O, and the organic phase was dried by rotary evaporation and vacuum-drying overnight. The pure product was isolated by precipitation with 50 mL of ether from 2 mL of CH 2Cl2 and recrystallization using 50 mL of ethanol [yield: 9.8 mg (82.5%)]; waxy solid.…”