scholarly journals Lignin-Based Polyols with Controlled Microstructure by Cationic Ring Opening Polymerization

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 651
Author(s):  
Jonatan Perez-Arce ◽  
Ander Centeno-Pedrazo ◽  
Jalel Labidi ◽  
Jose R. Ochoa-Gomez ◽  
Eduardo J. Garcia-Suarez
Keyword(s):  
Ring Opening ◽  
Average Molecular Weight ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Hydroxyl Groups ◽  
Hydroxyl Number ◽  
Specific Flow ◽  
Melting Temperatures ◽  
Organosolv Lignin ◽  
Cationic Ring Opening Polymerization

Lignin-based polyols (LBPs) with controlled microstructure were obtained by cationic ring opening polymerization (CROP) of oxiranes in an organosolv lignin (OL) tetrahydrofuran (THF) solution. The control on the microstructure and consequently on the properties of the LBPs such as hydroxyl number, average molecular weight, melting, crystallization and decomposition temperatures, are crucial to determine the performance and application of the derived-products. The influence of key parameters, for example, molar ratio between the oxirane and the hydroxyl groups content in OLO, initial OL concentration in THF, temperature, specific flow rate and oxirane nature has been investigated. LBPs with hydroxyl numbers from 35 to 217 mg KOH/g, apparent average Mw between 5517 and 52,900 g/mol and melting temperatures from −8.4 to 18.4 °C were obtained. The CROP procedure allows obtaining of tailor-made LBPs for specific applications in a very simple way, opening the way to introduce LBPs as a solid alternative to substitute currently used fossil-based polyols.

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.

Synthesis of Rare Earth Catalyst LLa[N(TMS)2]•DME(L=3,5-But2-2-HO-C6H2CH-NH-C5H4N) and Catalytic Behavior for Polymerization of Rac-Lactide

2012 ◽  
Vol 184-185 ◽  
pp. 1302-1306
Author(s):  
Xi Zhu ◽  
Yao Rong Wang
Keyword(s):  
Rare Earth ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Elimination Reaction ◽  
Catalytic Behavior ◽  
Rare Earth Catalyst

A dianionic phenoxyamido ligand was the first to be used to stabilize organo-rare-earth mental amido complex. Amine elimination reaction of La[N(SiMe3)2]3(THF)2 with 3,5-But2-2-HO-C6H2CH-NH-C5H4N in a 1 : 1 molar-ratio gave the anionic phenoxyamido neodymium amide LLa[N(TMS)2]•DME (1) in a high isolated yield. Furthemore, the catalytic behavior of complex 1 for the ring-opening polymerization of rac-lactide was explored.

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.

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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