Differences and similarities between mono-, bi- or tetrafunctional initiated cationic ring-opening polymerization of 2-oxazolines

2021 ◽  
Author(s):  
Francisco Arraez ◽  
Xiaowen Xu ◽  
Mariya Edeleva ◽  
Paul Van Steenberge ◽  
Yoshi Marien ◽  
...  
Keyword(s):  
Mass Distribution ◽  
Ring Opening ◽  
Molar Mass ◽  
Star Polymers ◽  
Ring Opening Polymerization ◽  
Molar Mass Distribution ◽  
Synthesis Technique ◽  
Cationic Ring Opening Polymerization

Cationic ring-opening polymerization (CROP) is an interesting synthesis technique to obtain well-defined polymers with narrow molar mass distribution (MMD). Upon using a multifunctional initiator, well-defined multi-arm or star polymers can...

Structures and potential applications of multihydroxyl branched polyethers obtained by cationic ring-opening polymerization involving activated monomer mechanism

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Melania Bednarek
Keyword(s):  
Ring Opening ◽  
Star Polymers ◽  
Ring Opening Polymerization ◽  
Cyclic Ethers ◽  
Low Molecular Weight ◽  
Hydroxyl Groups ◽  
Potential Applications ◽  
Cationic Ring Opening Polymerization ◽  
Highly Strained ◽  
Thermodynamic Restrictions

AbstractThe synthesis and potential applications of functional, branched polyethers prepared by cationic ring-opening polymerization is reviewed, mainly on the base of the work from the author’s laboratory. Polymerization of cyclic monomers of ABx type, including highly strained 3- and 4-membered as well as weakly strained 5-membered cyclic ethers substituted with hydroxyl groups is discussed. Cationic polymerization of such monomers proceeds with participation of activated monomer mechanism which leads to the formation of branches. Hydroxy-substituted 4-membered cyclic ethers are highly strained; thus there are no thermodynamic restrictions for their polymerization, but these monomers are not easily available. Thus the possibility of using easily accessible 5-membered hydroxy-substituted cyclic ethers as monomers for cationic ring-opening polymerization was explored in spite of expected thermodynamic limitations due to low ring strain of those monomers. It was found that 5-membered hydroxysubstituted cyclic ethers undergo polymerization; however only low molecular weight products may be obtained from these monomers. It is shown in this review that such products may be useful and some examples of their applications in further synthesis e.g. in the preparation of star polymers and as surface modifying agents in the synthesis of organic/inorganic hybrid materials are described.

QELSS diffusion data for moderately broad molar mass distribution polymer samples compared with data from classical gradient techniques

1989 ◽  
Vol 54 (7) ◽  
pp. 1821-1829
Author(s):  
Bedřich Porsch ◽  
Simon King ◽  
Lars-Olof Sundelöf
Keyword(s):  
Diffusion Coefficient ◽  
Mass Distribution ◽  
Molar Mass ◽  
Molar Mass Distribution ◽  
Diffusion Data ◽  
Mass Distributions ◽  
Classical Diffusion ◽  
Polydisperse Polymer

The differences between the QELSS and classical diffusion coefficient of a polydisperse polymer resulting from distinct definitions of experimentally accessible average values are calculated for two assumed specific forms of molar mass distributions. Predicted deviations are compared with the experiment using NBS 706 standard polystyrene. QELSS Dz of this sample relates within 2-4% to the classical diffusion coefficient, if the Schulz-Zimm molar mass distribution is assumed to be valid. In general, differences between the height-area and QELSS diffusion coefficient of about 20% may be found for Mw/Mn ~ 2, and this value may increase above 35%, if strongly tailing molar mass distribution pertains to the sample.

Formation of polyoxazoline-silica nanoparticles via the surface-initiated cationic polymerization of 2-methyl-2-oxazoline

2016 ◽  
Vol 7 (32) ◽  
pp. 5157-5168 ◽  
Author(s):  
G. Bissadi ◽  
R. Weberskirch
Keyword(s):  
Silica Nanoparticles ◽  
Cationic Polymerization ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Hybrid Nanoparticles ◽  
Cationic Ring Opening Polymerization ◽  
Silica Hybrid

The fabrication of silica hybrid nanoparticles by a surface-initiated cationic ring-opening polymerization of poly(2-methyl-2-oxazoline)s has been described.

Evaluation of post-consumer cellulosic textile waste for chemical recycling based on cellulose degree of polymerization and molar mass distribution

2019 ◽  
Vol 89 (23-24) ◽  
pp. 5067-5075 ◽  
Author(s):  
Helena Wedin ◽  
Marta Lopes ◽  
Herbert Sixta ◽  
Michael Hummel
Keyword(s):  
End Of Life ◽  
Intrinsic Viscosity ◽  
Mass Distribution ◽  
Service Sector ◽  
Molar Mass ◽  
Degree Of Polymerization ◽  
Molar Mass Distribution ◽  
Chemical Recycling ◽  
Cellulose Content ◽  
Cellulosic Textiles

The aim of this study is to improve the understanding of which end-of-life cellulosic textiles can be used for chemical recycling according to their composition, wear life and laundering—domestic versus service sector. For that purpose, end-of-life textiles were generated through laboratorial laundering of virgin fabrics under domestic and industrial conditions, and the cellulose content and its intrinsic viscosity and molar mass distribution were measured in all samples after two, 10, 20, and 50 laundering cycles. Results presented herein also address the knowledge gap concerning polymer properties of end-of-life man-made cellulosic fabrics—viscose and Lyocell. The results show that post-consumer textiles from the home consumer sector, using domestic laundering, can be assumed to have a similar, or only slightly lower, degree of polymerization than the virgin textiles (−15%). Post-consumer textiles from the service sector, using industrial laundering, can be assumed to have a substantially lower degree of polymerization. An approximate decrease of up to 80% of the original degree of polymerization can be expected when they are worn out. A higher relative decrease for cotton than man-made cellulosic textiles is expected. Furthermore, in these laboratorial laundering trials, no evidence evolved that the cellulose content in blended polyester fabrics would be significantly affected by domestic or industrial laundering. With respect to molar mass distribution, domestic post-consumer cotton waste seems to be the most suitable feedstock for chemical textile recycling using Lyocell-type processes, although a pre-treatment step might be required to remove contaminants and lower the intrinsic viscosity to 400–500 ml/g.

Accelerated living cationic ring-opening polymerization of a methyl ester functionalized 2-oxazoline monomer

2015 ◽  
Vol 6 (4) ◽  
pp. 514-518 ◽  
Author(s):  
Petra J. M. Bouten ◽  
Dietmar Hertsen ◽  
Maarten Vergaelen ◽  
Bryn D. Monnery ◽  
Marcel A. Boerman ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Ring Opening ◽  
Kinetic Studies ◽  
Ring Opening Polymerization ◽  
Cationic Ring Opening Polymerization

Kinetic studies on the homo- and copolymerization of 2-methoxycarboxyethyl-2-oxazoline with 2-methyl-2-oxazoline and 2-ethyl-2-oxazoline is discussed.

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