New polymer syntheses

Kricheldorf, Hans R.; Jonté, J. Michael

doi:10.1007/bf00262719

Cited by 13 publications

(9 citation statements)

References 13 publications

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“…In general, α-hydroxy acids are carbonylated using phosgene, diphosgene (Toyooka et al, 1989; Tang and Deng, 2002) or triphosgene (He et al, 2013; Chen et al, 2014). In case of the latter two carbonylation agents, activated charcoal is often used to promote the decomposition to phosgene and sometimes a tertiary amine (e.g., N -methylmorpholine) is added as an acid scavenger (Kricheldorf and Jont, 1983; Vandenbossche et al, 2010).…”

Section: Oca Monomer: Synthesis and Purificationmentioning

confidence: 99%

“…In early studies, the use of amines (e.g., pyridine and trimethylamine) for ROP of OCAs failed to initiate controlled polymerizations, with M n s < 3 kDa (Smith and Tighe, 1981; Kricheldorf and Jont, 1983). Besides, acidic catalysts (e.g., triflic acid) do not work for the ROP of OCAs (Martin Vaca and Bourissou, 2015).…”

Section: Organocatalyst For Oca Polymerizationmentioning

confidence: 99%

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Living Ring-Opening Polymerization of O-Carboxyanhydrides: The Search for Catalysts

Zhong

Tong

2018

Front. Chem.

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Biodegradable poly(α-hydroxy acids) can be synthesized by means of ring-opening polymerization (ROP) of O-carboxyanhydrides (OCAs). Numerous catalysts have been developed to control the living polymerization of OCAs. Here we review the rationale for the use of OCA, the desirable features for and important attributes of catalysts for the ROP of OCAs, and specific examples that have been developed.

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Section: Oca Monomer: Synthesis and Purificationmentioning

confidence: 99%

Section: Organocatalyst For Oca Polymerizationmentioning

confidence: 99%

Living Ring-Opening Polymerization of O-Carboxyanhydrides: The Search for Catalysts

Zhong

Tong

2018

Front. Chem.

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“…For sample 5 in Table 2, a glasstransition temperature of 265°C was measured with differential scanning calorimetry (DSC) at a heating rate of 20°C/min. 1…”

Section: Silylation Of Thpementioning

confidence: 99%

“…These properties include high stability against hydrolysis, high thermal stability, high stability against oxidation and UV light, low inflammability, high glass-transition temperatures, and good transparency when the PESs are amorphous. To vary their properties and broaden their applications, numerous research groups have synthesized functionalized PESs either by direct synthesis from functionalized monomers [1][2][3][4][5][6][7] or by derivatization of preformed (commercial) PESs. 8 -17 A third ap-proach consists of the preparation of star-shaped or hyperbranched PESs.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and functionalization of poly(ether sulfone)s based on 1,1,1‐tris(4‐hydroxyphenyl)ethane

Kricheldorf

Vakhtangishvili

Fritsch

2002

J. Polym. Sci. A Polym. Chem.

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Branched poly(ether sulfone)s were prepared from 1,1,1‐tris(4‐hydroxyphenyl) ethane and 4,4′‐difluorodiphenyl sulfone (DFDPS) either by polycondensation in dimethyl sulfoxide with the elimination of water or via the silyl method in N‐methylpyrrolidone. With an exact 1/1 stoichiometry, crosslinking was avoidable, but significant fractions of cyclic oligomers and polymers were detected by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. Furthermore, bridged cycles (bicycles) were detected. For the silyl method, even an excess of DFDPS of 10 mol % did not result in crosslinking. The pendant OH groups were modified by acylation with acetic anhydride, methacrylic anhydride, undecylenoyl chloride, or cinnamoyl chloride. Alkylation was only successful in a one‐pot procedure via the silyl method. Alkylbromide, ethyl bromoacetate, 3‐chloropropionitrile, 4‐nitrobenzyl bromide, and 3,4‐dichlorobenzyl chloride served as alkylating agents. With 1,3‐propane and 1,4‐butane sultone, poly(ether sulfone)s with pendant sulfonate groups were obtained. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2967–2978, 2002

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“…[1,2] Cleaner polycondensation processes may be achieved when silylated diphenols are used as monomers. [3][4][5][6][7] Clean polycondensations in combination with high conversions have the consequence that most of the reaction products have a cyclic structure.…”

Section: Introductionmentioning

confidence: 99%

Cyclic Ladder Polymers by Polycondensation of Silylated Tetrahydroxy‐tetramethylspirobisindane with 1,4‐Dicyanotetrafluorobenzene

Kricheldorf

Fritsch

Vakhtangishvili

et al. 2005

Macro Chemistry & Physics

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Summary: 5,5′,6,6′‐Tetra(trimethylsiloxy)‐4,4,4,4′‐tetramethyl‐1,1‐spirobisindane was polycondensed with 1,4‐dicyanotetrafluorobenzene under variation of solvent temperature, time, and feed ratio. Under optimized reaction conditions, all products detectable by MALDI‐TOF mass spectrometry (up to masses around 8 000 Da) proved to be cyclic ladder oligomers and polymers. In N‐methylpyrrolidone and dimethylsulfoxide odd‐numbered cycles were formed in addition to the prevailing even‐numbered ones. However, in sulfolane exclusively even‐numbered cycles were obtained (detectable up to masses around 10 000 Da), together with even‐numbered linear chains. Temperatures above 100 °C enhanced the molecular weights by side reactions. With the less reactive cyano‐2,3,5,6‐tetrafluorobenzene (CTB) again cycles were formed, but their content and the conversions were lower. Polycondensation of CTB up to 160 °C and all polycondensations of cyanopentafluorobenzene gave crosslinked products.Synthesis of cyclic ladder polymers.magnified imageSynthesis of cyclic ladder polymers.

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New polymer syntheses

Cited by 13 publications

References 13 publications

Living Ring-Opening Polymerization of O-Carboxyanhydrides: The Search for Catalysts

Living Ring-Opening Polymerization of O-Carboxyanhydrides: The Search for Catalysts

Synthesis and functionalization of poly(ether sulfone)s based on 1,1,1‐tris(4‐hydroxyphenyl)ethane

Cyclic Ladder Polymers by Polycondensation of Silylated Tetrahydroxy‐tetramethylspirobisindane with 1,4‐Dicyanotetrafluorobenzene

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