The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene ph...

The temperature and pH dependent self-assembly of three star shaped ethylene oxide-propylene oxide (EO-PO) block copolymers (Tetronics® 304, 904 and 908) with widely different hydrophobicity was examined in aqueous solutions. Physico-chemical methods viz. viscosity, cloud point, solubilization along with thermal, scattering and spectral techniques shows strongly temperature and salt dependent s...

We report on a ternary isothermal system consisting of a poly(ethylene oxide)/poly(propylene oxide) (PEO/PPO) amphiphilic block copolymer, “water”, and “oil” (where “water” and “oil” are selective solvents for the different blocks), which exhibits the richest structural polymorphism ever observed (in equilibrium) inmixtures containing amphiphiles (such as block copolymers, surfactants, or lipid...

Size exclusion chromatography (SEC) is a technique routinely used at high temperature to analyze the molar mass distribution (MMD) in polymers. The of comonomer along axis copolymer key microstructural feature that determines macroscopic properties material and thus its range possible applications. However, unsaturated polymers requiring dissolution temperature, measurement chemical composition...

BACKGROUND Drug and contrast agent delivery systems that achieve controlled release in the presence of enzymatic activity are becoming increasingly important, as enzymatic activity is a hallmark of a wide array of diseases, including cancer and atherosclerosis. Here, we have synthesized clusters of ultrasmall superparamagnetic iron oxides (USPIOs) that sense enzymatic activity for applications ...

Series of ethylene/1-alkene and ethylene-propylene-diene copolymers are separated with size exclusion chromatography (SEC) at 150°C using 1,2,4-trichlorobenzene as the mobile phase. Methyl (CH3–) methylene (–CH2–) groups in polymer samples monitored specific wavelengths via a filter-based infrared detector (IR5). It is found that ratio CH3/CH2 may increase, be constant, decrease or change irreg...

This study aims to hydrophilize thermoplastic polyurethane (TPU) surface via selective segregation of amphiphilic block copolymers from bulk TPU matrix, namely “inverted grafting-to” approach. To this end, hydrophilic poly(ethylene glycol) (PEG) polymer chain was employed in either diblock (polycaprolactone-b-poly(ethylene (PCL-b-PEG)) or triblock (poly(ethylene glycol)-b-poly(propylene glycol)...