Anionic ring‐opening polymerization of a five‐membered cyclic urethane derived from d‐glucosamine

The anionic ring‐opening polymerization of a five‐membered cyclic urethane, 2‐amino‐4,6‐O‐benzylidene‐2‐N,3‐O‐carbonyl‐2‐deoxy‐α,d ‐glucopyranoside (MBUG), which was prepared from naturally abundant d ‐glucosamine, was examined. Potassium tert‐butoxide (t‐BuOK) was the most effective initiator among the evaluated bases and produced polyurethane with the Mn of 7800 without any elimination of CO₂. The equimolar reaction of MBUG and t‐BuOK in the presence of CH₃I produced N‐methylated MBUG and suggested that the initiation reaction involves proton abstraction from the NH group. This N‐methylated compound did not undergo the polymerization. Therefore, the mechanism of propagation in the ROP of MBUG should involve the proton abstraction and nucleophilic substitution of the resulting amide anion. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2491–2497     

Living cationic ring‐opening polymerization of five‐membered cyclic dithiocarbonate controlled by neighboring group participation of carbamate group

A five‐membered cyclic dithiocarbonate having phenylcarbamate moiety 1 underwent cationic ring‐opening polymerization by using methyl trifluoromethanesulfonate as an initiator in nitrobenzene at 60 °C. Both of the corresponding first‐order kinetic plot and conversion‐molecular weight plot showed linearity to suggest the living fashion of the polymerization, which was then supported by two‐stage polymerization experiment. The living fashion as well as the regioselective formation of the repeating unit suggested significant contribution of the neighboring group participation of the carbamate group to form a stabilized cationic propagating end, of which structure was confirmed by performing an equimolar reaction of 1 and methyl trifluoromethanesulfonate with analyzing the resulting species by NMR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4459–4464, 2007     

Cationic ring‐opening polymerization behavior of a five‐membered cyclic thiocarbonate having a spiro‐linked adamantane moiety

This work deals with the synthesis and cationic ring‐opening polymerization behavior of a novel five‐membered cyclic thiocarbonate bearing a spiro‐linked adamantane moiety, tricyclo[3.3.1.1^3,7]decane‐2‐spiro‐4′‐(1′,3′‐dioxolane‐2′‐thione) ( TC2 ). The cationic ring‐opening polymerization of TC2 did not proceed with trifluoromethanesulfonic acid, methyl trifluoromethanesulfonate, triethyloxonium tetrafluoroborate (Et₃OBF₄), boron trifluoride etherate (BF₃OEt₂), titanium tetrachloride, or methyl iodide as the initiator, presumably because of the steric hindrance of the adamantane moiety. However, the cationic ring‐opening copolymerization of TC2 with five‐ or six‐membered cyclic thiocarbonates, that is, 1,3‐dioxolane‐2‐thione, 1,3‐dioxane‐2‐thione, 5‐methyl‐1,3‐dioxane‐2‐thione, or 5,5‐dimethyl‐1,3‐dioxane‐2‐thione, initiated by BF₃OEt₂ or Et₃OBF₄, proceeded to afford the corresponding copolymer via a selective ring‐opening direction. The increase in the feed ratio of TC2 in the copolymerization increased the unit ratio derived from TC2 in the copolymer; however, the molecular weight of the copolymer decreased. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 699–707, 2003     

Cationic ring‐opening polymerization of six‐membered cyclic carbonates with ester groups

This work deals with the cationic ring‐opening polymerization of the ester‐substituted cyclic carbonates 5‐methyl‐5‐benzoyloxymethyl‐1,3‐dioxan‐2‐one ( CC1 ) and 4‐benzoyloxymethyl‐1,3‐dioxan‐2‐one ( CC4 ). The polymerization was carried out with trifluoromethanesulfonic acid, methyl trifluoromethanesulfonate, boron trifluoride etherate, or methyl iodide as the initiator. The reactivity of CC1 and CC4 was higher than that of 5,5‐dimethyl‐1,3‐dioxan‐2‐one, which had no ester moiety. These results suggest that this ring‐opening polymerization was accelerated by the intramolecular ester group. CC1 showed a higher polymerizability than CC4 , affording a polymer with a higher molecular weight. Additionally, using methyl iodide as the initiator was effective for increasing the molecular weight of the obtained polycarbonate and decreasing decarboxylation. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1305–1317, 2001     

Synthesis and cationic ring‐opening polymerization of oxetane monomer containing five‐membered cyclic carbonate moiety via highly chemoselective addition of CO2

The bicyclic amidinium iodide effectively catalyzed the reaction of carbon dioxide and the epoxy‐containing oxetane under ordinary pressure and mild conditions with high chemoselectivity to give the corresponding oxetane monomer containing five‐membered cyclic carbonate quantitatively. The cationic ring‐opening polymerization of the obtained monomer by boron trifluoride diethyl ether proceeded to give linear polyoxetane bearing five‐membered cyclic carbonate pendant group in high yield. The molecular weight of the polyoxetane was higher than that of polyepoxide obtained by the cationic ring‐opening polymerization of epoxide monomer containing five‐membered cyclic carbonate. The cyclic carbonate functional crosslinked polyoxetanes were also synthesized by the cationic ring‐opening copolymerization of cyclic carbonate having oxetane and commercially available bisoxetane monomers. Analyses of the resulting polyoxetanes were performed by proton nuclear magnetic resonance, size exclusion chromatography, thermogravimetric analysis, and differential scanning calorimetry. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2606–2615     

Radical ring‐opening polymerization of five‐membered cyclic vinyl sulfone using p‐toluenesulfonyl halides

Radical ring‐opening polymerizations of a five‐membered cyclic vinyl sulfone monomer, 2‐vinylthiolane‐1,1‐dioxide (VTDO), was carried out by using p‐toluenesulfonyl iodide (TosI) and bromide (TosBr) as radical initiators, and the corresponding ring‐opened polymer (PVTDO) was obtained. Both TosI and TosBr were found to work as the radical initiators for the polymerization of VTDO in bulk. The use of TosI gave PVTDOs with a broad, multimodal distribution of molecular weight in low yields. When 10 mol % of TosBr was employed, the isolated yield of PVTDO reached 49%, and the obtained PVTDO had a relatively narrow, monomodal molecular weight distribution of 1.8 with an M_n of 4100. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Radical ring‐opening polymerization

The radical ring‐opening polymerization (RROP) behavior of the following monomers is reviewed, and the possibility for application to functional materials is described: cyclic disulfide, bicyclobutane, vinylcyclopropane, vinylcyclobutane, vinyloxirane, vinylthiirane, 4‐methylene‐1,3‐dioxolane, cyclic ketene acetal, cyclic arylsulfide, cyclic α‐oxyacrylate, benzocyclobutene, o‐xylylene dimer, exo‐methylene‐substituted spiro orthocarbonate, exo‐methylene‐substituted spiro orthoester, and vinylcyclopropanone cyclic acetal. RROP is a promising candidate for producing a wide variety of environmentally friendly functional polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 265–276, 2001     

Synthesis and radical polymerization of styrene‐based monomer having a five‐membered cyclic carbonate structure

A styrene‐based monomer having a five‐membered cyclic carbonate structure, 4‐vinylbenzyl 2,5‐dioxoran‐3‐ylmethyl ether (VBCE), was prepared by lithium bromide‐catalyzed addition of carbon dioxide to 4‐vinylbenxyl glycidyl ether (VBGE). Radical polymerization of the obtained VBCE was carried out using 2,2′‐azobisisobutyronitrile as an initiator. PolyVBCE with number‐averaged molecular weight higher than 13,800 was obtained by a solution polymerization in N,N‐dimethylformamide, N,N‐dimethylacetamide, dimethyl sulfoxide, and methyl ethyl ketone. The glass transition temperature and 5 wt % decomposition temperature of the polyVBCE were determined to be 52 and 305 °C by differential scanning calorimetry and thermal gravimetry analysis, respectively. It was confirmed that a polymer consisting of the same VBCE repeating unit can be also obtained via chemical modification of polyVBGE, that is, a lithium‐bromide‐catalyzed addition of carbon dioxide to a polyVBGE prepared from a radical polymerization of VBGE. Further copolymerization of VBCE with styrene gave the corresponding copolymer in a high yield. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Substituent effect on the cationic ring‐opening polymerization of acyloxymethyl five‐member cyclic dithiocarbonates

Five‐member cyclic dithiocarbonates were synthesized by the reactions of carbon disulfide with benzoic, p‐anisic, p‐chlorobenzoic, 1‐naphthalenecarboxylic, p‐nitrobenzoic, and p‐(tert‐butyl)benzoic glycidyl esters, and their cationic ring‐opening polymerizations were carried out with methyl trifluoromethane sulfonate and trifluoromethane sulfonic acid as initiators at room temperature to 80 °C. Polymers with number‐average molecular weights of 3400–24,900 were obtained in high yields, and their structures were estimated by NMR and IR spectroscopy. The monomers showed a clear difference in the polymerization rate according to the substituents. The rate of polymerization decreased in the order of p‐chlorobenzoic ≥ benzoic > 1‐naphthalenecarboxylic > p‐nitro‐benzoic > p‐tert‐butylbenzoic > p‐anisic. The data of the reaction kinetics, NMR studies, and molecular orbital calculations proved a plausible mechanism involving the participation of p‐substituted benzoyloxymethyl groups to stabilize the cationic propagating end. The polymers showed decomposition temperatures with 5% weight loss ranging from 200 to 260 °C. No glass‐transition temperatures for the polymers were observed below 200 °C by differential scanning calorimetry. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3967–3980, 2001     

Microwave‐assisted ring‐opening polymerization of trimethylene carbonate in the presence of ionic liquid

Microwave‐assisted ring‐opening polymerization (MROP) of trimethylene carbonate in the presence of 1‐n‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim]BF₄) ionic liquid was investigated. In the presence of 5 wt % [bmim]BF₄, poly (trimethylene carbonate) (PTMC) with a number‐average molar mass (M_n) of 36,400 g/mol was obtained at 5 W for only 60 min. The M_n of PTMC synthesized in the presence of [bmim]BF₄ was much higher than that produced in bulk at the same reaction time. In addition, compared with those produced by conventional heating, the M_n of PTMC and monomer conversion by MROP with or without [bmim]BF₄ were both higher. Thermal properties of the resulting PTMC were characterized by differential scanning calorimetry. Under microwave irradiation in the presence of ionic liquid, the polymerization could be carried out efficiently and effectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5857–5863, 2007     

Addition of five‐membered cyclic carbonate with amine and its application to polymer synthesis

A bifunctional five‐membered cyclic carbonate was synthesized from carbon dioxide and diglycidyl terephthalate, and its polyaddition with alkyl diamines were carried out in DMF at room temperature to obtain the corresponding poly(hydroxyurethane)s with M_n s in the range of 6300–13200 in good yields. The structures of the obtained polymers were confirmed by IR and NMR spectroscopy and their glass‐transition and decomposition temperatures were observed at 3–29 °C and 182–277 °C, respectively. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2375–2380, 2000     

Synthesis,characterization, and mechanism studies on novel rare‐earth calixarene complexes initiating ring‐opening polymerization of 2,2‐dimethyltrimethylene carbonate

Rare‐earth (Nd, Y) p‐tert‐butylcalix[n]arene (n = 4, 6, and 8) complexes without coligands were synthesized from rare‐earth isopropoxides in toluene. The products were characterized as the following structures: [C4(OH)O₃ · CH₃C₆H₅]Nd ( 4 ), [C6(OH)₂O₄ · CH₃C₆H₅]₃Ln₄ [Ln = Nd ( 5 ), Y ( 6 )], and [C8(OH)₂O₆ · CH₃C₆H₅]Nd₂ ( 7 ). 2,2‐Dimethyl trimethylene carbonate (DTC) can be polymerized with complexes 4 – 7 alone as the initiator. PolyDTC (weight‐average molecular weight: 5700, polydispersity index: 1.11, measured by gel permeation chromatography) initiated by complex 5 was obtained with a conversion of 69.1% within 6 h in toluene at 80 °C. The thermal behavior of polyDTC has been compared with the published data. The DTC ring is opened via acyl‐oxygen bond cleavage with end‐group examination. NMR analyses of the polymerization reaction mixture indicated that the polymerization proceeds via a coordination‐insertion mechanism. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1390–1399, 2003     

Anionic ring‐opening polymerization of N‐glycidylphthalimide: Combination of phosphazene base and activated monomer mechanism

Anionic ring‐opening polymerization of glycidyl phthalimide, initiated with alcohol–phosphazene base systems and based on monomer activation with a Lewis acid (iBu₃Al), has been studied. No propagation occurred for initiator: iBu₃Al ratios less or equal to 1:3. For larger Lewis acid amounts, the first anionic ring‐opening polymerizations of glycidyl phthalimide were observed. Polymers were carefully characterized by NMR, MALDI‐TOF mass spectrometry, and size exclusion chromatography and particular attention was given to the detection of eventual transfer or side‐reactions. However, polymer precipitation and transfer reaction to aluminum derivative were detrimental to monomer conversion, polymerization control, and limited polymer chain molar masses. The influence of reaction temperature and solvent on polymer precipitation and transfer reactions was studied and reaction conditions have been optimized leading to afford end‐capped poly(glycidyl phthalimide) with narrow molar mass distributions. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1091–1099     

Facile synthesis and crosslinking reaction of trifunctional five‐membered cyclic carbonate and dithiocarbonate

The trifunctional five‐membered cyclic carbonate 2 and dithiocarbonate 3 were successfully synthesized by the reaction of trifunctional epoxide 1 with carbon dioxide and carbon disulfide, respectively. The crosslinking reactions of 2 with p‐xylylenediamine or hexamethylenediamine were carried out in dimethyl sulfoxide at 100 °C for 48 h to produce the corresponding crosslinked poly(hydroxyurethane)s quantitatively. The crosslinking reactions of 3 with both p‐xylylenediamine and hexamethylenediamine, followed by acetylation of thiol moiety, produced the corresponding crosslinked poly(thioester–thiourethane)s quantitatively. The obtained crosslinked poly(hydroxyurethane)s were thermally more stable than the analogous crosslinked poly(thioester–thiourethane)s, probably because of less thermal stability of thiourethane moiety than hydroxyurethane moiety. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5983–5989, 2004     

Cationic ring‐opening polymerization of monothiocarbonate with a norbornene group

This work deals with the cationic ring‐opening polymerization of cyclic thiocarbonates with a norbornene or norbornane moiety, that is, 5,5‐(bicyclo[2.2.1]hept‐2‐ene‐5,5‐ylidene)‐1,3‐dioxane‐2‐thione ( TC1 ) or 5,5‐(bicyclo[2.2.1]heptane‐5,5‐ylidene)‐1,3‐dioxane‐2‐thione ( TC2 ), respectively. The reaction of TC1 initiated by trifluoromethanesulfonic acid (TfOH), methyl trifluoromethanesulfonate (TfOMe), boron trifluoride etherate (BF₃OEt₂), or triethyloxonium tetrafluoroborate (Et₃OBF₄) afforded unidentified products; however, TC1 underwent cationic ring‐opening polymerization with methyl iodide as an initiator to afford polythiocarbonate because the propagating end was stabilized by the covalent‐bonding property. The polymerization of TC2 initiated by TfOH, TfOMe, BF₃OEt₂, or Et₃OBF₄ afforded polythiocarbonate with good solubility in common organic solvents and a narrow molecular weight distribution because of the absence of a double‐bond moiety. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1698–1705, 2002     

Ring‐opening polymerization of six‐membered cyclic carbonates initiated by ethanol amine derivatives and their application to protonated or quaternary ammonium salt‐functionalized polycarbonate films

Ring‐opening polymerization (ROP) of monofunctional neopentylglycol carbonate (NPGC) with or without bifunctional di(trimethylolpropane) carbonate (DTMPC), which are derived from available corresponding alcohols, affords linear polycarbonates or covalently‐linked polycarbonate networks, respectively. A series of available ethanol amine derivatives having the different numbers of 2‐hydroxylethyl arms (N,N,N’,N’‐tetrakis(2‐hydroxyethyl)ethylenediamine, triethanolamine, N‐methyldiethanolamine or N,N‐dimethylethanolamine) initiates the ROP of NPGC to afford star‐shaped, telechelic, or linear polycarbonates bearing tertiary amines with well‐controlled molecular weights and relatively narrow polydispersities Furthermore, the copolymerization of NPGC and DTMPC in the presence of these initiators readily gives tertiary amine‐modified polycarbonate films with well transparency and flexibility. These amino groups are easily converted to ammonium salts by protonation with acids, while the quaternization with benzyl bromide is strongly affected by the steric hindrance of these amines. N‐Methyldiethanolamine or N,N‐dimethylethanolamine residues in these films react easily with benzyl bromide to give quaternary ammonium salt‐functionalized films. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 487–497     

Modification of proline‐based 2,5‐diketopiperazines by anionic ring‐opening polymerization

2,5‐Diketopiperazines (DKPs) are the smallest cyclic dipeptides found in nature with various attractive properties. In this study, we have demonstrated the successful modification of proline‐based DKPs using anionic ring‐opening polymerization (AROP) as a direct approach. Four different proline‐based DKPs with various side chains and increasing steric hindrance were used as initiating species for the polymerization of 1,2‐epoxybutane or ethoxyethyl glycidyl ether in the presence of t‐BuP₄ phosphazene base. The addition of a Lewis acid, tri‐isobutyl aluminum, to the reaction mixture strongly decreased the occurrence of side reactions. Impact of the DKP side‐chain functionalities on molar mass control and dispersity was successfully evidenced. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 1008–1016     

Synthesis of refractive star‐shaped polysulfide by anionic polymerization of phenoxy propylene sulfide using an initiating system consisting of trifunctional thiol derived from five‐membered cyclic dithiocarbonate and amine

Star‐shaped poly(phenoxy propylene sulfide) [poly (PPS)] were synthesized by anionic polymerization using a trifunctional initiator ( I ₁) derived from a trifunctional five‐membered cyclic dithiocarbonate and benzyl amine. Conditions for the anionic polymerization of PPS were optimized to obtain polymers with desired M_ns and narrow M_w/M_ns. The best catalyst and solvent were DBU and DMF, respectively. The star‐shaped structure of the resulting star poly(PPS) was supported by SEC analysis. The refractive indexes (n_D) of the star poly (PPS) were relatively high (>1.64). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 525–531, 2010     

Less toxic acetylacetonates as initiators of trimethylene carbonate and 2,2‐dimethyltrimethylene carbonate ring opening polymerization

This article presents the results of TMC and DMC polymerization with the use of acetylacetonates of low‐toxic metals: iron, zinc, and zirconium. Zinc (II) acetylacetonate proves to be a very good initiator of homopolymerization. The reaction carried out with the use of this initiator at 110 °C is very rapid and of high yield. Using both zinc and iron (III) acetylacetonates, as well as the zirconium (IV) one, in high temperatures it is possible to obtain PTMC possessing high molecular mass, thus ensuring optimization of the relation between the duration of the polymerization and its yield. A strong influence of thermal degradation on the course of the reaction has been observed, particularly at 160 °C, with the use of Fe(acac)₃ as the initiator. DMC polymerization proceeds much more slowly when initiated by iron and zinc acetylacetonates. A high conversion of the monomer is obtained in this case as well. The relation between the molecular mass of the obtained PDMC and the conversion of the monomer is directly proportional; however, those masses, determined on the basis of polystyrene standards, are much lower than those estimated theoretically. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1913–1922, 2005     

Synthesis of polycarbosilanes having a five‐membered cyclic carbonate structure and their application to prepare gel polymer electrolytes for lithium ion batteries

A silacyclobutane having a five‐membered cyclic carbonate structure (SBMC) was prepared, and its transition metal‐catalyzed ring‐opening polymerization at the four‐membered carbosilane unit was investigated as well as formation of carbosilane networked polymers and polymer gel electrolytes. The SBMC was synthesized by epoxidation of 1‐(4‐butenyl)‐1‐methylsilacyclobutane followed by insertion of CO₂ to the epoxide. Ring‐opening polymerization of the silacyclobutane moiety in the SBMC readily proceeded by a transition metal catalyst such as platinum divinyltetramethyldisiloxane complex. A flexible networked polymer film was obtained by copolymerization of the SBMC with a small amount of crosslinker, hexamethylene‐1,6‐bis(1‐methylsilacyclobutane) (HMBS). The copolymerization of SBMC and HMBS in 1 M LiPF₆ solution in ethylene carbonate and diethyl carbonate (3/7 v/v) gave a gel polymer electrolyte, which showed good ionic conductivity and could be applied to lithium ion batteries. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012