1.IR-ATR chemical sensors based on planar silver halide waveguides coated with an ethylene/propylene copolymer for detection of multiple organic contaminants in water.
Lu R1, Sheng G, Li W, Yu H, Raichlin Y, Katzir A, Mizaikoff B. Angew Chem Int Ed Engl. 2013 Feb 18;52(8):2265-8. doi: 10.1002/anie.201209256. Epub 2013 Feb 1.
2.Sequencing of specific copolymer oligomers by electron-capture-dissociation mass spectrometry.
Cerda BA1, Horn DM, Breuker K, McLafferty FW. J Am Chem Soc. 2002 Aug 7;124(31):9287-91.
Although a poly(ethylene/propylene glycol) (PEG/PPG) copolymer mixture is far too complex (approximately 150 oligomeric formulas) for conventional purification, oligomer ion compositions of <1% abundance can be separated by Fourier transform mass spectrometry and dissociated into sequence-specific fragment ions. Using collisionally activated dissociation (CAD) or other conventional energetic methods, we found that misleading rearrangements are common; however, these are negligible with electron capture dissociation (ECD), consistent with its nonergodic mechanism. Despite the lack of reference compounds, ECD of five oligomers ranging from PEG(1)PPG(18) to PEG(9)PPG(15) shows that approximately 80% of their isomers have all PEG units at one end, while CAD gave lower values because of an approximately 21% rearrangement loss of internal monomer units. In contrast to the indicated triblock "PEG/PPG/PEG" sample designation of this commercial surfactant, all of these oligomers are found to consist primarily of diblock PEG/PPG structures, so that their termini differ significantly in hydrophobicity, as expected for a surfactant.
3.Stability of tranexamic acid in 0.9% sodium chloride, stored in type 1 glass vials and ethylene/propylene copolymer plastic containers.
McCluskey SV1, Sztajnkrycer MD, Jenkins DA, Zietlow SP, Berns KS, Park MS. Int J Pharm Compd. 2014 Sep-Oct;18(5):432-7.
Tranexamic acid has recently been demonstrated to decrease all-cause mortality and deaths due to hemorrhage in trauma patients. The optimal administration of tranexamic acid is within one hour of injury, but not more than three hours from the time of injury. To aid with timely administration, a premixed solution of 1 gram tranexamic acid and 0.9% sodium chloride was proposed to be stocked as a medication in both the aeromedical transport helicopters and Emergency Department at Mayo Clinic Hospital--Rochester Saint Marys Campus. Since no published stability data exists for tranexamic acid diluted with 0.9% sodium chloride, this study was undertaken to determine the stability of tranexamic acid diluted with 0.9% sodium chloride while being stored in two types of containers. Stability was determined through the use of a stability-indicating high-performance liquid reverse phase chromatography assay, pH, and visual tests. Tranexamic acid solutions of 1 gram in 0.
4.Ethylene/propylene copolymerization catalyzed by vanadium complexes containing N-heterocyclic carbenes.
Zhang S1, Zhang WC, Shang DD, Zhang ZQ, Wu YX. Dalton Trans. 2015 Sep 14;44(34):15264-70. doi: 10.1039/c5dt00675a.
Various vanadium complexes containing N-heterocyclic carbenes, VOCl3[1,3-R2(NCH=)2C:] (V1, R = 2,6-Me2C6H3; V2, R = 2,6-Et2C6H3; V3, R = 2,6-(i)Pr2C6H3; V4, R = 2,4,6-Me3C6H2), have been synthesized and employed as catalyst precursors for ethylene/propylene copolymerization after activation by Et3Al2Cl3. Complex V4 showed higher catalytic activity of ca. 38 kg copolymer per (mol of V) per h and an ethylene/propylene copolymer with random monomer distribution could be prepared. Complex V3 consumed more cocatalyst than its analogues to reach higher catalytic activity. The obtained copolymers exhibit relatively narrow polydispersity and contain more randomly distributed monomer units than that the copolymers prepared by using the traditional vanadium catalytic system.