Synthesis of star poly(1,3‐cyclohexadiene): Grafting reaction of poly(1,3‐cyclohexadienyl)lithium onto C60

The grafting reaction of poly(1,3‐cyclohexadienyl)lithium onto fullerene‐C₆₀ (C₆₀) was strongly affected by the nucleophilicity of poly(1,3‐cyclohexadiene) (PCHD) carbanions and the polymer chain microstructure, and progressed via step‐by‐step reactions. A star‐shaped PCHD, having a maximum of four arms, was obtained from poly(1,3‐cyclohexadienyl)lithium composed of all 1,4‐cyclohexadiene (1,4‐CHD) units. The rate of the grafting reaction was accelerated by the addition of amine. The grafting density of PCHD arms onto C₆₀ decreased with an increase in the molar ratio of 1,2‐cyclohexadiene (1,2‐CHD) units. The electron‐transfer reaction from PCHD carbanions to C₆₀ did not occur in either a nonpolar solvent or a polar solvent. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3282–3293, 2008.     

Dehydrogenation of poly(1,3‐cyclohexadiene)–polystyrene binary block copolymers

The dehydrogenation of poly(1,3‐cyclohexadiene)–polystyrene binary block copolymers obtained by anionic copolymerization with alkyllithium/amine systems was investigated for the first time. The dehydrogenation of the poly(1,3‐cyclohexadiene) block, which was composed of 1,2‐cyclohexadiene (1,2‐CHD) and 1,4‐cyclohexadiene (1,4‐CHD) units, was strongly affected by the polymer chain structure. The existence of 1,2‐CHD units prevented the dehydrogenation of the poly(1,3‐cyclohexadiene) block in the binary block copolymer. The rate of dehydrogenation was fast on a long sequence of 1,4‐CHD units, whereas it was relatively slow for 1,2‐CHD/1,4‐CHD (≈1/1) unit sequences. The bonding of the polystyrene block to the polymer chain effectively improved not only the rate of dehydrogenation of a long sequence of 1,4‐CHD units but also that of the polymer chain with a high content of 1,2‐CHD units. The dehydrogenation of a poly(1,3‐cyclohexadiene) block containing a small number of 1,2‐CHD units progressed via step‐by‐step reactions. The dehydrogenation of a long sequence of 1,4‐CHD units proceeded as the first step. Subsequently, in the second step, the 1,2‐CHD/1,4‐CHD (≈1/1) unit sequences remaining in the polymer chain were dehydrogenated. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3526–3537, 2006     

Oxidation and epoxidation of poly(1,3‐cyclohexadiene)

Poly(1,3‐cyclohexadiene) (PCHD) derivatives were synthesized via facile chemical modification reactions of the residual double bond in the repeat unit. The oxidation and degradation of PCHD was investigated to enable subsequent controlled epoxidation reactions. PCHD exhibited a 15% weight loss at 110 °C in the presence of oxygen. The oxidative degradation, demonstrated by gel permeation chromatography (GPC) and ¹H NMR spectroscopy, was attributed to main‐chain scission. Aldehyde and ether functional groups were introduced into the polymer during the oxidation process. PCHD was quantitatively epoxidized in the absence of deleterious oxidation with meta‐chloroperoxybenzoic acid. ¹H and ¹³C NMR spectroscopy confirmed that polymers with controlled degrees of epoxidation were reproducibly obtained. Epoxidized PCHD exhibited a glass‐transition temperature at 154 °C, which was slightly higher than that of a PCHD precursor of a nearly equivalent molecular weight. Moreover, GPC indicated the absence of undesirable crosslinking or degradation, and the molecular weight distributions remained narrow. The thermooxidative stability of the fully epoxidized polymer was compared to that of the PCHD precursor, and the epoxidized PCHD exhibited an initial weight loss at 250 °C in oxygen, which was 140 °C higher than the temperature for PCHD. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 84–93, 2003     

Oxidation of poly(1,3‐cyclohexadiene): Influence of the polymer chain structure

The influence of the microstructure on the oxidation of poly(1,3‐cyclohexadiene) (PCHD) homopolymer, obtained by anionic polymerization with alkyllithium/amine systems, was investigated for the first time. PCHD has a structure consisting of a main chain formed by 1,2‐addition (the 1,2‐CHD unit) and 1,4‐addition (the 1,4‐CHD unit). The molar ratio of 1,2‐CHD/1,4‐CHD units in the polymer chain strongly influenced the extent of oxidation of PCHD. A polymer chain with a high content of 1,4‐CHD units was easily oxidized by air and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ). In contrast, the progress of oxidation was prevented in the case of PCHD containing 52% of 1,2‐CHD units. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 837–845, 2006     

Anionic polymerization of 1,3‐cyclohexadiene with alkyllithium/amine system in an aromatic hydrocarbon solvent: Predominant formation of 1,2‐addition product

Steric hindrance of the amine strongly affected the formation of the dominant 1,2‐addition product from the anionic polymerization of 1,3‐cyclohexadiene (1,3‐CHD) initiated by the alkyllithium (RLi)/amine system in an aromatic hydrocarbon solvent. 1,2‐Cyclohexadiene (1,2‐CHD)/1,4‐cyclohexadiene (1,4‐CHD) unit molar ratios from 85/15 to 93/7 were obtained using an RLi/N,N,N′,N′‐tetramethylethylenediamine (TMEDA) system in toluene. The C? Li bonds of poly(1,3‐cyclohexadienyl)lithium (PCHDLi)/TMEDA complex in toluene appeared to be strongly polarized with small steric hindrance. Intermolecular forces contributing to the aggregation were strong for high‐molecular‐weight poly(1,3‐cyclohexadiene) (PCHD) consisting of almost all 1,2‐CHD units. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6604–6611, 2008     

Influence of tertiary diamines on the synthesis of high‐molecular‐weight poly(1,3‐cyclohexadiene)

The living synthesis of poly(1,3‐cyclohexadiene) was performed with an initiator adduct that was synthesized from a 1:2 (mol/mol) mixture of N,N,N′,N′‐tetramethylethylenediamine (TMEDA) and n‐butyllithium. This initiator, which was preformed at 65 °C, facilitated the synthesis of high‐molecular‐weight poly(1,3‐cyclohexadiene) (number‐average molecular weight = 50,000 g/mol) with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight = 1.12). A plot of the kinetic chain length versus the time indicated that termination was minimized and chain transfer to the monomer was eliminated when a preformed initiator adduct was used. Chain transfer was determined to occur when the initiator was generated in situ. The polymerization was highly sensitive to both the temperature and the choice of tertiary diamine. The use of the bulky tertiary diamines sparteine and dipiperidinoethane resulted in poor polymerization control and reduced polymerization rates (7.0 × 10⁻⁵ s⁻¹) in comparison with TMEDA‐mediated polymerizations (1.5 × 10⁻⁴ s⁻¹). A series of poly(1,3‐cyclohexadiene‐block‐isoprene) diblock copolymers were synthesized to determine the molar crossover efficiency of the polymerization. Polymerizations performed at 25 °C exhibited improved molar crossover efficiencies (93%) versus polymerizations performed at 40 °C (80%). The improved crossover efficiency was attributed to the reduction of termination events at reduced polymerization temperatures. The microstructure of these polymers was determined with ¹H NMR spectroscopy, and the relationship between the molecular weight and glass‐transition temperature at an infinite molecular weight was determined for polymers containing 70% 1,2‐addition (150 °C) and 80% 1,4‐addition (138 °C). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1216–1227, 2005     

Polymerization of 1,3‐cyclohexadiene with nickel/MAO catalytic systems

The polymerization of 1,3‐cyclohexadiene with nickel bis(acetylacetonate) activated by methylaluminoxane affords poly(1,3‐cyclohexadiene) in high yields; the same catalyst is unable to polymerize larger conjugated cyclic diolefins or copolymerize 1,3‐cyclohexadiene with styrene. In the latter case, the homopolymer of the diolefin is obtained. The catalyst activity increases with increasing reaction temperature, nickel concentration, and aluminum/nickel ratio or with the addition of triisobutylaluminum to the reaction medium. The obtained poly(1,3‐cyclohexadiene) samples are high‐melting crystalline polymers (melting temperature ∼ 320 °C) that are insoluble in all common organic solvents. With bis(cyclopentadienyl)nickel in place of nickel bis(acetylacetonate), the activity is much lower, but the polymer is more stereoregular, as indicated by the slightly higher value of the melting temperature. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3004–3009, 2000     

Synthesis of soluble poly(para‐phenylene) with a long polymer chain: Characteristics of regioregular poly(1,4‐phenylene)

Soluble poly(para‐phenylene) having a long polymer chain (more than six repeat units) was synthesized with a tert‐butyl end‐group (t‐PPP) and was found to have improved solubility and excellent optical properties. Poly(1,3‐cyclohexadiene) (PCHD) consisting of only 1,4‐cyclohexadiene (1,4‐CHD) units was synthesized with a tert‐butyl end‐group (t‐PCHD), and completely dehydrogenated to obtain t‐PPP. This end‐group effectively prevented the crystallization of t‐PPP, and polymers containing up to 16 repeat units were soluble in tetrahydrofuran. Soluble t‐PPP obtained had an ability to form a tough thin film prepared by spin‐coating method. Optical analyses of t‐PPP provided strong evidence for a linear polymer chain structure. A block copolymer of t‐PPP and a soluble polyphenylene (PPH) was then synthesized, and the excellent optical properties were retained by this block copolymer along with its solubility. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5223–5231, 2008     

Living anionic polymerization of (E)‐1,3‐pentadiene and (Z)‐1,3‐pentadiene isomers

The anionic polymerization of (E)‐1,3‐pentadiene (EP) and (Z)‐1,3‐pentadiene (ZP) together with mixture of the E/Z isomers are investigated, respectively. The kinetic analysis shows that the activation energy for EP (86.17 kJ/mol) is much higher than that for ZP (59.03 kJ/mol). GPC shows that it is the EP rather than the ZP isomer that undergoes anionic living polymerization affording quantitative products of the polymers with well‐controlled molecular weights and narrow molecular weight distributions (1.05 ≤? ≤ 1.09). In addition, THF as polar additive has proved its validity to reduce the molecular weight distribution of poly(ZP) from 1.38 to as low as 1.19. The microstructure and sequence distributions of polypentadiene are characterized by ¹H NMR and quantitative ¹³C NMR. Finally, the distinctive reaction activity of two isomers can be elucidated by two different mechanisms which involve the presence of four forms of zwitterions for EP and the typical [1,5]‐sigmatropic hydrogen‐shift phenomenon for ZP. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2291–2301     

Microphase‐separated structure of 1,3‐cyclohexadiene/butadiene triblock copolymers and its effect on mechanical and thermal properties

We report the effect of microphase‐separated structure on the mechanical and thermal properties of several poly(1,3‐cyclohexadiene‐block‐butadiene‐block‐1,3‐cyclohexadiene) triblock copolymers (PCHD‐block‐PBd‐block‐PCHD) and of their hydrogenated derivatives: poly(cyclohexene‐block‐ethylene/butylene‐block‐cyclohexene) triblock copolymers (PCHE‐block‐PEB‐block‐PCHE). Both mechanical strength and heat‐resistant temperature (ex. Vicat Softening Temperature: VSPT) tended to increase with an increase in the 1,3‐cyclohexadiene (CHD)/butadiene ratio. On the other hand, heat resistance of the hydrogenated block copolymer was found to be higher than that of the unhydrogenated block copolymer. However, the mechanical strength was lower than those of the unhydrogenated block copolymer with the same ratio of CHD to butadiene. To clarify the relationship between the higher order structures of those block copolymers and their properties, we observed the microphase‐separated structure by transmission electron microscope (TEM). Hydrogenated block copolymers were found to have more finely dispersed microphase‐separated structures than those of the unhydrogenated block copolymers with the same CHD/Bd ratios through the use of TEM and the small‐angle X‐ray scattering (SAXS) technique. Those results indicated that the segregation strength between the PCHE block sequence and the PEB block sequence increased, depending on hydrogenation of the unhydrogenated precursor. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 13–22, 2001     

Cationic ring‐opening polymerization of novel 1,3‐dehydroadamantanes with various alkyl substituents: Synthesis of thermally stable poly(1,3‐adamantane)s

Cationic ring‐opening polymerizations of 5‐alkyl‐ or 5,7‐dialkyl‐1,3‐dehydroadamantanes, such as 5‐hexyl‐ ( 4 ), 5‐octyl‐ ( 5 ), 5‐butyl‐7‐isobutyl‐ ( 6 ), 5‐ethyl‐7‐hexyl‐ ( 7 ), and 5‐butyl‐7‐hexyl‐1,3‐dehydroadamantane ( 8 ), were carried out with super Brønsted acids, such as trifluoromethanesulfonic acid or trifluoromethanesulfonimide in CH₂Cl₂ or n‐heptane. The ring‐opening polymerizations of inverted carbon–carbon bonds in 4–8 proceeded to afford corresponding poly(1,3‐adamantane)s in good to quantitative yields. Poly( 4–8 )s possessing alkyl substituents were soluble in 1,2‐dichlorobenzene, although a nonsubstituted poly(1,3‐adamantane) was not soluble in any organic solvent. In particular, poly( 8 ) exhibited the highest molecular weight at around 7500 g mol^?1 and showed excellent solubility in common organic solvents, such as THF, CHCl₃, benzene, and hexane. The resulting poly( 4–8 )s containing adamantane‐1,3‐diyl linkages showed good thermal stability, and 10% weight loss temperatures (T₁₀) were observed over 400 °C. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4111–4124     

A new insight into the mechanism of 1,3‐dienes cationic polymerization. II. Structure of poly(1,3‐pentadiene) synthesized with tBuCl/TiCl4 initiating system

The microstructure of poly(1,3‐pentadiene) synthesized by cationic polymerization of 1,3‐pentadiene with ^tBuCl/TiCl₄ initiating system is analyzed using one‐dimensional‐ and two‐dimensional‐NMR spectroscopy. It is shown that unsaturated part of chain contains only homo and mixed dyads with trans?1,4‐, trans?1,2‐, and cis?1,2‐structures with regular and inverse (head‐to‐head or tail‐to‐tail) enchainment, whereas cis?1,4‐ and 3,4‐units are totally absent. The new quantitative method for the calculation of content of different structural units in poly(1,3‐pentadiene)s based on the comparison of methyl region of ¹³C NMR spectra of original and hydrogenated polymer is proposed. The signals of tert‐butyl head and chloromethyl end groups are identified in a structure of poly(1,3‐pentadiene) chain and the new approaches for the quantitative calculation of number‐average functionality at the α‐ and ω‐end are proposed. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3297–3307     

Synthesis of soluble single‐walled carbon nanotubes with poly (1,3‐cyclohexadiene): Grafting poly(1,3‐cyclohexadienyl)lithium onto a solid surface

The first‐ever grafting of poly(1,3‐cyclohexadiene) (PCHD) onto single‐walled carbon nanotubes (SWNTs) was accomplished by reaction with poly(1,3‐cyclohexadienyl)lithium. The rate of this reaction was especially slow due to the heterogeneous nature of the reaction system. The concentration of active carbons available for reaction with PCHDLi on the solid surface of the SWNTs was found to be approximately 2.0 mol %. The mass of PCHD attached to the SWNTs was effectively controlled by varying the molecular weight of the PCHD. The resulting PCHD‐grafted SWNTs exhibited excellent solubility in organic solvent, maintaining a highly stable homogeneous dispersion even after 3 months. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Functionalization of diamond (001)‐2 × 1 surface by cycloaddition of 1,3‐cyclohexadiene: A theoretical study

Density functional theory calculations have been used to study [4 + 2] and [2 + 2] cycloaddition reaction between 1,3‐cyclohexadiene and diamond (001)‐2 × 1 surface. The calculations revealed four possible reaction pathways for 1,3‐cyclohexadiene with the surface dimmers of diamond. Full geometry‐optimized structures were obtained for all products, including intradimer and interdimer reaction products. These results were analyzed both in terms of the total energy values and the detailed optimized geometries. We found that the intradimer [4 + 2] product is energetically favored over the other products, and the barrier to intradimer [4 + 2] addition is lower than the other additions, so the intradimer [4 + 2] product is expected to be the dominant product on the surface. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Thermal stability of a star‐shaped poly(1,3‐cyclohexadiene)

A star‐shaped poly(1,3‐cyclohexadiene) (PCHD) with a fullerene‐C₆₀ (C₆₀) core (C₆₀‐PCHD) was prepared to examine the thermal stability of the covalent bond between the C₆₀ and PCHD arm in the C₆₀‐PCHD. The covalent bond between the C₆₀ and PCHD arm formed by a 1,2‐cyclohexadiene (CHD) unit on the C₆₀ was stronger than that formed by a 1,4‐CHD unit. The double bond in the CHD unit adjoining the C₆₀ core was a key structure for the stability of that covalent bond. The hydrogenated C₆₀‐PCHD, which did not contain a double bond, possessed significantly higher thermal stability compared to C₆₀‐PCHD. The mechanism of elimination of PCHD arm molecules from the C₆₀ core was thought to proceed via a 1,5‐sigmatropic H‐shift. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2132–2142, 2009     

Synthesis of a series of SG1 2‐[N‐tert‐butyl‐N‐(1‐diethoxyphosphoryl‐2,2‐dimethylpropyl)aminoxyl] based alkoxyamines,SG1‐CH(Me)CO2R,and measurement of the homolysis rate constants of the C?ON bond

During nitroxide‐mediated polymerization, the polymerization time decreases with an increasing rate constant of the cleavage of the NO? C bond of dormant alkoxyamines. Thus, knowledge of the factors influencing this cleavage is of considerable interest. We have prepared a series of SG1 2‐[N‐tert‐butyl‐N‐(1‐diethoxyphosphoryl‐2,2‐dimethylpropyl)aminoxyl] based alkoxyamines [SG1‐CH(Me)CO₂R] with various R groups (alkyl or aryl) and measured the homolysis rate constants (k_d). k_d decreases with the bulkiness and increases with the polarity of the R group. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3504–3515, 2004     

Hydrocarbon polymers containing six-membered rings in the main chain. Microstructure and properties of poly(1,3-cyclohexadiene)

The relationship between the microstructure and the properties of poly(1,3-cyclohexadiene)s, obtained by living anionic polymerization with an alkyllithium/amine system, and their hydrogenated derivatives are reported. The 1,2-bond/1,4-bond molar ratio of poly(1,3-cyclohexadiene) was determined by measuring 2D-NMR with the H H COSY method. The glass transition temperature of poly(1,3-cyclohexadiene) was found to rise with an increase in the ratio of 1,2-bonds to 1,4-bonds or with an increase of the number average molecular weight. The 1,2-bond of the polymer chain gives a high flexural strength and heat distortion temperature. Hydrogenated poly(1,3-cyclohexadiene) has the highest T_g (231°C) among all hydrocarbon polymers ever reported. 1,3-Cyclohexadiene–butadiene–1,3-cyclohexadiene triblock copolymer and 1,3-cyclohexadiene–styrene–1,3-cyclohexadiene triblock copolymer have high heat resistance and high mechanical strength. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1657–1668, 1998     

Diblock copolymers of polystyrene‐b‐poly(1,3‐cyclohexadiene) exhibiting unique three‐phase microdomain morphologies

The synthesis and molecular characterization of a series of conformationally asymmetric polystyrene‐block‐poly(1,3‐cyclohexadiene) (PS‐b‐PCHD) diblock copolymers (PCHD: ～90% 1,4 and ～10% 1,2), by sequential anionic copolymerization high vacuum techniques, is reported. A wide range of volume fractions (0.27 ≤ ?_PS ≤ 0.91) was studied by transmission electron microscopy and small‐angle X‐ray scattering in order to explore in detail the microphase separation behavior of these flexible/semiflexible diblock copolymers. Unusual morphologies, consisting of PCHD core(PCHD‐1,4)–shell(PCHD‐1,2) cylinders in PS matrix and three‐phase (PS, PCHD‐1,4, PCHD‐1,2) four‐layer lamellae, were observed suggesting that the chain stiffness of the PCHD block and the strong dependence of the interaction parameter χ on the PCHD microstructures are important factors for the formation of this unusual microphase separation behavior in PS‐b‐PCHD diblock copolymers. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1564–1572     

Isomer‐dependent properties of poly(vinyl pyridine)‐based films grown on copper surfaces

The effect of poly(2‐vinyl pyridine) (P2VP) and poly(4‐vinyl pyridine) (P4VP) isomers on the growth of surface films on copper substrates was studied by electrochemical, spectroscopic, thermogravimentric, and microscopic methods. In acid environment (3% v/v acetic acid) and in the presence of KSCN, electrochemically generated copper cations reacted rapidly with SCN^? and P2VP or P4VP, yielding coordination compounds, which deposited onto copper surfaces as films. The characteristics of such polymer–metal complexes (films) were markedly isomer‐dependent. Cu(I)/P2VP/SCN^? complexes with monovalent cations and sulfur‐coordinated thiocyanate were obtained in the presence of P2VP, whereas the formation of Cu(II)/P4VP/SCN^? complexes with divalent cations and nitrogen‐coordinated thiocyanate was observed in the presence of P4VP. Interestingly, similar physical–chemical properties (electronic structure, stoichiometry, and thermal behavior) were observed for materials synthesized by electrochemical and chemical methods. These results suggest, therefore, that control over the surface properties of copper substrates can be achieved using electrosynthesized films based on different PVP isomers. Besides acting as effective protective barriers against aggressive media and thus reducing the metal dissolution (corrosion) kinetics, these materials are potentially attractive for other applications in which surface properties are paramount, such as in catalysis. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 215–225, 2009     

Synthesis and characterization of well‐defined ABC 3‐Miktoarm star‐shaped terpolymers based on poly(styrene), poly(ethylene oxide), and poly(ϵ‐caprolactone) by combination of the “living” anionic polymerization with the ring‐opening polymerization

A series of well‐defined ABC 3‐Miktoarm star‐shaped terpolymers [Poly(styrene)‐Poly(ethylene oxide)‐Poly(ε‐caprolactone)](PS‐PEO‐PCL) with different molecular weight was synthesized by combination of the “living” anionic polymerization with the ring‐opening polymerization (ROP) using macro‐initiator strategy. Firstly, the “living” poly(styryl)lithium (PS^?Li⁺) species were capped by 1‐ethoxyethyl glycidyl ether(EEGE) quantitatively and the PS‐EEGE with an active and an ethoxyethyl‐protected hydroxyl group at the same end was obtained. Then, using PS‐EEGE and diphenylmethylpotassium (DPMK) as coinitiator, the diblock copolymers of (PS‐b‐PEO)_p with the ethoxyethyl‐protected hydroxyl group at the junction point were achieved by the ROP of EO and the subsequent termination with bromoethane. The diblock copolymers of (PS‐b‐PEO)_d with the active hydroxyl group at the junction point were recovered via the cleavage of ethoxyethyl group on (PS‐b‐PEO)_p by acidolysis and saponification successively. Finally, the copolymers (PS‐b‐PEO)_d served as the macro‐initiator for ROP of ε‐CL in the presence of tin(II)‐bis(2‐ethylhexanoate)(Sn(Oct)₂) and the star(PS‐PEO‐PCL) terpolymers were obtained. The target terpolymers and the intermediates were well characterized by ¹H‐NMR, MALDI‐TOF MS, FTIR, and SEC. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1136–1150, 2008