The composition of narrow distribution poly ethylene oxide-propylene oxide copolymer (Mw ~ 8700 Da) was studied using matrix assisted laser desorption ionization (MALDI) mass spectrometry. The ethylene oxide-propylene oxide copolymer produced oligomers separated by 14 Da. The average resolving power over the entire spectrum was 28,000. Approximately 448 isotopically resolved peaks representing ...

Mean-square unperturbed dimensions {r2)0 and their temperature coefficient d In{r2)0/dT have been calculated for ethylene-propylene copolymers by means of the rotational isomeric state theory of chain molecules. Conformational energies required in the analysis are shown to be readily obtained from previous analyses of polyethylene and polypropylene, without additional approximations. Results th...

We report here on the segment effects of poly(ethylene oxide)-containing block copolymers (PEO-BCP) on the reduction activity for tetrachloride gold(III) ([AuCl(4)](-)), interfacial activity for gold surface, colloidal stability, and morphology of gold nanoparticles formed in aqueous solutions. In particular, the effects of poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), polyethylene (...

copolymerization of ethylene and propylene was investigated using a 4th generation phthalate ziegler-natta catalyst in normal hexane in a buchi reactor. the effects of different mole fractions of [al]/[ti], [si]/[al] and various amounts of hydrogen on productivity and weight percent of ethylene on the product, were studied. in the copolymerization reactions, tri-isobutyl aluminum (tibal) was us...

The solubilization of hydrocarbons by micelles formed of diblock and symmetric triblock copolymers in water are compared in the framework of a mean-field theory of solubilization. The block copolymers contain poly(ethylene oxide) as the hydrophilic block and poly(propylene oxide) as the hydrophobic block and are designated as EXPYEX or EWPZ (where E and P denote ethylene and propylene oxides an...

A series of supramolecular aggregates were prepared using a poly(propylene oxide)-poly(ethylene oxide)-poly(propylene oxide) (PPO-PEO-PPO) block copolymer and β- or α-cyclodextrins (CD). The combination of β-CD and the copolymer yields inclusion complexes (IC) with polypseudorotaxane structures. These are formed by complexation of the PPO blocks with β-CD molecules producing a powder precipitat...

The use of the biocompatible amphiphilic diblock copolymer poly(ethylene glycol-b-propylene sulfide) (PEG44PPS20) allows a tuned loading of doxorubicin onto the surface of non-functionalized multi-walled carbon nanotubes and an efficient cell internalization. The obtained multi-walled carbon nanotube-based systems show enhanced cytotoxic activity with respect to non-vehicled doxorubicin.

In this study, we used diglycidyl ether bisphenol A (DGEBA) as a matrix, the ABA block copolymer poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (Pluronic F127) as an additive, and diphenyl diaminosulfone (DDS) as a curing agent to prepare flexible epoxy resins through reaction-induced microphase separation (RIMPS). Fourier transform infrared spectroscopy confirmed the existence of hydr...