The influence of macrocyclic ligands and water on propylene oxide polymerization initiated with anhydrous potassium hydroxide in tetrahydrofuran

Grobelny, Zbigniew; Matlengiewicz, Marek; Jurek, Justyna; Michalak, M.; Kwapulińska, Danuta; Swinarew, Andrzej; Schab‐Balcerzak, Ewa

doi:10.1016/j.eurpolymj.2013.06.035

Cited by 12 publications

(33 citation statements)

References 23 publications

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“…2, the predominating signals of the starting group formed during b-opening (carbons 1, 2 and 3) may be found at 9.73, 29.07, and 19.14 ppm, respectively, while those from a-opening (carbons 4, 5 and 6) at 9.88, 32.04, and 22.10, respectively. Splitting of all the mentioned signals into two lines may be due to the presence of asymmetric methine carbon in these groups as it was already observed in our earlier work on PPO [18]. initiation exclusively in the b-position (Fig.…”

Section: Resultssupporting

confidence: 65%

Ring opening polymerization of styrene oxide initiated with potassium alkoxides and hydroxyalkoxides activated by 18-crown-6: determination of mechanism and preparation of new polyether-polyols

et al. 2017

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It was stated that initiation in ring opening polymerization of styrene oxide depends on the kind of potassium alkoxide activated by 18-crown-6 used. In the presence of potassium methoxide the oxirane ring opening occurs exclusively in the b-position and not in the b or a position, i.e., contrary to the previous data. A similar result was obtained in the systems initiated with potassium t-butoxide, 2-methylpropoxide and 1-phenylethoxide. Unexpectedly, potassium i-propoxide and 1-methylpropoxide open the oxirane ring in the b or a position. In all polymerizations, deprotonation of methine group in the monomer takes place under the influence of the initiator and in chain transfer reaction to the monomer. It leads to the formation of macromolecules with unsaturated starting group. However, deprotonation of methylene group in the monomer does not occur. Applying of potassium hydroxyalkoxides, i.e., monopotassium salt of dipropylene glycol or tripotassium salt of 2,2,6,6-tetrakis(hydroxymethyl)cyclohexanol it was possible to synthesize PSO-diols and PSO-pentols without unsaturation. Molar masses of polymers (M n = 1700-4800 Da) are much higher than reported in literature for other anionic systems. Dispersity of polymers is rather low (M w /M n = 1.07-1.15) indicating relatively high rate of initiation and cation exchange reaction.

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Section: Resultssupporting

confidence: 65%

Ring opening polymerization of styrene oxide initiated with potassium alkoxides and hydroxyalkoxides activated by 18-crown-6: determination of mechanism and preparation of new polyether-polyols

et al. 2017

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“…Then, the solvent was evaporated in vacuum. The KH present was determined by a standard gas law calculation of the hydrogen liberated after treating with 2-butanol (1.0 H 2 = 1.0 KH) [23]. The resulting solution was titrated to a phenolphthalein end point.…”

Section: Experimental Part Materialsmentioning

confidence: 99%

“…Moreover, in 2007 Penczek et al [20] reported in review paper concerning ring-opening polymerization of heterocyclic monomers that the side transfer reaction in propylene oxide polymerization can be depressed to the same extent by counterion complexation with crown ethers. However, the results presented in several works [8,10,[21][22][23] revealed that this effect was observed in the systems containing compounds with OH groups. Addition of 18-crown-6 (18C6) to the systems containing alcohol causes further depression of chain transfer to the monomer resulting in distinct decreasing of unsaturation and increasing of M n [8,22].…”

Section: Introductionmentioning

confidence: 99%

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The influence of initiator and macrocyclic ligand on unsaturation and molar mass of poly(propylene oxide)s prepared with various anionic system

et al. 2017

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Anionic polymerization of propylene oxide was carried out in the presence of two groups of potassium salts activated 18-crown-6 (18C6), e.g. alkoxide salts (CH 3 OK, i-PrOK, t-BuOK, CH 3 OCH 2 CH(CH 3 )OK, KCH 2 O) and other salts (CbK, Ph 3 CK, Ph 2 PK, Ph 3 HBK, KK, KH, and [(CH 3 ) 3 Si] 2 NK) in THF at room temperature. Application of various initiating systems results in polyethers which are different in level and kind of unsaturation represented by allyloxy, cis-and trans-propenyloxy, as well as vinyloxy starting groups. In the presence of selected initiator, i.e. t-BuO -K ? unsaturation increases markedly by addition of 18C6 or C222. During the initiation step oxirane ring-opening and direct deprotonation of the monomer occur simultaneously involving in some cases also the ligand. All initiators opens oxirane ring in the b-position except i-PrOK, which opens it in the b-and a-position. The mechanisms of the reactions were discussed.

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“…However, in the case of polymerization of propylene oxide and styrene oxide, side reactions take place resulting in the formation of macromolecules with -OH end group (10-15 %) [23,27,28]. However, in the case of methyl methacrylate, another type of side reaction occurs during the initiation, i.e., acyl-oxygen bond cleavage (14 %) resulting in macromolecules with CH 3 Ostarting groups [29,30]. The chemical structure of synthesized polymers was confirmed by 13 C NMR.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

Novel concept of polymers preparation with high photoluminescent quantum yield

et al. 2016

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A series carbazolyl-containing polymers were synthesized by anionic polymerization of various oxiranes and methyl methacrylate. The polymerization was carried out using as initiator carbazylpotassium activated 18-crown-6 in THF. The polymers were prepared and found using size exclusion chromatography to have a degree of polymerization (DP n ) about 20 relatively and low dispersity in the range of 1.07-1.66. Their optical properties were investigated by means of UV-vis and photoluminescence spectroscopies. The obtained polymers emitted light with maximum emission about 370 nm and high quantum yield ranging up to 79 %. Thus, it was confirmed that the utilization of fluorophore initiator for polymerization of non photoresponsive monomers is quite efficient for the preparation of photoluminescent polymers.

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The influence of macrocyclic ligands and water on propylene oxide polymerization initiated with anhydrous potassium hydroxide in tetrahydrofuran

Cited by 12 publications

References 23 publications

Ring opening polymerization of styrene oxide initiated with potassium alkoxides and hydroxyalkoxides activated by 18-crown-6: determination of mechanism and preparation of new polyether-polyols

Ring opening polymerization of styrene oxide initiated with potassium alkoxides and hydroxyalkoxides activated by 18-crown-6: determination of mechanism and preparation of new polyether-polyols

The influence of initiator and macrocyclic ligand on unsaturation and molar mass of poly(propylene oxide)s prepared with various anionic system

Novel concept of polymers preparation with high photoluminescent quantum yield

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