Varying Feed Ratios Research Articles

Facile synthesis of poly(l -tryptophan) through polycondensation of activated urethane derivatives

A facile and phosgene-free synthetic route to poly(l-tryptophan) 2 by the polycondensation of N-phenoxycarbonyl-l-tryptophan 1 is described. The monomer 1 was synthesized via the carbamylation of tetrabutylammonium salt of L-tryptophan with diphenyl carbonate. The polycondensation proceeded smoothly at 60 °C in N,N-dimethylacetamide in the presence of amines (n-butylamine, diethylamine, and triethylamine) along with the elimination of phenol and carbon dioxide. The structural analysis of the obtained 2 by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry revealed that n-butylamine or diethylamine was successfully incorporated into the chain end of the polypeptide. Furthermore, we have demonstrated the synthesis of a diblock copolymer by utilizing amine-terminated poly(ethylene glycol) as a source of the polyether segment. The chain length of the polypeptide segment was controlled by varying feed ratio between 1 and the amino group of poly(ethylene glycol). © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4565–4571

Branching generation during the free radical copolymerization of p-vinyl benzene sulfonyl chloride with styrene

The branching generation during the free radical copolymerization of chain transfer monomer p-vinyl benzene sulfonyl chloride (VBSC) with styrene was investigated by a simple mathematic model. Chain transfer constant of VBSC was determined to be around 0.3 by fitting the 1H-NMR monitored experimental results with a mathematic model. According to the theoretical analysis, the obtained poly(VBSC) and its copolymers were substantiated to have a grafting-like main chain with residual pendent sulfonyl chloride groups after consuming most of the vinyl groups. The copolymerization results of VBSC with styrene at varied feed ratios demonstrated that conversion of sulfonyl chloride groups was lower than that of the monomer, which was in agreement with the theoretical results. The glass transition temperature, number average molecular weight and distribution of those obtained polymers were primarily investigated. Comparing with other chain transfer monomers, VBSC has a chain transfer constant much closer to unity therefore a more branched polymer is expected. Additionally, the branched polystyrene with residual sulfonyl chloride groups is hopefully to be further used as ATRP macroinitiators or reactive intermediates to synthesize functional polymers with complex structure.

Development of high‐performance networked polymers based on cyclotrimerization of isocyanates: Control of properties by addition of monoisocyanates

Highly heat-resistant networked polymers consisting of isocyanurate moieties have been developed based on cyclotrimerization of isocyanates. To the polymerization system using methylene diphenyl 4,4′-diisocyanate (MDI) as the main component, a series of aromatic monoisocyanates (p-tolylisocyanate, p-trifluoromethylphenylisocyanate, p-tert-butylphenylisocyanate, and p-butylphenylisocyanate) were added with varying feed ratio [MDI]0:[monoisocyanate]0 to achieve successful control of flexibility of thecorresponding networked polymers without serious deterioration of the thermal stability.

Development of high‐performance networked polymers consisting of isocyanurate structures based on selective cyclotrimerization of isocyanates

AbstractSelective and quantitative cyclotrimerization of p‐tolylisocyanate proceeded by using sodium p‐toluenesulfinate as a catalyst and 1,3‐dimethylimidazolidinone as a solvent. Exploitation of this system to the cyclotrimerization of methylene diphenyl 4,4′‐diisocyanate (MDI) permitted formation of the corresponding networked polymer, which was selectively consisted of isocyanurate moiety and thus exhibited excellent thermal stability. Utilization of phenyl isocyanate (PhNCO) as a comonomer with varying feed ratio [MDI]0/[PhNCO]0 allowed successful control of flexibility of the networked polymers, while retaining its high thermal stability. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Inverse thermally reversible gelation-based hydrogels: synthesis and characterization of N-isopropylacrylamide copolymers containing deoxycholic acid in the side chain

A series of water-soluble, thermosensitive copolymers based on N-isopropylacrylamide (NIPAM) and methacrylate derivatives of deoxycholic acid (MEDCA) were synthesized using free radical copolymerization method by varying feed ratios of monomers. The composition ratios and structure of copolymers were determined by 1H NMR spectroscopy. The glass transition temperature was examined by DSC. The thermoresponsive behaviors of polymeric solutions were investigated by turbidity measurement using UV-Visible spectroscopy. The resultant copolymers exhibit systematic changes in their LCSTs as a function of their chemical composition, as the incorporation of amphiphilic comonomers MEDCA results in a lower and broader LCST of the copolymer solution. An aqueous solution of the copolymer above a critical concentration (2 wt%) experiences four distinct phases such as clear solutions, cloud solutions, gel and shrunken gel upon heating. Finally, the mechanism of the phase transitions was tentatively discussed based on the observations.

Synthesis and characterization of thermosensitive and pH‐sensitive poly (N‐isopropylacrylamide‐acrylamide‐vinylpyrrolidone) for use in controlled release of naltrexone

In this article N-isopropylacrylamide (NIPAAm)-acrylamide (AAm)-vinyl pyrrolidone (VP) terpolymers were prepared using free radical copolymerization method by varying feed ratios of monomers. The composition ratio and structure of polymer were determined by NMR and FTIR. The glass transition temperature was examined by DSC. The thermo-responsive behaviors of polymeric solutions were investigated by turbidimetry using UV-Visible spectroscopy. The sol-gel transition of the polymer solutions occurred reversibly within 1 min in response to the temperature. By alternating the monomer feed ratio, the synthesized terpolymers had their own distinctive lower critical solution temperature (LCST). In addition to the thermosensitivity, the terpolymers also showed a response to pH changes. The increase in ionic strength of the buffer solution with addition of salt lowered the LCST of the polymers. The ability to shift the phase transition temperature of the terpolymers provided excellent flexibility in tailoring transitions for specific uses. Swelling experiments were performed on the terpolymer disks in buffer solutions with different pH and ionic strength at varying temperature. We investigated naltrexone release as a model drug in phosphate buffer. Drug loading efficiency was varying from 8.75 to 55%. Gel composition, pH, and ionic concentration affected the drug loading. Finally in vitro drug release studies at 36-37 degrees C indicating 35-70% naltrexone release from terpolymers at the end of 30 days. In addition, these gels sustained naltrexone release for 30 days.

Synthesis of Substituted Polyacetylenes Grafted with Polystyrene Chains by the Macromonomer Method and Their Characterization

Summary: A macromonomer (1) consisting of a polystyrene chain and an acetylenic chain end ( = 2 500, = 1.20) was prepared by atom transfer radical polymerization. Macromonomer 1 was copolymerized with phenylacetylene (2) and propargyl 2-bromopropionate (3) by using Rh catalysts at varying feed ratios from 10 to 50 wt.-% to produce graft copolymers 4 and 5, respectively. The synthesized copolymers 4 and 5 possessed a conjugated polyene main-chain and polystyrene grafts, and contained 11–34 and 16–77 wt.-% of polystyrene with of 61 400–144 000 and 19 300–22 500, respectively. Graft copolymer 4 was a yellow solid and thermally stable up to 225 °C, whereas 5 was a brown solid with weight loss beginning at 175 °C. Graft copolymers 4 and 5 exhibited UV-vis absorption edges at 525 and 425 nm, respectively, which are attributable to the conjugated main-chain structure. Copolymerization of the acetylene-terminated polystyrene-based macromonomer with monosubstituted acetylenes.

Thermosensitive N-isopropylacrylamide– N–propylacrylamide-vinyl pyrrolidone terpolymers: Synthesis, characterization and preliminary application as embolic agents

In this article, thermosensitive N-isopropylacrylamide (NIPAAm)– N-propylacrylamide (NPAAm)–vinyl pyrrolidone (VP) terpolymers (PNINAVP) were prepared by varying feed ratios with free radical copolymerization method. The composition ratios and molecular weights of PNINAVP were examined by NMR and GPC. The thermo-responsive behaviors of copolymer solutions in the absence and with addition of Iohexol, a radiopaque agent, were investigated by differential scanning calorimetry (DSC) and rheometer. The sol–gel transition of the copolymer solutions occurred reversibly within 1 min in response to temperature. Incorporation of Iohexol increased the transition time and transition temperature of PNINAVP solutions; the rheological properties were also influenced. It was observed that at body temperature, PNINAVP and Iohexol could form an integrated bulky hydrogel presumably due to the hydrogen bonding between them, which was favorable for the clinical follow-up and reducing toxic side effects. In vitro embolic model experiment indicated that 5 wt% 16:16:1H PNINAVP solution containing Iohexol displayed a satisfactory embolization effect. This solution was injected into the rete mirabiles (RM) of six swines through a microcatheter. The angiographical results obtained immediately after the operation showed a complete occlusion of the RM, and no recanalization was observed at postoperative month 1. The histological examination demonstrated no acute inflammatory reaction inside the RM and surrounding tissue. This work could provide a beneficial guidance for designing a new temperature-sensitive polymer-based embolic agent.

Growth of cultured seahorses (Hippocampus abdominalis) in relation to feed ration

This investigation examined the effect of varying feed ratios on cultured seahorse (Hippocampus abdominalis) growth and survival using frozen mysids (Amblyops kempii) at daily feed rations of 5, 10, 15 or 20% wet body weight. Feeding these different feed rations did not result in any significant difference in seahorse standard length after 3 months. However, seahorses fed the 10–20% rations were heavier and with higher condition factor (CF). Based on the total amount of frozen mysids offered to the seahorses, the food conversion ratio (FCR) became less efficient with increasing feed ration. However, when the actual mysid consumption was factored in there were no significant differences in FCR. There was a significant difference in daily specific growth rate (SGR), with the 5% ration having the lowest SGR. On a cost/benefit basis, based on the total amount of mysids offered the most cost effective ration for daily length and weight increase was the 5% ration. With actual mysid consumption taken into account, cost/benefit value favoured the 5 and 10% feed rations. Survival was 100% across all treatments. Based on this, a feed ration of 5–10% wet body weight per day of frozen mysids is recommended for cultured H. abdominalis

Stimuli sensitive copolymer poly(N‐tert‐butylacrylamide‐ran‐acrylamide): Synthesis and characterization

AbstractTemperature sensitive random linear and crosslinked copolymers of N‐tert‐butylacrylamide (NTBA) and acrylamide (Am) were synthesized by the solution polymerization method, using regulated dosing of comonomer Am having a higher reactivity ratio (rAm = 1.5) than NTBA (rNTBA = 0.5). Copolymers with varying feed ratios of NTBA and Am (80 : 20 to 20 : 80 mol %) were synthesized and characterized. For the synthesis of copolymer hydrogels, N′, N‐methylene bisacrylamide (MBA) (1.13 mol %) was used along with monomers. The effect of composition on transition properties was evaluated for the linear copolymers and their hydrogels. A definite trend was observed. The incorporation of a higher percentage of the hydrophilic comonomer Am in the structure resulted in the shifting of the transition temperature towards a higher value. The transition temperatures of the copolymers synthesized with feed compositions of 80 : 20, 70 : 30, 60 : 40, 50 : 50, 40 : 60, 30 : 70, and 20 : 80 mol % were found to be 2, 10, 19, 27, 37, 45, and 58°C, respectively. Differential scanning calorimetry (DSC) studies confirmed the formation of random copolymers. The copolymers synthesized with a monomer feed ratio of 50 : 50 with regulated dosing showed a single glass transition temperature (Tg) at 168°C, while the copolymer synthesized with full dosing of Am at the beginning of the reaction showed two Tgs, at 134 and 189°C. The copolymer samples were analyzed by Fourier transform infrared spectroscopy (FTIR) for ascertaining the composition. The composition of the copolymers followed the trend of the feed ratio, but the incorporation of NTBA in the copolymers was found to be lower than the feed ratio because of lower than quantitative yields of the reactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 672–680, 2005

Poly[(styrene- co- p-methylstyrene)- b-isobutylene- b-(styrene- co- p-methylstyrene)] triblock copolymers. 1. Synthesis and characterization

The synthesis of poly(isobutylene) (PIB)-based triblock copolymers having copolymer end blocks containing styrene and p-methylstyrene ( pMSt) repeat units was investigated in an attempt to minimize chain-coupling reactions that occur at the 4-position on styrene repeat units during end block polymerization. Model end block copolymerizations using varying feed ratios of styrene and pMSt were conducted, and it was determined by 1H NMR analysis that the addition of pMSt to the living chain end was favored slightly at low conversion. However, DSC revealed a single T g that increased with increasing pMSt content verifying the absence of blockiness in the microstructure. Poly[(styrene- co- pMSt)- b-isobutylene- b-(styrene- co- pMSt)] triblock copolymers were synthesized using varying feed ratios of styrene and pMSt. The rate of end block propagation increased with increasing pMSt in the feed, and the end block copolymerizations initiated by PIB displayed longer reaction times and more curvature in their first order plots than did the model end block copolymerizations initiated by TMPCl. This effect was attributed to lower ionization equilibrium constant and higher degree of termination caused by the more non-polar local reaction medium provided by the PIB center blocks in block copolymerization. GPC analysis of the final BCPs revealed a decrease in a high molecular weight peak representing the chain-coupled product as the concentration of pMSt in the feed was increased.

Stimuli sensitive copolymer poly( N- tert-butylacrylamide- ran-acrylamide): processing into thin films and their transitional behaviour

Temperature sensitive polymer hydrogels are being extensively studied because of their potential applications in biomedical, robotics, and chemical industry. However, major hurdles in their development have been their slow response, low efficiency, and poor mechanical properties. One of the main reasons for these shortcomings is the difficulty of processing them into mechanically fine structures in polymer gel form. In this work, a novel approach has been developed to process temperature sensitive copolymers based on acrylamide into mechanically stable thin films. A series of temperature sensitive random linear copolymers of N- tert-butylacrylamide (NTBA) and acrylamide (Am) were synthesized by solution polymerization method, using regulated dosing of comonomer Am having a higher reactivity ratio ( r Am=1.5) than NTBA ( r NTBA=0.5). Copolymers with varying feed ratios of NTBA and Am (80:20 to 20:80 mol%) were synthesized and characterized. The actual incorporation of less reactive comonomer NTBA was found to be lower than the feed and was found to vary between 75 mol% with feed of 80 and 11 mol% for a feed of 20%. Linear copolymer with 40:60 feed ratio of NTBA and Am monomers, with actual incorporation of NTBA to the extent of 27 mol%, was selected for processing. The copolymer films of thickness in the range of 10–200 microns could be obtained from aqueous solution in the presence of citric acid or 1,2,3,4-butane tetracarboxylic acid as crosslinkers and sodium hypophosphite as catalyst. Subsequently, the films were crosslinked at 150–160 °C to obtain mechanically strong insoluble films. The crosslinks were formed between reactive amide side groups of the acrylamide moiety of the polymer and the carboxylic acid group of the crosslinker. The transition temperatures of the crosslinked films were found to shift towards the lower temperature from 37 °C (in linear copolymer) to 22–25 °C. High surface to volume ratio of the prepared films lead to significant increase in swelling percentage from 490 to 2980% and faster response time from 1280 min (in the first cycle) to 5 min compared to polymerized-gel samples (2 mm disc) of the same composition.

Magnetoelectrochemistry of Nitrothiophenolate-Functionalized Gold Nanoparticles

The electrochemical behaviors of n-decanethiolate-protected gold (C10Au) nanoparticles that had been exchanged with p-nitrothiophenolate (NTP) ligands at varied feed ratios were investigated in an external magnetic field (0−0.5 T). It was found that the NTP voltammetric currents are dependent on the electrode orientation and the intensity of the magnetic field. When the concentration of NTP in the particle is low (e.g., 10 or 30% exchange ratio), the currents at angles of 0 and 180° are greater than those at 90 and 270°. However, when the initial feed ratio is increased to 50%, the currents at angles of 0 and 180° are smaller than those at 90 and 270°. While these observed phenomena are ascribed to the magnetic field effects on nanoparticle mass transfer, their mechanistic origins are different. The former is attributable to the field-enhanced magnetoconvection due to the formation of an interfacial gradient of magnetic susceptibility (concentration), and the latter arises from magnetohydrodynamic interac...

Characterization of poly(trimethylene/butylene terephthalate) copolymer prepared by the copolycondensation of bis(3-hydroxypropyl terephthalate) and bis(4-hydroxybutyl terephthalate)

Homopolymers and copolymers were synthesized by polycondensation and copolycondensation, with varying feed ratios of bis(3-hydroxypropyl terephthalate) (BHPT) and bis(4-hydroxybutyl terephthalate) (BHBT) at 270°C. In addition, in the mol ratio of 1:1, copoly(trimethylene terephthalate/butylene terephthalate) [P(TT/BT)], with reaction times of 5, 10, 20, 30, and 60 min, was synthesized to identify the chain-growth process of the copolymers. From differential scanning calorimetry (DSC) data, it was found that a random copolymer might be formed during copolycondensation. The molecular structure of copolymers, formed through the interchange reaction of BHPT and BHBT, was investigated using carbon nuclear magnetic resonance spectroscopy (13C-NMR). We calculated the sequence-length distributions of trimethylene and butylene sequences and randomness in the copolymers using 13C-NMR data. From the values of the number-average sequence length calculated, it was determined that a random copolymer was produced: This result coincides with previous DSC data. The lateral spacing of the unit cell of the copolymer increased slowly when the mol percent of one monomer was increased to that of the other monomer, indicating broadening of the unit cell by lateral distortion. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2200–2205, 2003

Synthesis of novel amphiphilic star-shaped poly(ε-caprolactone)- block-poly( N-(2-hydroxypropyl)methacrylamide) by combination of ring-opening and chain transfer polymerization

Novel amphiphilic star-shaped block copolymer, star-poly(ε-caprolactone)- block-poly( N-(2-hydroxypropyl)methacrylamide), was synthesized and characterized. Star-block copolymers with varying feed ratios were prepared by free radical polymerization of N-(2-hydroxypropyl)methacrylamide in the presence of a novel biodegradable, macromolecular chain-transferring agent star-poly(ε-caprolactone)-tetrakis-thiol. All star-block copolymers self-assembled in aqueous solutions to form unimodal micelles of 100–150 nm size. Micelle size was independent of polymer concentration. The critical aggregation concentrations of the polymers were in the range of 1–2.5 mg/l. The partition equilibrium constant of pyrene in the hydrophobic core of micelles was comprised between 5 and 8×10 5. The star-block copolymer micelles were loaded by a dialysis procedure with 5–12% (w/w) of a model poorly water-soluble drug (indomethacin). These star-block copolymers could prove useful as nanocarriers for the solubilization and transport of hydrophobic drugs. Star-shaped macromolecular chain-transferring agent reported in this work can also find application in the synthesis of a variety of novel biodegradable star-block copolymers.

Application of ketenes to well-defined polyester synthesis. III. Living anionic polymerization of ethyl(4-methoxyphenyl)ketene?Development of polyester having masked phenol side chain

A novel ketene, ethyl(4-methoxyphenyl)ketene (EMPK), was synthesized by the dehydrochlorination of 2-(4-methoxyphenyl)butanoyl chloride. The anionic polymerizations of EMPK by butyllithium in tetrahydrofuran at −20 °C were carried out with a varying feed ratio to give the corresponding polyesters having predictable molecular weights and narrow molecular weight distributions, quantitatively. The selective formation of the polyester was confirmed by IR analysis, and the reductive degradation of the polymer was supported by lithium–aluminium hydride. The second feed of the monomer (after the first stage of polymerization) resulted in the formation of the polymer with the expectedly increased molecular weight and low polydispersity to strongly support the living mechanism of this polymerization. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1596–1600, 2001

Alkanethiolate-Protected PbS Nanoclusters: Synthesis, Spectroscopic and Electrochemical Studies

A series of alkanethiolate-passivated PbS nanoparticles were synthesized with varied feed ratios of the starting reactants, lead acetate and alkanethiols, and characterized by using a variety of spectroscopic and electrochemical techniques. Transmission electron microscopic studies revealed that, of all the samples prepared, the particle size mainly fell into the range of 2−4 nm in diameter, with mostly spherical shape and modest dispersity. In addition, the particles were found to be quite stable where the particle size varied only slightly during particle growth. UV−Vis spectroscopy showed an absorption edge at a wavelength between 700 and 800 nm for the larger particles (>3 nm in diameter), while for the smaller particles (2.5 nm in diameter), the absorption edge was found at 560 nm, which was consistent with the size-dependent quantum confinement effect of PbS nanoparticles. Photoluminescence studies were carried out by measuring the excitation and emission spectra of the PbS nanoparticles in solutions, where the fluorescence was found at around 804 nm and the peak intensity appeared to be depressed greatly by the presence of transition-metal (e.g., Au, Ag, and Pd) nanoparticles, despite the relatively weak absorption of metal particles at the red end. Electrochemical studies of the PbS nanoparticles in solution revealed an analogue to the Coulomb blockade that arose from the particle band gap structure within the potential range of from −0.8 to +0.8 V, and at potentials beyond this range, cathodic reduction as well as anodic dissolution of PbS resulted in a series of voltammetric waves, where rather significant overpotentials were observed as compared to those in aqueous media.

Novel Spontaneous Polymer Formation from Acetaldehyde Azine and Maleic Anhydride via Radical Mechanism

A THF-insoluble polymeric product was obtained by the reaction between acetaldehyde azine (AcAz) and maleic anhydride (MAnh) without any initiator. The reduced viscosity values for this product indicate polymer formation from AcAz and MAnh. Results of the reactions between AcAz and MAnh at varying feed ratios of AcAz indicate that the polymer is formed mainly by reaction between equimolar amounts of AcAz and MAnh. (2Z)-4-{1-(5-Methyl-2-pyrazolinyl)}-4-oxo-2-butenoic acid (compound 1), a one-to-one adduct of AcAz with MAnh, was isolated as a crystalline compound from the THF-soluble fraction of the reaction mixture. Comparing the spectroscopic results for the polymer with those for compound 1 and 4-{1-(5-methyl-2-pyrazolinyl)}-4-oxobutanoic acid (compound 2), a one-to-one adduct of AcAz with SAnh, the polymer from AcAz and MAnh was found to be formed mainly by polymerization of compound 1 through the CC bond. Results of the polymerizations of compound 1 using typical initiators show compound 1 can be polym...

Evaluation of poly(acrylic acid-co-ethylhexyl acrylate) films for mucoadhesive transbuccal drug delivery: factors affecting the force of mucoadhesion

Based on the premise that similar surface properties between the adhesive and the substrate would yield a strong adhesive bond, copolymers of acrylic acid (AA) and 2-ethylhexyl acrylate (EHA), P(AA-co-EHA), were designed and synthesized for buccal mucoadhesion. A series of linear copolymers with varying feed ratios of the two monomers (AA and EHA) were synthesized through free radical copolymerization at 69±0.5°C using azobis(isobutyronitrile) (AIBN) as initiator. The reactions were carried out in THF under nitrogen for 24 h. The glass transition temperatures, T g, of the copolymers were determined using DSC. The adhesion studies were conducted to determine the effects of copolymer composition, contact time between the substrate and the adhesive, and crosshead speed on mucoadhesive performance of the copolymer films using a computer interfaced Instron material testing system. The glass transition temperature of the copolymers decreased with increasing EHA content. Wet glass surface as substrate was shown not to be a good substrate model for adhesion determination studies. The copolymer composed of 46:54 mol.% AA:EHA (an almost 1:1 ratio in the repeat units) yielded the highest mucoadhesive force in contact with porcine buccal mucosa which was significantly greater ( P<0.05) than that of poly(acrylic acid) (PAA) (used as positive control). The mucoadhesive force for all copolymers studied was significantly ( P<0.05) greater than that of the negative control (backing material without copolymer film) except for the EHA homopolymer. Crosshead speed increased mucoadhesive force linearly and had a more pronounced effect on the mucoadhesive performance than time of contact between the adhesive and the substrate.

Living anionic polymerization of ethylphenylketene: A novel approach to well-defined polyester synthesis

A living polymerization of ethylphenylketene (EPK) was accomplished. When polymerization of EPK was carried out with butyllithium as an initiator in tetrahydrofuran (THF) at -20 °C, EPK was completely consumed within 5 min, and the corresponding polyester with narrow molecular weight distribution (M w /M n ∼ 1.1) was obtained almost quantitatively. Kinetic study of the polymerization at -78 °C revealed that conversion of EPK agreed with the first-order kinetic equation, and that M n of the polymer increased in virtually direct proportion to the conversion. Along with these results, successful results in postpolymerization at -20 °C strongly supported living mechanism of the present polymerization. Further, lithium alkoxides having a methoxy group, styryl moiety, and nitroxyl radical, also successfully initiated polymerization of EPK to afford the corresponding polymers having functional initiating ends. In the polymerization with varying feed ratio [EPK] 0 /[initiator] 0 , the linear relationship between the feed ratio and M n of the obtained polymer was observed, while maintaining narrow M w /M n .