Polymerization ring-opening process

The ring system 13.18 (R = Cl) is a source of hybrid PN/SN polymers containing three-coordinate sulfur via a ring-opening polymerization process. This polymerization occurs upon mild thermolysis at 90°C (Section 14.4)." ... 

The cation [NSO(NPCl2)2] (14.11) is the proposed intermediate in this ring-opening polymerization process. This cation is extremely reactive, as illustrated by the isolation of the solvent-derived product 14.12 when it is generated by halide abstraction from the cyclic precursor with AICI3 in l,2-dichloroethane. °... 

Process III Preparation of Polyphosphazenes by Ring Opening Polymerization Processes of Substituted or Partially Substituted Cyclophosphazenes... 

Formation of polymer chains or networks from these compounds can be conceived either as a ring-opening polymerization process or a polyreaction involving exo-cyclic functional groups. 

K. Ohkita, T. Imamura, and N. Oshima, Cycloolefin copolymer formed by ring-opening polymerization, process for producing the same, and optical material, US Patent 7056999, assigned to JSR Corporation (Tokyo, JP), June 6,2006. 

The simultaneous hydrosilylation and ring-opening polymerization process provides a powerful method for the construction of a variety of novel polymer networks including comb, block and graft polymers, e.g. 272 (equation 102)271. 

Lactic acid is produced from corn by fermentation. Relatively small PLA polymers are produced next, and then broken down into dimers (lactide). These lactic acid dimers are then polymerized in a ring-opening polymerization process, yielding high molecular weight PLA, as shown in Fig. 4.9. 

Wang also prepared compound 45 in which two UPy units are connected with a photochromic dithienylethene unit [112]. It exists as a cyclic monomer at low concentrations and undergoes concentration-dependent ring-opening polymerization process (Fig. 1.13). To explore the potential applications of the supramolecular polymer, a small amount of mono-UPy-terminated fluorescent dye FI was added to a solution of 45 to end-cap the linear polymer and then the mixture was spin coated to fabricate a smooth mixed film. The closed form of the diarylethene can absorb... 

The molar mass values resulting from step-growth or ring-opening polymerization processes depend solely on the extent of reaction (p) and, since they follow a Flory distribution at any p, low mass oligomers should be absent for values of p close to unity. 

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