Synthesis of polyethylene oxide

Other important examples of ring-opening polymerizations are the synthesis of polyethylene oxide and the block copolymer of ethylene oxide and propylene oxide. Polyethylene oxide, also known as polyethylene glycol (PEG), is commonly produced by anionic polymerization and has a low molecular weight of less than 20,000. 

ATRP has been used to prepare AB diblock, ABA triblock, and most recently ABC triblock copolymers (17). To date, the techniqne has been used to create block copolymers based on polystyrene and varions polyacrylates (16). However, it is possible to synthesize a so-called macroinitiator by other polymerization mechanisms (anionic, cationic, etc), and nse this in the ATRP of vinyl monomers. Examples, such as the anionic polymerization of PEG macroinitiators for ATRP synthesis of polyethylene oxide/polystyrene block copol5uners, are discussed in Reference 16. 

Synthesis of Polyethylene Oxide Diphosphate Ester. To a solution of 0.06 moles of phosphorus oxychloride in 100 ml of dry carbon tetrachloride in a three necked flask, was added 0.05 moles of polyethylene glycol in 50 ml of dry carbon tetrachloride. After the addition was complete, the rest of the procedure was the same as that followed for the monophosphate. 

Synthesis of polyethylene and polypropylene Eischer-Tropsch synthesis Oxidation of SO2 to SO ... 

The three isomers constituting n-hutenes are 1-hutene, cis-2-hutene, and trans-2-hutene. This gas mixture is usually obtained from the olefinic C4 fraction of catalytic cracking and steam cracking processes after separation of isobutene (Chapter 2). The mixture of isomers may be used directly for reactions that are common for the three isomers and produce the same intermediates and hence the same products. Alternatively, the mixture may be separated into two streams, one constituted of 1-butene and the other of cis-and trans-2-butene mixture. Each stream produces specific chemicals. Approximately 70% of 1-butene is used as a comonomer with ethylene to produce linear low-density polyethylene (LLDPE). Another use of 1-butene is for the synthesis of butylene oxide. The rest is used with the 2-butenes to produce other chemicals. n-Butene could also be isomerized to isobutene. ... 

The chemical and physical properties of the polymers obtained by these alternate methods are identical, except insofar as they are affected by differences in molecular weight. In order to avoid the confusion which would result if classification of the products were to be based on the method of synthesis actually employed in each case, it has been proposed that the substance be referred to as a condensation polymer in such instances, irrespective of whether a condensation or an addition polymerization process was used in its preparation. The cyclic compound is after all a condensation product of one or more bifunctional compounds, and in this sense the linear polymer obtained from the cyclic intermediate can be regarded as the polymeric derivative of the bifunctional monomer(s). Furthermore, each of the polymers listed in Table III may be degraded to bifunctional monomers differing in composition from the structural unit, although such degradation of polyethylene oxide and the polythioether may be difficult. Apart from the demands of any particular definition, it is clearly desirable to include all of these substances among the condensation... 

Fig. 22 Images and data representing development and application of DLS on a chip a one iteration in the design of a microfluidic DLS fabricated from aluminum with the surface anodized black to reduce surface reflections b image of a microfluidic chip that integrates polymer synthesis with DLS. The machined channels have been covered by a Kapton sheet fixed with adhesive c data for temperature depended micelle formation of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (Pluronic P85) at 2% by volume in water. (Derived from [106] with permission)...

We synthesized [13] IPNs composed of polyethylene oxide) (PEO) (polymer A) and poly(N-acryloylpyrrolidine) (PAPy) (polymer B). The IPN was synthesized by simultaneous crosslinked polymerization of APy and PEO. The overall reaction scheme for IPN synthesis by radical polymerization for APy (polymer A) and addition polymerization for PEO (polymer B) is shown in Fig. 3. This pair shows simple coacervation behavior in water. The IPN is constructed from PEO and PAPy networks as shown in Fig. 4. Chemically independent networks of polymer A and polymer B are interlocked and macroscopic phase separation in water swollen states is avoided. 

SYNTHESIS OF CERIUM OXIDE NANOPARTICLES IN POLYETHYLENE MATRIX... 

Ethylene (Ethene) (bicarburetted hydrogen, ethene) n. A colorless, flammable gas derived by cracking petroleum and by distillation from natural gas. In addition to serving as the monomer for polyethylene, it has many uses in the plastics industry including the synthesis of ethylene oxide, ethyl alcohol, ethylene glycol (used in making alkyd and polyester resins), ethyl chloride, and other ethyl esters. Properties molecular weight, 28 bp, — 1.025°C Sp gr of liquid, 0.610/0°C. 

Details are given of the synthesis of novel reverse thermo-re.sponsive polymeric systems by the polymerisation of polyethylene oxide and polypropylene oxide segments. Data are presented concerning the size of aggregates... 

Dimethylfuran and acrolein are products of degradation of biomass such as cellulose. They were used as starting materials in the synthesis of p-xylene, demonstrating the utilization of materials obtainable from biomass toward the synthesis of polyethylene terephthalate (Scheme 16.31) [33]. The key steps involve Lewis acid-catalyzed eyeloaddition followed by oxidation and further aromatization through acid-mediated dehydration. 

Measurement of Ionic Conductivity. The synthesis of solvent-free metal salt complexes of polyethylene oxides prompted detailed electrical measurements with the thought that these materials might prove to be useful electrolytes, in a hydrous environment, for high energy density batteries (13-15). Many fundamental properties of these polymer electrolytes have been examined and a large literature on the subject is available (16-17). We prepared a disk of one of our polyether complexes and measured its conductivity by impedance methods. 

Isoxazolmes are good preciusors of a,fi-unsatiuated ketones.This transformadon ii nsefid for synthesis of polyenes. For example, nitnle oxide cycloaddidon chemistry is used tc prepare4-oxo-2-alkenylphosphonates, which are useful to synthesize a long polyethylenic unii via Woodworth-Errunons olefinadon fEq. 8.66. ... 

Synthesis of comb (regular graft) copolymers having a PDMS backbone and polyethylene oxide) teeth was reported 344). These copolymers were obtained by the reaction of poly(hydrogen,methyl)siloxane and monohydroxy-terminated polyethylene oxide) in benzene or toluene solution using triethylamine as catalyst. All the polymers obtained were reported to be liquids at room temperature. The copolymers were then thermally crosslinked at 150 °C. Conductivities of the lithium salts of the copolymers and the networks were determined. 

Ethene is used as a starting material for the synthesis of many industrial compounds, including ethanol, ethylene oxide, ethanal (acetaldehyde), and polyethylene (PE). 

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