Ring-opening Polymerization Of Tetrahydrofuran Research Articles

End-reactive poly(tetrahydrofuran) for functionalization and graft copolymer synthesis via a conjugate substitution reaction

α-(Chloromethyl)acryloyl cation, prepared from the corresponding acyl chloride and silver triflate, was used as an initiator for the living, cationic ring-opening polymerization of tetrahydrofuran. The α-end of the resulting poly(tetrahydrofuran) has an α-(chloromethyl)acrylate skeleton, which is an excellent substrate for nucleophilic conjugate substitution. In fact, treatment with a phenol resulted in a functionalized α-end. Moreover, 2-aminoethylanol and 2-mercaptoethanol afforded doubly functionalized polymers with two hydroxy groups at the α-ends via conjugate substitution and subsequent addition reactions. Since α-(chloromethyl)acrylate can be attacked by two equivalents of a nucleophile, it can function as a monomer in polycondensations with dithiols. Therefore, the α-(chloromethyl)acrylate chain end was subjected to polycondensation with 1,10-decandithiol in the presence of Bu3P, resulting in a graft copolymer. The above results suggest that the α-(chloromethyl)acryloyl cation is a functional initiator for incorporating a chain end reactive to a variety of nucleophiles for single and double end-functionalizations and the preparation of graft copolymers. Conjugate subst. allows single/double end-functionalization and graft copolymer synthesis.

Synthesis of fluorescent diblock copolymer nanoparticle supported catalyst for the reduction of Cr(VI), p-nitrophenol and rhodamine 6G dye: a comparative study

A fluorescent diblock copolymer nanocomposite (DBCNC) was synthesized by ring opening polymerization (ROP) method using rhodamine 6G (R6G) dye as an initiator through bulk polymerization technique. ROP of caprolactone was carried out at $$160^{\circ } \hbox {C}$$ for 2 h under nitrogen atmosphere in the presence of stannous octoate (Sn(Oct) $$_{2}$$ ) as a catalyst followed by the ROP of tetrahydrofuran in the presence of phthalicanhydride as a co-monomer. Thus, synthesized fluorescent DBCNC was characterized by various analytical tools such as FTIR spectroscopy, UV–visible spectroscopy fluorescence emission spectroscopy, DSC, TGA and FESEM. The catalytic reduction of p-nitrophenol (NiP), Cr(VI) and R6G was carried out in the presence of DBCNC as a catalyst with the help of UV–visible spectrophotometer. The apparent rate constant ( $$k_{\mathrm{app}}$$ ) and induction time ( $$T_{\mathrm{i}}$$ ) were determined from the UV–visible spectral data. The nanosized $$\hbox {V}_{2} \hbox {O}_{5}$$ was prepared by a simple chemical reduction of bulk-sized $$\hbox {V}_{2}\hbox {O}_{5}$$ by using sodium borohydride ( $$\hbox {NaBH}_{4}$$ ) as a reducing agent. During the DBC formation, 0.01 g of nanosized $$\hbox {V}_{2}\hbox {O}_{5}$$ was added. This type of polymer supports the catalyst which is very much useful in the catalysis industry because of its easy separation and recyclable property.

A Simple and Reusable Polyaniline Catalyst for the Ring-opening Polymerization of Tetrahydrofuran

A Simple and Reusable Polyaniline Catalyst for the Ring-opening Polymerization of Tetrahydrofuran

Synthesis, characterization, catalytic and splinting activity of nano Ag end capped l‐glutathione bridged amphiphilic diblock copolymer

ABSTRACTl‐glutathione, a naturally occurring environmental friendly amino acid, was used as an initiator towards the ring opening polymerization (ROP) of ɛ‐caprolactone (CL) followed by the ROP of tetrahydrofuran (THF). The thiol group of l‐glutathione reduces Ag+ ions and chemically bound to the surface of Ag nanoparticles. The ROP of CL was carried out at 160 °C under nitrogen atmosphere in the presence of stannous octoate(SO) as catalyst whereas the ROP of THF was carried out at 45 °C for 24 h in the presence of phthalic anhydride (PAH) as a comonomer. The synthesized homo, di and nano Ag end capped diblock copolymers were characterized by FTIR, DSC, TGA, FESEM, high resolution transmission electron microscope (HRTEM), EDAX, GPC, nuclear magnetic resonance (NMR), Fluorescence and CD. Further the application of diblock copolymer was tested for splinting activity. The catalytic reduction of 4‐nitrophenol (NP) in the presence of nano Ag end capped diblock copolymer was carried out with the assistance of sodium borohydride as a reducing agent and the apparent rate constant (kapp) was determined and compared with the literature values. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43804.

Synthesis and characterization of novel fluorescent amphiphilic diblock copolymer

In the present study, an amphiphilic diblock copolymer made of poly(e-caprolactone) (PCL) and poly(tetrahydrofuran) (PTHF) was synthesized via ring opening polymerization (ROP) of e-caprolactone (CL) and tetrahydrofuran (THF) with rose bengal (RB) as a bridging agent in a two-step process. In the first step, RB–PCL was synthesized by the ROP of CL, while in the second step the diblock copolymer was prepared by the ROP of THF with RB–PCL moiety as a chemical initiator in the presence of phthalic anhydride (PAH) as a co-monomer. The diblock copolymer was characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infra red (FTIR) spectroscopy, UV–visible spectroscopy, fluorescence spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), gel permeation chromatography (GPC) and EDX studies.

Synthesis, Characterization, Drug Delivery, and Splinting Activity of Folic Acid Bridged Poly(ɛ-caprolactone-co-tetrahydrofuran)

Synthesis of a material for drug delivery application is a fascinating field of research. Folic acid (FA) is an anticancer drug and is used as an initiator for the ring opening polymerization of ϵ-caprolactone (CL) at 160°C for 2 h under N2 atmosphere. The FA end-capped PCL (P1) was used as an effective initiator for the ring opening polymerization of tetrahydrofuran (THF) in the presence of phthalic anhydride (PAH) as a comonomer (P2) at 45°C for 48 h under inert atmospheric condition with mild stirring. The obtained polymers were characterized by FTIR, NMR, DSC, TGA, FESEM, GPC, SEM, UV-visible spectrometry, and EDAX. Appearance of a peak at 1595 cm−1 confirmed the formation of copolymer through tetrahydrofuronium ion. The copolymer structure can be confirmed by noting a peak at 7.6 ppm in the 1H-NMR spectrum. The increase in weight average molecular weight of P2 confirmed the copolymer formation. The previously synthesized polymer was tested toward the splitting application and further confirmed by determining the tensile strength. The drug delivery study was also conducted. P1 and P2 exhibited the Hixson-Crowell and Higuchi model drug release mechanisms, respectively. The water contact angle measurement also confirmed the conversion of hydrophobic in to hydrophilic during the copolymer formation.

Synthesis of (adamantylimido)vanadium(V)-alkyl complexes containing aryloxo ligands and their use as the catalyst precursors for ring-opening metathesis polymerization of norbornene, and ring-opening polymerization of tetrahydrofuran

Various (adamantylimido)vanadium(V) dialkyl complexes containing aryloxo ligands, V(NAd)(CH 2SiMe 3) 2(OAr) [Ad = 1-adamantyl ( 1); Ar = Ph ( a), 4-FC 6H 4 ( b), 2,6-F 2C 6H 3 ( c), 2,6-Me 2C 6H 3 ( d), C 6F 5 ( e)], have been prepared and identified. These complexes were employed as the catalyst precursors for ring-opening metathesis polymerization (ROMP) of norbornene (NBE) in the presence of PMe 3 at 80 °C. The activity was strongly affected by the aryloxo substituent and increased in the order: C 6H 5 < 4-FC 6H 4 < 2,6-Me 2C 6H 3 << 2,6-F 2C 6H 3, C 6F 5. The same trend was observed in the ROMPs by the arylimido–aryloxo analogues, V(NAr′)(CH 2SiMe 3) 2(OAr) ( 2a– e; Ar′ = 2,6-Me 2C 6H 3), under the same conditions, and the activities by the arylimido analogues were generally higher than the adamantylimido analogues in most case. The (imido)vanadium(V) complexes containing O-2,6-F 2C 6H 3 ( 1, 2c) or OC 6F 5 ( 1, 2e) exhibited high catalytic activities, and these results strongly suggest that electronic as well as steric factors play a role. Living ring-opening polymerization of THF proceeded in the presence of V(NAd) (CH 2SiMe 3)(OAr) 2 (Ar = 2,6-Me 2C 6H 3, C 6F 5) and [Ph 3C][B(C 6F 5) 4], affording high molecular weight polymers with narrow molecular weight distributions (ex. M n = 2.11 × 10 5, M w / M n = 1.18).

Micelle Behavior of Copolymers Composed of Linear and Hyperbranched Blocks in Aqueous Solution

AbstractMulti‐arm poly(THF)‐b‐polyglycerol linear‐hyperbranched copolymers consisting of a linear hydrophobic poly(THF) block and a hyperbranched hydrophilic polyglycerol block were synthesized by ring opening polymerization of tetrahydrofuran with silver trifluoromethane sulfonate as a catalyst and the consecutive polymerization of glycidol. Initiators with different geometries that propagated into different numbers of arms (e.g., 1, 2 or 4) were used to investigate the dependence of the micelle properties of the copolymers on the number of arms. The critical micelle concentration (CMC) first decreased and then increased with increasing numbers of arms showing a minimum CMC at an arm number of 2. A minimum CMC was difficult to obtain using multi‐arm block copolymers composed of linear polymers with the small number of arms investigated in this study. DLS showed that the 4‐arm poly(THF)‐b‐polyglycerol copolymer had a micelle size of approximately 83 nm under aqueous conditions, and the micelle size of the copolymers with different numbers of arms was similar. Unimolecular micelles could eventually be obtained using this system by increasing the number of arms, they are considered an ideal drug delivery carrier due to the concentration‐independent stability in the blood stream.magnified image

Block and Star-Block Copolymers by Mechanism Transformation. 3. S-(PTHF-PSt)4and S-(PTHF-PSt-PMMA)4from Living CROP to ATRP

Star-shaped poly(tetrahydrofuran) tetrols were prepared by living cationic ring-opening polymerization of tetrahydrofuran and esterified with bromoacetyl and bromoisobutyryl chloride. The intermediate produced was used as macroinitiator to initiate the atom transfer radical polymerization (ATRP) of styrene and subsequently atom transfer radical polymerization of methyl methacrylate at 80−110 °C with CuBr/2,2‘-bipyridine as catalyst. Kinetic studies and GPC analyses provided the evidences of “living” polymerization: constant concentration of active species, narrow molecular weight distribution, and well control of molecular weight. The NMR spectra and GPC analyses demonstrated the formations of four-armed star polymer and copolymers: S-(PTHF)4, S-(PTHF-PSt)4, and S-(PTHF-PSt-PMMA)4. For S-(PTHF-PSt)4, this conclusion was further confirmed by GPC analysis of the PSt obtained from hydrolysis of the copolymer.

Preparation of polytetrahydrofuran monomethacrylate macromonomers by cationic ring-opening polymerization of tetrahydrofuran

Polytetrahydrofuran monomethacrylate (MA-PTHF) macromonomer was prepared by cationic ring-opening polymerization(CROP) of tetrahydrofuran (THF) using boron trifloride etherate (BF3 · OEt2) as initiator and epichlorohydrin (ECH) as promoter. Two kinds of transfer agents were used: methacrylic acid (represented as TA1), and a mixture of methacrylic acid and sodium methacrylate (represented as TA2). The effects of polymerization conditions on molecular weight and molecular weight distribution of macromonomers were studied in this article, when the composition of reactants was kept constant. Under the same conditions, the molecular weight of macromonomer using TA2 is lower than that using TA1, which indicates that TA2 is more active than TA1. The molecular weight of MA-PTHF macromonomer varies with the polymerization time before transfer agents were added (T1), but molecular weight distribution remains constant. When T1 is limited in 30 min, the apparent number-average molecular weight of MA-PTHF increases significantly with the increase of T1, and ranges from 5000 to 18,000. Hence, the molecular weight of MA-PTHF macromonomer can be controlled by varying T1. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 810–815, 2000

Block copolyurethanes containing poly(12-hydroxy stearate) and poly(oxy tetramethylene) segments: some aspects of synthesis

Block copolyurethane networks containing blocks of poly(12-hydroxy stearate) (PTHS) and poly(oxy tetramethylene) (POTM) were realized by two synthesis strategies. In a single-step synthesis, a PTHS-based polyol, viz. ISRO polyol and hydroxy telechelic poly(oxy tetramethylene), were co-cured in the presence of tolylene diisocyanate (TDI) using trimethylol propane (TMP) as crosslinker. In this case, increasing POTM content resulted in an initial improvement in mechanical properties, but enhancing its concentration beyond 20% by weight was detrimental to the properties. At this stage, the cure reaction was found to be incomplete and the partly cured system showed visible phase separation. This has been attributed to the differential reactivities of the OH groups of varying nature present on the polyols towards TDI that could lead to chain-extended homopolyurethane segments accelerating the phase separation. The possible non-uniform distribution of the crosslinker in the two phases and consequent imbalance in OH/NCO rapport might lead to incomplete crosslinking. This problem was overcome by pre-reacting PTHS and hydroxy functional POTM through an esterification reaction to result in a block copolyol. The composition of POTM in the block copolyol was varied using hydroxy functional POTM of different molecular weights, which were synthesized through the cationic ring opening polymerization of tetrahydrofuran. Curing the block copolyol using TDI and TMP resulted in a homogeneous block copolyurethane network. Increasing the concentration and chain length of POTM block was conducive to enhancing both the tensile strength and elongation of the polyurethane network. The phase miscibility of the formed block copolyurethane was inferred from the occurrence of a single glass transition temperature (Tg) for the polymer. Enhancing POTM content decreased the Tg of the copolyurethane in conformation with Fox’s law for a homogeneous copolymer.

Kinetic Studies of Poly(tetrahydrofuran) Epitaxial Film Formed by Polymerization-Induced Epitaxy Using Atomic Force Microscopy

To understand the mechanism of polymer epitaxy during solution polymerization (polymerization-induced epitaxy, PIE), the kinetics of the epitaxial film growth was compared with that of polymerization in solution. The surface coverage and the domain size of epitaxial films as well as the molecular weight of the polymer formed in solution were examined as functions of the reaction time, the monomer concentration, and the initiator concentration. Atomic force microscopy was used to evaluate the coverage and the apparent island size distribution. Cationic ring-opening polymerization of tetrahydrofuran (THF) in dichloromethane at 0 °C on a graphite substrate in the reaction mixture induces an epitaxial film of poly(THF), consisting of 0.5 nm thick, flat, rectangular islands. The reaction time dependence indicates that the film has developed much faster than the polymer growth in solution. When the monomer concentration was varied, no polymer was formed in solution below 3 mol/L, corresponding to the equilibriu...

Ring‐opening polymerization of tetrahydrofuran with rare earth‐contained catalysts

AbstractRare earth trifluoroacetates, Ln(CF3CO2)3 (Ln=thirteen rare earth elements), combined with RnAlH3−n (R=methyl, octyl, n=3; R=ethyl, i‐Butyl, n=2,3) were used as catalysts for the polymerization of tetrahydrofuran (THF). The activity increased by adding propylene oxide (PO), as a promoter, to the polymerization system, producing high molecular weight polytetrahydrofuran (PTHF). The effects of Ln, PO/Ln, and Al/Ln, and others on the polymerization of THF were also studied. © 1993 John Wiley &amp; Sons, Inc.