Polymer glycol

The polyalkylene glycol polymer employs a starter that consists of a relatively reactive alcohol and a smaller amount of its potassium or sodium salt. With propylene oxide, for instance, initiation of the polymeri2ation then involves the starter in the following steps ... 

ArOiii.iiies Aromatics Terphenyl Dipheynl Oxide Siloxane Glycol Polymer GKcnhha-.ed... 

Piehler J., Brecht A., Valiokas R., Lidberg B. and Gauglitz G., A high-density polyethylene glycol) polymer brush for immobilization on glass-type surfaces, Biosens Bioelectron 2000 15 473-481. 

Yamada, T. and Imamura, Y Simulation of continuous direct esterification process between terephthalic acid and ethylene glycol, Polym.-Plast. Technol. Eng., 28, 811-876 (1989). 

Several polymer-related uses of brassylic acid (BA) have been investigated. For example, a BA/l,3-butanediol/lauric acid oligomer is an effective plasticizer for poljrvinyl chloride,[6] BA/ethylene glycol and BA/propylene glycol polymers function as polyester based polyurethane elastomers,[7] and BA has been patented as a cross-linker for glycidyl methacrylate copolymer powder coatings.[8] However, the most detailed studies have involved polyamides selected data from these studies are summarized in Table I. 

Glycol Polymers or Polyglycols. See Ethyleneglycol Polymers, Nitrated in this vol, p E279-R... 

Sengwa, R.J., Solvent effects on microwave dielectric relaxation in poly(ethylene glycols), Polym. Int., 1998, 45, 43. 

Laser desorption Fourier transform mass spectrometry (LD-FTMS) results from a series of peptides and polymers are presented. Successful production of molecular ions of peptides with masses up to 2000 amu is demonstrated. The amount of structurally useful fragmentation diminishes rapidly with increasing mass. Preliminary results of laser photodissociation experiments in an attempt to increase the available structural information are also presented. The synthetic biopolymer poly(phenylalanine) is used as a model for higher molecular weight peptides and produces ions approaching m/z 4000. Current instrument resolution limits are demonstrated utilizing a polyethylene-glycol) polymer, with unit mass resolution obtainable to almost 4000 amu. 

Jens G (1996) Degradation of polyethylene glycol. A study of the reaction mechanism in a model molecule Tetraethylene glycol. Polym Degrad Stabil 52(3) 217-222... 

Han S, Kim C, Kwon D (1997) Thermal/oxidative degradation and stabilization of polyethylene glycol. Polymer 38(2) 317-323... 

Le Coz, C.J. and Heid, E., Allergic contact dermatitis from methoxy PEG-17/dodecyl glycol polymer (Elfacos OW 100), Contact Dermatitis, 44, 308, 2001. 

Different polyethylene glycol polymers were used in various papers and proved to be very reliable and useful for different classes of molecules their use for the synthesis of peptides [180, 181], of peptidomimetics [182] and of oligosaccharide libraries [183] was reported as the development and the use of a new PEG-linked traceless linker [184, 185], the selection of ligands for asymmetric Sharpless dihydroxylation [186-188], the use of PEG-linked triarylphosphines for LPCS requiring Mitsunobu or Staudinger conditions [189], the use of PEG-based supports to prepare a library of [l,4]oxazepine-7-ones [190] and the use of PEG-supported Schiff bases for the synthesis of a-substituted amino acids [191], Other examples of soluble polymers used for LPCS may include cellulose[192], polyacrylamide [193] polyvinyl alcohol [194, 195], various copolymers [196, 197] and NCPS [198-200]. Three excellent reviews [201-203] summarized the properties of PEG and other soluble polymers and their applications to the synthesis of peptides, oligonucleotides,... 

Boomer RM, Lewis SD, Healy JM, Kurz M, Wilson C, McCauley TG. Conjugation to polyethylene glycol polymer promotes aptamer biodistribution to healthy and inflamed tissues. Oligonucleotides 2005 15(3) 183-95. 

Graham NB, Zulfiqar M, Nwachuku NE, Rashid A (1989) Interaction of poly(ethylene oxide) with solvents 2. Water-poly(ethylene glycol). Polymer 30 528-533... 

Fig. 3. Preferential protein hydration in the presence of precipitating agents used in crystallization experiments. When high concentrations of salts are used as precipitants, a precipitant-poor layer forms near the protein (P) surface due to a higher affinity of the protein for water than for the precipitant. Other precipitants (e.g., polyethylene glycol polymers) induce formation of a similar precipitant-depleted region near the protein by solvent exclusion effects. In either case formation of the precipitant-depleted layer is energetically unfavorable. Consequently, the overall effect of precipitants is to promote molecular associations that decrease the total protein surface area exposed to solvent. After Timasheff and Arakawa (1988).

Hao, J. Deng, X. Semi-interpenetrating networks of bacterial poly(3-hydroxybutyrate) with net-poly(ethylene glycol). Polymer 2001, 42, 4091 1097. 

Table I Structural formula and molecular weight of typical polyethylene glycol polymers.

Therefore, a volatile buffer should be used if possible (e.g., ammonium acetate, ammonium nitrate). ESI-MS has been used as a detector for FFF analysis of low-molecular-weight ethylene glycol polymers [9], where the effect of different carriers on cluster formation was investigated. ESI-MS has been coupled to size-exclusion chromatography (SEC) in several applications for polymer analysis and other applications where FFF techniques can be successfully used, including proteins, neuropeptides, and DNA molecule segments. Modern ESI-MS has a broad range of flow rates from nanoliters per minute up to milliliters per minute. 

Methyl and propyl paraben Organic peroxides Phenacetin Phenolphthalein Polyethylene glycol Polymers... 

Chemical modification such as adding polyethylene glycol polymers can improve the in vivo characteristics of peptides. An example is CT-025, which is a diconjugate of recombinant salmon calcitonin (sCT).62 The chemical modification of sCT results in an orally available diconjugate that retains hormonal activity while having increased amphiphilicity. Modification can occur at sites where an amine is available. On sCT, there are sites at Cys-1, Lys-11, and Lys 18, as shown in Figure 10.1. 

Jiang, H.L. Zhu, K.J. Preparation, characterization and degradation characteristics of polyanhydrides containing poly(ethylene glycol). Polym. Int. 1999, 48, 47-52. 

PPG [Polypropylene Glycol] Abbreviated to the acronym PPG by the International Nomenclature Cosmetic Ingredient. Polypropylene glycol polymers are named as PPG-x , where x is the average number of propylene oxide (CjHgO) monomer units (e.g., PPG-10). Esters and ethers of polypropylene glycol polymers are named as PPG derivatives (e.g., PPG-10 stearate, PPG-10 lauryl ether). These compounds are generally used as emollients, emulsifiers, humectants, or surfactants. 

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