Cyclic polyesters: 7. Preparation and characterization of cyclic oligomers from solution ring-chain reactions of poly(butylene terephthalate)

Bryant, Jonathan J.; Semlyen, J.A.

doi:10.1016/s0032-3861(96)01035-x

Cited by 65 publications

(37 citation statements)

References 16 publications

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“…However, equilibration by means of transesterification catalyst in high boiling inert solvents shifts the ring-chain HIGHLIGHT equilibrium totally to the side of cyclic oligoesters, due to a gain in entropy. [123][124][125][126][127][128][129] This approach allows for a rapid and simple preparation of cyclic PET or PBT oligoesters 125,127,129 and a small scale technical production has been realized.…”

Section: Theory and Technical Polymer Synthesesmentioning

confidence: 99%

Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

401

442

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Syntheses of cyclic polymers including cyclic homopolymers, cyclic block copolymers, sun-shaped polymers, and tadpole polymers are discussed on the basis of a differentiation between synthetic methods and synthetic strategies (e.g., polycondensation, ring-ring equilibration, or ring-expansion polymerization). Furthermore, all synthetic methods are classified as kinetically or thermodynamically controlled reactions. Characteristic properties of cyclic polymers such as smaller hydrodynamic volume, lower melt viscosities, and higher thermostabilities are compared to the properties of their linear counterparts. Furthermore, the nanophase separation of cyclic diblock copolymers is discussed.

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Section: Theory and Technical Polymer Synthesesmentioning

confidence: 99%

Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

401

442

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“…APCI/APPI FOR SYNTHETIC POLYMER ANALYSIS & poly(ethylene terephthalate) (Bryant & Semlyen, 1997a), the other on poly(butylene terephthalate) (PBT) (Bryant & Semlyen, 1997b). Both articles emphasized the synthesis of cyclic oligomers.…”

Section: Detection Of Species Those Are Difficult To Detect With Esimentioning

confidence: 99%

APCI/APPI for synthetic polymer analysis

Terrier

Desmazières

Tortajada

et al. 2011

Mass Spectrometry Reviews

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Modern mass spectrometry of synthetic polymers involves soft ionization techniques. Whereas matrix-assisted laser desorption/ionization (MALDI) and electrospray (ESI) are employed routinely, atmospheric pressure chemical ionization (APCI) and more recently atmospheric pressure photoionization (APPI) are used to a lesser extent. However, these latter ionization methods coupled to liquid-phase separation techniques create new opportunities for the characterization of polymers, especially for low molecular weight compounds or for the polymers that are poorly ionizable by the usual methods. After a part devoted to the description of classical MS methods employed for polymer analysis (MALDI, ESI, and their use with chromatography), APCI and APPI techniques will be described, discussed, and selected examples will present the interest of these ionization sources (or interfaces for LC/MS) in the field of polymer analysis.

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“…Recently, the cyclic formation in PET in solution was revisited by Bryant and Semlyen, 21 again with 1-methylnaphthalene and various catalysts. At a dilution of 1/10 (w/w polymer/solvent) and a catalyst concentration of 0.5 wt %, the reaction in the presence of tetraisopropyl orthotitanate gave 3 wt % of cyclics, 11 wt % with dibutyltin bis(2-ethyl hexaonate) and 20 wt % with zinc acetate.…”

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confidence: 99%