Recent advances in the solution self‐assembly of amphiphilic “rod‐coil” copolymers

Solution self‐assembly of amphiphilic “rod‐coil” copolymers, especially linear block copolymers and graft copolymers (also referred to as polymer brushes), has attracted considerable interest, as replacing one of the blocks of a coil‐coil copolymer with a rigid segment results in distinct self‐assembly features compared with those of the coil‐coil copolymer. The unique interplay between microphase separation of the rod and coil blocks with great geometric disparities can lead to the formation of unusual morphologies that are distinctly different from those known for coil‐coil copolymers. This review presents the recent achievements in the controlled self‐assembly of rod‐coil linear block copolymers and graft copolymers in solution, focusing on copolymer systems containing conjugated polymers, liquid crystalline polymers, polypeptides, and polyisocyanates as the rod segments. The discussions concentrate on the principle of controlling over the morphology of rod‐coil copolymer assemblies, as well as their distinctive optical and optoelectronic properties or biocompatibility and stimuli‐responsiveness, which afford the assemblies great potential as functional materials particularly for optical, optoelectronic and biological applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1459–1477     

One‐step synthesis of a thienylenepyridazinylenethienylene‐based coil‐rod‐coil copolymer with enhanced emission and improved fluorescence stability

A new coil‐rod‐coil copolymer is synthesized via Sonogashira coupling using one‐step methodology. The copolymer PEG‐OEPETPT‐PEG constitutes of poly(ethylene glycol) (PEG) as the coil block, and oligo[p‐(ethynylenephenyleneethynylene)‐alt‐(thienylenepyridazinylenethienylene)] (OEPETPT) as the rod segment. The conjugated polymer PEPETPT with the same conjugated building blocks is also synthesized for comparison. The structures of both polymers are confirmed by NMR, combined with other characterizations. PEG‐OEPETPT‐PEG has a 12 nm blue‐shift in the emission maximum compared with that of PEPETPT, and a higher quantum yield of fluorescence in THF. PEG‐OEPETPTE‐PEG tolerates up to 20% water content in H₂O/THF mixed solvent without significantly changing the emission wavelength and intensity, while the fluorescence of PEPETPT is dramatically quenched by a very small quantity of water. Further photophysical studies about these two polymers indicate that the introduction of PEG coils onto the conjugated block retards the water‐induced‐aggregation and therefore improves the fluorescence stability of PEG‐OEPETPT‐PEG. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Oligo(p‐phenyleneethynylene)‐based coil–rod–coil triblock copolymer: Synthesis and controlled self‐organization in solution

The self‐assembling ability of block copolymers offers an attractive strategy for the organization of π‐conjugated polymers. This article reports the synthesis of a coil–rod–coil triblock copolymer consisting of oligo(p‐phenyleneethynylene) as the rodlike segment and polystyrene as the coil‐like segment. The chemical structure of the afforded triblock copolymer has been fully characterized by various spectroscopic techniques such as NMR, Raman, gel permeation chromatography, differential scanning calorimetry, ultraviolet–visible, and fluorescence spectroscopy. The small‐angle neutron scattering and photophysical measurements indicate that this triblock copolymer exhibits unique solvatochromatic behaviors through the interplay of aggregation‐induced π–π stacking and planarization of the conjugated backbone. Supramolecular gel nanostructures have been produced via the controlled assembly of the polymer into H‐aggregates. It has been demonstrated that the use of the solvent composition to influence chain conformations and thus to manipulate the packing of the conjugated polymer blocks is important for achieving control in the assembly of conducting polymers and associated optical characteristics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 6007–6019, 2005     

Spontaneous formation of narrowly‐distributed self‐assembly from polyamidoamine dendron‐poly(L‐lysine) block copolymers through helix‐coil transition of poly(L‐lysine) block

The self‐assembly of head‐tail type block copolymers composed of polyamidoamine dendron head block and poly(L ‐lysine) (PLL) tail block was studied using a light scattering technique and transmission electron microscopy. A PLL tail block in a head‐tail type block copolymer exhibits a coil‐to‐helix transition as a result of the change in solvent quality from water to methanol. When the PLL tail block takes a helical conformation in high methanol content, the resulting head‐tail type block copolymer has a defined three‐dimensional structure like that of a protein molecule. Self‐assemblies of such block copolymers having a totally fixed molecular shape spontaneously form polymersome‐like self‐assemblies with an extremely narrow size distribution through converging to a thermodynamically stable assembling state. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1217–1223, 2009     

Synthesis and self‐assembly in water of coil‐rod‐coil amphiphilic block copolymers with central π‐conjugated sequence

The purpose of this study is to correlate the nano‐organization in water of coil‐rod‐coil amphiphilic block copolymers constituted of a conjugated segment to their optoelectronic properties. The ABA block copolymer structures, easily achieved via coupling reactions, are based on conjugated rod of dihexylfluorene and 3,4‐ethylenedioxythiophene units linked to two flexible poly(ethylene oxide) or poly[(ethylene oxide)‐ran‐(propylene oxide)] chains. These well‐defined copolymers exhibited a range of specific morphologies in water, a good solvent of coil blocks and a bad solvent of the conjugated rod. Particularly, vesicles and micelles with spherical, cylindrical, or elongated shape were noticed. Correlations were attempted to be established between the weight percent of the conjugated sequence contained in the copolymers, the morphology of the nanostructures obtained by self‐assembly in solution and the resulting optical properties. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4602–4616, 2008     

Effects of polydepsipeptide side‐chain groups on the temperature sensitivity of triblock copolymers composed of polydepsipeptides and poly(ethylene glycol)

To develop new types of biodegradable polymers possessing predictable responses to changes in temperature, ABA‐type and BAB‐type triblock copolymers composed of various polydepsipeptides (PDP) and poly(ethylene glycol) (PEG) (PDP‐PEG‐PDP and PEG‐PDP‐PEG) were synthesized. The specific focus of this study was on the effect of the different side‐chain groups of various amino acids on the temperature‐responsive behavior of the triblock copolymers. An ABA‐type triblock copolymer containing the less hydrophobic glycine (PGG‐PEG‐PGG) did not exhibit any temperature‐responsive behavior; however, ABA‐type triblock copolymers containing the hydrophobic α‐amino acids, L ‐leucine and L ‐phenylalanine (PGL‐PEG‐PGL or PGF‐PEG‐PGF), did exhibit temperature‐responsive behavior. The cloud point of PGF‐PEG‐PGF was 10 °C lower than that of PGL‐PEG‐PGL. It can be possible to control temperature‐sensitivity by changing not only PDP segment length but also kind of α‐amino acid in PDP segment. Moreover, BAB‐type triblock copolymer containing L ‐leucine (PEG‐PGL‐PEG) showed temperature‐responsive sol‐gel transition. Because polydepsipeptides are biodegradable polymers, the information obtained in this study is useful to design biodegradable injectable polymers having controllable temperature‐sensitivity for biomedical use.© 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3892–3903, 2009     

Self‐assembly of di‐ and triblock PEG‐pentavaline amphiphiles

Nanoparticles formed from amphiphilic block copolymers can be used as drug delivery vehicles for hydrophilic therapeutics. Poly(ethylene glycol) (PEG)‐peptide copolymers were investigated for their self‐assembling properties and as consequent potential delivery systems. Mono‐ and dihydroxy PEGs were functionalized with a pentavaline sequence bearing Fmoc end groups. The molecular weight of the PEG component was varied to evaluate copolymer size and block number. These di‐ and tri‐block copolymers readily self‐assemble in aqueous solution with critical aggregation concentrations (CACs) of 0.46–16.29 μM. At concentrations above the CAC, copolymer solutions form spherical assemblies. Dynamic light scattering studies indicate these aggregates have a broad size distribution, with average diameters between 33 and 127 nm. The copolymers are comprised β‐conformations that are stable up to 80 °C, as observed by circular dichroism. This peptide secondary structure is retained in solutions up to 50% MeOH as well. The triblock copolymers proved to be the most stable, with copolymers synthesized from 10 kDa PEG having the most stable particles. Loading of carboxyfluorescein at 2–5 mol % shows that these copolymers have the potential to encapsulate hydrophilic drugs for delivery applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis of poly(2‐vinyl pyridine)‐b‐poly(n‐hexyl isocyanate) amphiphilic coil‐rod block copolymer by anionic polymerization

A well‐defined amphiphilic coil‐rod block copolymer, poly(2‐vinyl pyridine)‐b‐poly(n‐hexyl isocyanate) (P2VP‐b‐PHIC), was synthesized with quantitative yields by anionic polymerization. A low reactive one‐directional initiator, potassium diphenyl methane (DPM‐K), was very effective in polymerizing 2‐vinyl pyridine (2VP) without side reactions, leading to perfect control over molecular weight and molecular weight distribution over a broad range of initiator and monomer concentration. Copolymerization of 2VP with n‐hexyl isocyanate (HIC) was carried out in the presence of sodium tetraphenyl borate (NaBPh₄) to prevent backbiting reactions during isocyanate polymerization. Terminating the living end with a suitable end‐capping agent resulted in a P2VP‐b‐PHIC coil‐rod block copolymer with controlled molecular weight and narrow molecular weight distribution. Cast film from a chloroform solution of P2VP‐b‐PHIC displayed microphase separation, characteristic of coil‐rod block copolymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 607–615, 2005     

Synthesis and optical properties of green‐light‐emitting copolymers containing side‐chain oxadiazole units

Atom transfer radical polymerization was used to prepare well‐defined vinyl polyoxadiazole homomacromonomers with a properly modified α‐dicarboxylic acid methyl ester as the initiator. Macromonomers of various molecular weights with narrow polydispersities in some cases were obtained, as proved by gel permeation chromatography (GPC). The structures of the obtained macromonomers were then identified with ¹H NMR spectroscopy. These macromonomers were subsequently copolymerized with a dihydroxy anthracene based monomer by a polycondensation technique, and this resulted in polymacromonomers. Coil–rod–coil copolymers containing side‐chain anthracene and oxadiazole units were also synthesized by atom transfer radical polymerization. The resulting copolymers combined an anthracene derivative as the rigid block with a random copolymer of the desired anthracene‐ and/or oxadiazole‐based monomers as the flexible block. These copolymers were primarily characterized with GPC and ¹H NMR techniques. Additionally, the optical properties of all these copolymers were investigated in detail, and they suggested energy transfer from the oxadiazole to the anthracene chromophores, which became much more efficient in the solid state. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1049–1061, 2005     

Synthesis and characterization of a poly(GMA)‐graft‐poly(Z‐L‐lysine) graft copolymer with a rod‐like structure

This study applied the macromonomers and glycidyl methacrylate (GMA) to synthesize a series of the graft copolymers, poly(GMA)‐graft‐poly(Z‐L ‐lysine), and investigated the conformation of the graft copolymer. The graft copolymers were synthesized with different GMA monomer ratios (28 to 89%) and different degrees of polymerization (DP) (8 to 15) of the poly(Z‐L ‐lysine) side chain to analyze secondary structure relationships. Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and both wide angle and small angle X‐ray scattering spectroscopy (WAXS, SAXS) were used to investigate the relationship between the microstructure and conformation of the graft copolymers and the different monomer ratios and side chain DP. In AFM images, n8‐G89 (the graft copolymer containing 89% GMA units and the macromonomer DP is 8) showed tiny and uniform rod‐like structures, and n14‐G43 (the graft copolymer containing 43% GMA units and the macromonomer DP is 14) showed uniform rod‐like structures. FTIR spectra of the graft copolymers showed that the variations of α‐helix and β‐sheet secondary structures in the graft copolymers relate to the monomer ratios of the graft copolymers. However, the X‐ray scattering patterns indicated that the graft copolymer conformations were mainly dependent on the poly(Z‐L ‐lysine) side chain length, and these results were completely in accordance with the AFM images. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4655–4669, 2009     

Tailoring of block copolymers based on the stoichiometric control of the end‐functionality of telechelic oligomers and the utilization of large‐scale fractionation by phase fluctuation chromatography: A synthetic strategy for the preparation of end‐functionalized poly(L‐lactide)‐block‐poly(oxyethylene)

An AB diblock copolymer of poly(L ‐lactide) (PLLA) and poly(oxyethylene) (PEG) with a cinnamate terminal in the PEG block was prepared by the copolymerization of L ‐lactide and partially end‐modified PEG followed by fractionation. The first step was the terminal modification of PEG with cinnamoyl chloride (CC), in which the degree of cinnamoylation of the hydroxyl terminals of PEG was roughly controlled by the feed ratio of both reactants. The resultant PEG cinnamate was subjected to copolymerization with L ‐lactide to produce a mixture of unreacted PEG dicinnamate (C‐PEG‐C), the diblock copolymer (PLLA‐PEG‐C), and the triblock copolymer (PLLA‐PEG‐PLLA) corresponding to the three components of the PEG cinnamate. This mixture was separated by phase fluctuation chromatography (PFC) to obtain PLLA‐PEG‐C in sufficient purity. This process, involving the stoichiometric control of the terminal reaction of telechelic oligomers and the utilization of PFC for fractionation, can be an efficient method for synthesizing end‐functionalized diblock copolymers from readily available telechelic oligomers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2405–2414, 2000     

Facile syntheses,morphologies, and optical absorptions of P3HT coil‐rod‐coil triblock copolymers

Here we report syntheses, photophysical properties, and morphologies of a series of coil‐rod‐coil ABA triblock copolymers containing highly regioregular poly(3‐hexylthiophene) (P3HT) as the central rod block. A new methodology, based on the coupling reaction between living polymeric anions [polystyrene, polyisoprene, and poly(methyl methacrylate)] and aldehyde terminated P3HT, was successfully developed to synthesize the triblock copolymers with low polydispersities. This coupling reaction was effective for building blocks with a variety of molecular weights; therefore, a good variation in compositions of the triblock copolymers could be feasibly achieved. The non‐P3HT coil segments and the solvents were found to exhibit noticeable effects on morphologies of the spin‐coated thin films. Attachment of the coil segments to P3HT did not change the optical absorption of the P3HT segment as the block copolymers were dissolved in solution regardless the chemical structure and the molecular weight of the coil segment. Interestingly, different UV–vis absorption behaviors were observed for the spin‐coated thin films of the block copolymers, which closely related to their morphologies. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3311–3322, 2010     

Morphology control and inducing a curvature on the domain interface by increasing the steric bulk of polymethacrylate in POSS‐containing diblock copolymers

Herein, a novel rod‐coil type polyhedral oligomeric silsesquioxane (POSS)‐containing diblock copolymer was designed to enable the self‐assembly of hexagonally packed cylinders of the POSS‐containing domain in a poly(n‐butyl methacrylate) (PnBMA) matrix. When POSS‐containing diblock copolymers were synthesized with polyisoprene or poly(methyl methacrylate), cylindrical structures could not be obtained as POSS‐containing polymers form stretched rigid rods. This makes the formation of cylindrical structures with the POSS‐containing domain entropically unfavorable. Therefore, to obtain the cylindrical structures, we constructed a novel diblock copolymer using PnBMA to increase the steric bulk and segment volume of the flexible coil. Steric crowding of the butyl groups reduces the entropic free stretching energy of the PnBMA chains, which in turn encourages the formation of a POSS‐containing hexagonally packed cylindrical structure within the PnBMA matrix as the system minimizes the total free energy of the thermodynamically stable nanostructure. Small angle X‐ray scattering and transmission electron microscopy analyses indicated that cylinders of the POSS domain had formed. Oxygen plasma etching was then used on the thin film to selectively remove the PnBMA domain to yield line and space structures with a high degree of long‐range order and a 14 nm feature size. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2234–2242     

Influence of the polymer structure over self‐assembly and thermo‐responsive properties: The case of PEG‐b‐PCL grafted copolymers via a combination of RAFT and ROP

During the last years, the field of drug delivery has experienced a growing interest toward the so‐called thermo‐responsive polymers: synthetic materials that, due to the specific hydrophilic–lipophilic balance of their repeating units, exhibit a lower critical solution temperature (LCST) in water associated to a characteristic coil–globule transition. In this work, thermo‐responsive amphiphilic block copolymers are synthesized via reversible addition‐fragmentation transfer (RAFT) polymerization starting from thermo‐responsive monomers and a hydrophobic biodegradable macromonomer, oligo(caprolactone)methacrylate (CL₃MA), produced via ring opening polymerization (ROP). The obtained copolymers exhibit an interesting self‐assembly behavior leading to nanoparticles (NPs) as long as temperature is kept below the LCST. Otherwise, once this value is overcome, the destabilization of the NPs causes the formation of hydrophobic superstructures that enhance the release of an entrapped lipophilic drug. This characteristic behavior has been systematically studied and related to the copolymer structure. In particular, the self‐assembly behavior as well as temperature‐triggered NP destabilization have been related to the relative length of the two blocks constituting the copolymers and to their hydrophilic–lipophilic balance (HLB). Finally, the efficacy of the thermo‐responsive triggered drug release has been tested in the case of Paclitaxel (PTX). © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2919–2931     

Chemical synthesis and characterization of poly(aniline‐co‐ethyl 3‐aminobenzoate) copolymers

Copolymers of aniline and ethyl 3‐aminobenzoate (3EAB) were synthesized by chemical polymerization in several mole ratios of aniline to functionalized aniline, and their physicochemical properties were compared to those of poly(aniline‐co‐3‐aminobenzoic acid) (3ABAPANI) copolymers. The copolymers were characterized with UV–vis, FTIR, Raman, SEM, EPR, and solid‐state NMR spectroscopy, elemental analysis, and conductivity measurements. The influence of the carboxylic acid and ester group ring substituents on the copolymers was investigated. The spectroscopic studies confirmed incorporation of 3ABA or 3EAB units in the copolymers and hence the presence of C?O group in the copolymer chains. The conductivity and EPR signals both decreased with increasing 3EAB content of the copolymers emeraldine salt (ES) form. The conductivity of the ES form of 3ABAPANI was found to be high (1.4 × 10^?1 S cm^?1) compared with the conductivity (10^?2–10^?3 S cm^?1) of 3EABPANI (ES) copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1339–1347, 2010     

Synthesis of a novel liquid crystal rod–coil star block copolymer consisting of poly(methyl methacrylate) and poly{2,5‐bis[(4‐methoxy‐phenyl)oxycarbonyl] styrene} via atom transfer radical polymerization

A bromine capped star‐shaped poly(methyl methacrylate) (S‐PMMA‐Br) was synthesized with CuBr/sparteine/PT‐Br as a catalyst and initiator to polymerize methyl methacrylate (MMA) according to atom transfer radical polymerization (ATRP). Then, with S‐PMMA‐Br as a macroinitiator, a series of new liquid crystal rod–coil star block copolymers with different molecular weights and low polydispersity were obtained by this method. The block architecture {coil‐conformation of the MMA segment and rigid‐rod conformation of 2,5‐bis[(4‐methoxyphenyl)oxycarbonyl] styrene segment} of the four‐armed rod–coil star block copolymers were characterized by ¹H NMR. The liquid‐crystalline behavior of these copolymers was studied by differential scanning calorimetry and polarized optical microscopy. We found that the liquid‐crystalline behavior depends on the molecular weight of the rigid segment; only the four‐armed rod–coil star block copolymers with each arm's M_n,_GPC of the rigid block beyond 0.91 × 10⁴ g/mol could form liquid‐crystalline phases above the glass‐transition temperature of the rigid block. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 733–741, 2005     

Comparative study of 2‐amino and 3‐aminobenzoic acid copolymerization with aniline synthesis and copolymer properties

Polyanilines soluble in an aqueous basic medium were synthesised by copolymerization of aniline (ANI) with both 2 and 3‐aminobenzoic acids (ABA). Different composition copolymers were prepared by varying the ANI/ABA feed ratio. Poly(aniline‐co‐2‐aminobenzoic acid) (PANI2ABA) and poly(aniline‐co‐3‐aminobenzoic acid) (PANI3ABA) displayed differences in their properties, such as specific charge and fluorescence behavior because the reactivity of 2‐aminobenzoic (2ABA) and 3‐aminobenzoic (3ABA) acids are very different. The new materials were characterized by X‐ray photoelectron, Fourier transform infrared, and Raman spectroscopies. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5587–5599, 2004     

Copolymers and two-layered composites of poly(<Emphasis Type="Italic">o</Emphasis>-aminophenol) and polyaniline

Electroactive conducting copolymers of aniline (ANI) and o-aminophenol (OAP) and two-layered poly(o-aminophenol) (POAP)/polyaniline (PANI) composites were prepared in aqueous acidic solution by electrode potential cycling. Copolymerization was carried out at different feed concentrations of OAP and ANI on a gold electrode. A strong inhibition of electropolymerization was found at a high molar fraction of OAP in the feed. The copolymers showed good adherence on the electrode surface and gave a redox response up to pH=10.0. Two transitions were observed in the in situ conductivities of the copolymers (as with PANI), but the conductivities were lower by 2.5–3 orders of magnitude as compared to PANI. Electrosynthesis of PANI on POAP modified electrodes showed copolymer formation after reaction initiation and finally formation of a PANI layer at the copolymer/solution interface. The ‘memory effect’ of the bilayer structures of both polymers was discussed in terms of protonation/deprotonation and anion consumption taking place during redox processes of both polymers.     

Preparation of densely grafted poly(aniline‐2‐sulfonic acid‐co‐aniline)s as novel water‐soluble conducting copolymers

Various densely grafted polymers containing poly(aniline‐2‐sulfonic acid‐co‐aniline)s as side chains and polystyrene as the backbone were prepared. A styryl‐substituted aniline macromonomer, 4‐(4‐vinylbenzoxyl)(N‐tert‐butoxycarbonyl)phenylamine (4‐VBPA‐^tBOC), was first prepared by the reaction of 4‐aminophenol with the amino‐protecting moiety di‐tert‐butoxyldicarbonate, and this was followed by substitution with 4‐vinylbenzyl chloride. 4‐VBPA‐^tBOC thus obtained was homopolymerized with azobisisobutyronitrile as an initiator, and this was followed by deprotection with trifluoroacetic acid to generate poly[4‐(4‐vinylbenzoxyl)phenylamine] (PVBPA) with pendent amine moieties. Second, the copolymerization of aniline‐2‐sulfonic acid and aniline was carried out in the presence of PVBPA to generate densely grafted poly(aniline‐2‐sulfonic acid‐co‐aniline). Through the variation of the molar feed ratio of aniline‐2‐sulfonic acid to aniline, various densely grafted copolymers were generated with different aniline‐2‐sulfonic acid/aniline composition ratios along the side chains. The copolymers prepared with molar feed ratios greater than 1/2 were water‐soluble and had conductivities comparable to those of the linear copolymers. Furthermore, these copolymers could self‐dope in water through intermolecular or intramolecular interactions between the sulfonic acid moieties and imine nitrogens, and this generated large aggregates. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1090–1099, 2005     

Facile synthesis of conjugated rod‐coil block copolymers

A facile synthetic approach of conjugated rod‐coil block copolymers with poly(para‐phenylene) as the rod block and polystyrene or polyethylene glycol as the coil block was developed. The block copolymers were synthesized through a TEMPO‐mediated radical polymerization of 3,5‐cyclohexadiene‐1,2‐diol‐derived monomers (diacetate, dibenzonate, and dicarbonate), followed by thermal aromatization of the polymer precursor. The living character of the polymerization and the structure of the copolymers were studied by NMR, GPC, TGA, and UV–vis spectroscopy. The average conjugation lengths of the copolymers were calculated according to their maxima in UV–vis spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 800–808, 2007