Synthesis of conjugated polymers with broad absorption bands and photovoltaic properties as bulk heterojuction solar cells

Two new broad absorbing alternating copolymers, poly[1-(2,6-diisopropylphenyl)-2,5-bis(2-thienyl)pyrrole-alt-4,7-bis(3-octyl-2-thienyl)benzothiadiazole] (PTPTTBT-P1) and poly[1-(p-octylphenyl)-2,5-bis(2-thienyl)pyrrole-alt-4,7-bis(3-octyl-2-thienyl)benzothiadiazole] (PTPTTBT-P2), were prepared via Suzuki polycondensation with high yields. The two polymers were found to show characteristic absorption in the visible region of the solar spectrum. Interestingly the absorption of PTPTTBT-P1 was found to cover the visible region from 350 to 650 nm with the broad and flat absorption maximum from 440 to 510 nm in film and the absorption of PTPTTBT-P2 was found to cover the visible region from 350 to 950 nm with the relatively distinct absorption maxima at 425 and 522 nm and very weak absorption maximum at 832 nm in film. The electrochemical band gaps of the polymers were calculated to be 1.88 eV and 1.87 eV, respectively, while the optical band gaps of the polymers were calculated to be 1.94 eV and 1.87 eV, respectively. The photovoltaic properties of polymers were investigated with bulk heterojunction (BHJ) solar cells fabricated in ITO/PEDOT:PSS/polymer:PC₇₀BM(1:5 wt%)/TiOx/Al configurations. The maximum power conversion efficiency (PCE) of the solar cell composed of PTPTTBT-P1:PC₇₀BM as an active layer was 1.57% with current density (J_sc) of 8.17 mA/cm², open circuit voltage (V_oc) of 0.52 V and fill factor (FF) of 36%.     

Optically active methacrylic copolymers with side-chain azoaromatic and 9-phenylcarbazole moieties

The synthesis and structural characterization of optically active copolymers such as poly[(S)-(+)-MCPP-co-(S)-MAP-N] and poly[(S)-(+)-MCPP-co-(S)-MAP-C] has been performed in order to obtain a multifunctional photonic material for chiroptical switches and for optical storage applications.The observed chiroptical properties suggest the presence of ordered chiral conformations at least for the chain segments of the macromolecules. Spectroscopic, thermal and chiroptical characterization of these copolymers demonstrate the occurrence of significant electronic interactions between the carbazole chromophores and the azobenzene moieties. The photoinduction of birefringence of copolymer films has been investigated in order to evaluate their behavior as a material for optical data storage. Surface-relief gratings (SRG) have also been inscribed on the material.The results are interpreted in terms of copolymer composition, cooperative behavior and conformational stiffness of the chromophoric co-units.     

Synthesis and optoelectronic properties of luminescent copolyfluorenes slightly doped with thiophene chromophore

This paper describes the synthesis of new copolyfluorenes (P05-P5) slightly doped with 2,5-bis(2-phenyl-2-cyanovinyl)thiophene (GM, <3.4 mol%) and their application in electroluminescent (EL) devices. In film state, EL spectra of the copolyfluorenes are very different from photoluminescence (PL) spectra, which have been ascribed to charge trapping in GM and energy transfer from fluorene segments to GM chromophores. The maximum brightness and current efficiency of EL device from P05 (5230 cd/m², 0.65 cd/A) are significantly enhanced when compared with those from poly(9,9-dihexylfluorene) (PF) (1310 cd/m², 0.18 cd/A). The EL device using blend of P5 and PF (w/w = 10/1) as emitting layer exhibits near-white emission with CIE coordinate being (0.26, 0.32). The results demonstrate that the copolyfluorenes slightly doped with GM chromophore are promising emitting materials for optoelectronic devices.     

Redox-active conducting polymers incorporating ferrocenes. Preparation, characterization and bio-sensing properties of ferrocenylpropyl and -butyl polypyrroles

The multi-step synthesis of the novel ferrocene-substituted pyrrole monomers, N-(3-ferrocenylpropyl)pyrrole (1), and 3-(4-ferrocenylbutyl)pyrrole (2), have been studied and optimized. A single crystal X-ray structure analysis has been performed on the synthetic intermediate 3-(4-ferrocenylbutyl)-N-(triisopropylsilyl)pyrrole. Monomers 1 and 2 can be electropolymerized to form the homopolymer, poly-2, and the copolymers, pyrrole-co-1 and pyrrole-co-2. The polymers have been characterized using cyclic voltammetry, UV-visible spectroscopy, scanning electron microscopy (SEM) and four-point probe conductivity measurements. The use of pyrrole-co-1 coatings for quantitative sensing and determination of the redox-active enzyme cytochrome C in solution has been demonstrated.     

Copolymers containing pendant styryltriphenylamine and carbazole groups: Synthesis, optical, electrochemical properties and its blend with Ir(ppy)3

A series of vinyl copolymers (PVKST12-PVKST91) and homoploymer PVST containing pendant hole-transporting 4-(4-oxystyryl)triphenylamine (12-100 mol%) and carbazole chromophores were synthesized by radical copolymerization and employed as host for Ir(ppy)₃ phosphor to tune emission color. They were characterized using the ¹H NMR, FT-IR, absorption and photoluminescence spectra, elemental analysis, GPC, cyclic voltammetric and thermal analysis (DSC, TGA). Their weight-average molecular weights (M_w) and decomposition temperatures (T_d) were 1.46-5.68 × 10⁴ and 356-399 °C, respectively. The HOMO levels of PVKST12-PVKST91 and PVST, estimated from the onset oxidation potentials in cyclic voltammograms, were −5.40 to −5.14 eV, which are much higher than −5.8 eV of the conventional host poly(9-vinylcarbazole) (PVK) owing to high hole-affinity of the 4-(4-oxystyryl)triphenylamine groups. Therefore, copolymers PVKST are effective in reducing hole-injection barrier between the PEDOT:PSS and emitting layer. Electroluminescent devices [ITO/PEDOT:PSS/PVKST:Ir(ppy)₃:PBD/BCP/Ca/Al] using the hole-transporting PVKST as host were fabricated to tune the emission color. Their EL spectra showed a major emission at 515 nm and a minor peak at 435 nm attributed to Ir(ppy)₃ and 4-(4-oxystyryl)triphenylamine, respectively. The C.I.E. 1931 coordinates shift from (0.29, 0.61) for PVK to (0.33, 0.42) for PVST with an increase in 4-(4-oxystyryl)triphenylamine content.     

Helical conformation of the copolymers of l-proline derivatives based propargylether and chiral N-propargylamide

The novel acetylene monomers, l-proline derivatives based propargylethers PR (PA, PC, and PL) were synthesized by alkylation of Boc-hydroxyproline with propargyl bromide and acylation of achiral amine. The homopolymers of the novel acetylene monomer exist in no regulated higher order structure in solvents because of the lack of hydrogen bond and the unique ring structure in the pendant. Consequently, the copolymerization of l-proline-derived chiral propargylether PR with the l-alanine-derived N-propargylamide (LA) was formed and the chiroptical properties of the formed copolymers were examined. We conclude that (1) N-H of the amide group at 2-position in proline play an important role in the formation of helical conformation of poly(LA₈₈-co-PR₁₂); (2) improving the amount of PC of poly(LA-co-PC) changes the conformation of the copolymer in CHCl₃ and perturbs the leadership of LA; (3) the conformation of poly(LA₇₅-co-PC₂₅) remarkably changes with changing temperature and PC obtains the leadership in the competition on the conformation of poly(LA₇₅-co-PC₂₅) in CHCl₃ with the improvement of temperature.     

Enhancement of electroluminescence properties of red diketopyrrolopyrrole-doped copolymers by oxadiazole and carbazole units as pendants

Two novel diketopyrrolopyrrole (DPP)-based copolymers P1-2 were prepared by doping red emitting DPP monomer (1 mol%) into benzothiadiazole, alkoxybenzene and 9,9-dialkylfluorene-based copolymers through base-free Suzuki polymerization. P1 contained the pendants of electron-transport oxadiazole and hole-transport carbazole, but P2 did not contain them. P1 had higher glass transition temperature than P2. The electroluminescence (EL) devices of P1 and P2 (ITO/PEDOT:PSS/polymer/CsF/Al) exhibited red emission with external quantum efficiency of 0.63% and 0.18%, and with brightness of 2681 and 885 cd/m², respectively. The results show that the EL properties of P1 are much better than that of P2 due to the introduction of oxadiazole and carbazole as the pendants. The pendants could restrain aggregation which might induce fluorescence quenching and are of benefit to keep high charge mobility. The efficient energy transfer existed among the pendants, polymer backbone and DPP unit. These factors should be responsible for the higher EL performance of P1.     

Synthesis and photovoltaic properties of D-π-A copolymers based on thieno[3,2-b]thiophene bridge unit

Three D-π-A copolymers containing thieno[3,2-b]thiophene (TT) bridge and BDT, carbazole, fluorene as D units and benzothiadiazole as A unit were synthesized and characterized. These copolymers of PBDT-tt-BT, PC-tt-BT and PF-tt-BT exhibited enough high thermal stabilites and good solubilites in chloroform and dichlorobenzene. Among the copolymers, with the increase of the electron-donating abilities of the D units from fluorene to carbazole further to BDT, the absorption spectra of PF-tt-BT shows blue shift and that of PBDT-tt-BT shows red shift comparing to that of PC-tt-BT in their solutions and films. Meanwhile, by electrochemical cyclic voltammetry measurements we found the HOMO levels vary in the same trench according to their electron-donating abilities. Under the illumination of AM 1.5G, 100 mW/cm², power conversion efficiency (PCE) of the PSCs based on these copolymers as donors and PC₇₀BM as acceptor were measured and PBDT-tt-BT shows a higher efficiency of 4.91% than PC-tt-BT and PF-tt-BT based devices mostly due to its higher hole mobility and broader absorption range. These results indicate that PBDT-tt-BT is a promising photovoltaic polymer donor material for efficient PSCs.     

Structural determination of stretched helix and contracted helix having yellow and red colors of poly(2-ethynylnaphthalene) prepared with a [Rh(norbornadiene)Cl]2-triethylamine catalyst

The Rh-catalyzed polymerization of 2-ethynylnaphthalene (2EN) using ethanol or toluene solvents afforded helical poly(2-ethynylnaphthalene)s (P2EN)s, i.e., yellow-colored P2EN(Y) and red-colored P2EN(R) in good yields, respectively. The diffuse reflective UV–vis (DRUV–vis) spectra of P2EN(Y) and P2EN(R) in the solid phase showed broad absorption peaks at 445 nm and 510 nm, respectively. These helical and its crystal structures were investigated using wide angle X-ray scattering (WAXS), resonance laser Raman, and molecular mechanics calculation using MMFF94 force field. Based on these analyses, we found that P2EN(Y) was composed of stretched cis-transoid helices and P2EN(R) was composed of contracted cis-cisoid helices in which form intramolecular π-stacking by ca. 3.4 Å in distance between neighboring naphthyl rings. Furthermore, the contracted helix was energetically more stable than the stretched helix. The P2EN(Y) changed to a red-colored polymer, P2EN(Y-R), by immersion in toluene. This P2EN(Y-R) completely coincides with the P2EN(R) in its crystal structure and DRUV–vis spectrum.     

New host copolymers containing pendant triphenylamine and carbazole for efficient green phosphorescent OLEDs

A series of vinyl copolymers (P1-P6) containing pendant hole-transporting triphenylamine (11-88 mol%) and carbazole chromophores were synthesized by radical copolymerization to investigate the influence of triphenylamine groups upon optoelectronic properties. The copolymers were readily soluble in common organic solvents and their weight-average molecular weights (M_ws) were between 1.41 × 10⁴ and 2.24 × 10⁴. They exhibited moderate thermal stability with T_d = 402-432 °C at 5% weight loss. The emission spectra (both PL and EL) of the blends [P1-P6 with 4 wt% Ir(ppy)₃] showed dominant green emission (517 nm) attributed to Ir(ppy)₃ due to efficient energy transfer from P1-P6 to Ir(ppy)₃. The HOMO levels of P1-P6, estimated from onset oxidation potentials in cyclic voltammeter, were −5.42 to −5.18 eV, which are much higher than −5.8 eV of conventional poly(9-vinylcarbazole) (PVK) host owing to high hole-affinity of the triphenylamine groups. The optoelectronic performances of phosphorescent EL devices, using P1-P6 as hosts and Ir(ppy)₃ as dopant (ITO/PEDOT:PSS/P1-P6:Ir(ppy)₃ (4 wt%):PBD (40 wt%)/BCP/Ca/Al), were greatly improved relative to that of PVK. The best performance was obtained with P4 device, in which the maximum luminance and luminance efficiency were 11?501 cd/m² and 10.6 cd/A, respectively.     

Polymerization of cysteine functionalized thiophenes

Different synthetic pathways leading to polythiophenes (PTs) containing units derived from methyl N-(tert-butoxycarbonyl)-S-3-thienyl-l-cysteinate (1) and methyl N-(tert-butoxycarbonyl)-S-(2-thien-3-ylethyl)-l-cysteinate (2) were investigated. The oxidative coupling with FeCl₃ applied to N-deprotected monomer 1 generates a chemically fleeting PT, whereas when applied to N-deprotected monomer 2 generates a mixture of oligomers. Two co-polymers bearing cysteine moieties, poly{[methyl N-(tert-butoxycarbonyl)-S-3-thienyl-l-cysteinate]-co-thiophene} (co-PT1) and poly{[methyl N-(tert-butoxycarbonyl)-S-(2-thien-3-ylethyl)-l-cysteinate]-co-thiophene} (co-PT2), were eventually synthesized through Stille coupling of 2,5-bis(trimethylstannyl)thiophene and 2,5-dibromo derivative of compound 1 and through the post-functionalization with protected cysteine of a tosylate co-polymer, poly{[2-(3-thienyl)ethyl 4-methylbenzenesulfonate]-co-thiophene} (co-PTTs). UV-vis, CD, NMR and GPC analyses evidenced that these polymers are able to form chiral self-assembling structures, due to the formation of a hydrogen bond network and to π-stacks, not only in the solid state but also in solution.     

Synthesis, X-ray crystal structure and optical properties of novel 2,5-diaryl-1,3,4-oxadiazole derivatives containing substituted pyrazolo[1,5-a]pyridine units

A series of pyrazolo[1,5-a]pyridine-containing 2,5-diaryl-1,3,4-oxadiazole derivatives were synthesized and their structures were characterized by IR, ¹H NMR and HRMS spectra. The crystal structure of 3a was determined using single crystal X-ray crystallography. Its spatial structure was found to be monoclinic, and all aromatic rings were approximately coplanar, which allowed conjugation. The absorption results showed that compounds 1a-f presented their absorption peaks ranging from 264 nm to 290 nm, while compounds 3a-f with a larger conjugation system exhibited red-shifted absorption character (absorption maxima between 283 nm and 303 nm) compared to the corresponding absorption of 1a-f. Fluorescence spectra revealed that these compounds exhibited blue fluorescence (421-444 nm) in dilute solutions and showed quantum yields of fluorescence between 0.32 and 0.83 in dichloromethane.     

Polybinaphthyls incorporating chiral 2,2′-binaphthyl and isoquinoline moieties by Sonogashira reaction

Polymers P-1, P-2, P-3, P-4 and P-5 were synthesized by the polymerization of 5,8-bis(ethynyl)isoquinoline (M-1) with (R)-3,3′-diiodo-2,2′-bisbutoxy-1,1′-binaphthyl ((R)-M-2), (S)-3,3′-diiodo-2,2′-bisbutoxy-1,1′-binaphthyl ((S)-M-2), (R)-6,6′-dibromo-2,2′-bisbutoxy-1,1′-binaphthyl ((R)-M-3), (S)-6,6′-dibromo-2,2′-bisbutoxy-1,1′-binaphthyl ((S)-M-3), and rac-6,6′-dibromo-2,2′-bisbutoxy-1,1′-binaphthyl (M-4) under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and circular dichroism (CD) spectroscopy. CD spectra of polymers P-1 and P-2, P-3 and P-4 are almost identical except that they gave opposite signals at each wavelength. The long wavelength CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure in the repeating unit and the helical backbone in the polymer chain. All five polymers have strong blue-green fluorescence due to the efficient energy migration from the extended π-electronic structure of the repeating unit of the polymers to the chiral binaphthyl core and are expected to provide understanding of structure-property relationships of the chiral conjugated polymers.     

Metallocene-catalyzed synthesis of polyethylenes with side-chain triarylamines: Effects of catalyst structure and triarylamine functionality

The copolymerization of ethylene with 8-triarylamine (TAA) substituted 1-octene monomers (TAA = triphenylamine (M1), N,N-diphenyl-m-tolylamine (M2), N,N-diphenyl-1-naphthylamine (M3)) using various types of group 4 single-site catalytic systems (Cp₂ZrCl₂ (C1), rac-EBIZrCl₂ (C2), rac-SBIZrCl₂ (C3), i-PrCpFluZrCl₂ (C4), Me₂Si(η⁵-C₅Me₄)(η¹-N-^tBu)TiCl₂ (C5)) was investigated to prepare functionalized polyethylene with side-chain TAA groups. The metallocene/methylaluminoxane (MAO) catalytic systems (C1-C4) efficiently lead to the production of high-molecular-weight poly(ethylene-co-M1). While the C4/MAO catalytic system shows the highest comonomer response, the C5/MAO system exhibits the poor compatibility with the M1 comonomer. Copolymerization results of ethylene with M1-M3 using C4/MAO indicate that M1-M3 are well tolerated by both the cationic active species of C4 and MAO cocatalyst, giving rise to the copolymers with high levels of activity and molecular weight. Inspection of the aliphatic region of the ¹³C NMR spectra of the copolymers (P1-P3) having ca. 11 mol% of M1-M3, respectively, reveals the presence of isolated comonomer units with prevailing [EEMEE] monomer sequences in the polymer chain. UV-vis absorption and PL spectra exhibit an apparent low-energy band broadening for P1 and P2 indicative of intrachain aggregate formation. Whereas P2 and P3 undergo completely reversible one-electron oxidation process, P1 shows relatively poor oxidational stability.     

Synthesis, characterization and third-order non-linear optical properties of novel fluorene monomers and their cross-conjugated polymers

We designed and synthesized two novel fluorene monomers of D-A-D (donor-acceptor-donor) type (M1 and M2), and their two corresponding polymers (PM1 and PM2) and a copolymer (CPM). These high molecular weight, film-forming polymers were obtained from metal-free, superacid-catalyzed reactions of the monomers with N-phenylisatin. The cubic NLO response (χ⁽³⁾) for these new compounds, in solid thin films, was measured through the use of third-harmonic generation (THG) Maker-Fringes technique at IR wavelengths given values of the order of 10⁻¹² esu from which, the corresponding second hyperpolarizabilities (γ) were estimated to be of the order of 10⁻³³ esu for monomers and 10⁻³¹ esu for polymers. Second hyperpolarizabilities have also been estimated theoretically at B3LYP/6-31G(d) level of theory in gas phase and related with the electronic structure of the synthesized molecules.     

Radical copolymerization of methyl 2-norbornene-2-carboxylate and 2-phenyl-2-norbornene with styrene, alkyl acrylate, and methyl methacrylate: Facile incorporation of norbornane framework into polymer main chain and its effect on glass transition temperature

Radical copolymerization behavior of methyl 2-norbornene-2-carboxylate 1 and 2-phenyl-2-norbornene 2 was investigated. Radical copolymerization of 1 and 2 with styrene, alkyl acrylate, and methyl methacrylate in a variety of monomer combinations afforded copolymers, whose main chains consisted of norbornane framework. Relative monomer reactivity ratios for the copolymerization of 1 and 2 with n-butyl acrylate (n-BA) were determined by the Fineman-Ross method. Temperature-modulated DSC analysis for poly(1 or 2-co-n-BA)s revealed remarkable T_g-raising effect of incorporation of norbornane framework into the polymer main chain, compared to that effect of styrene repeating unit.     

Synthesis and characterization of new fluorene-acceptor alternating and random copolymers for light-emitting applications

A series of novel light-emitting copolymers consisted of 9,9-dihexylfluorene (F) and different acceptor segments, including quinoxaline (Q), 2,1,3-benzothiadiazole (BT) and thieno[3,4-b]-pyrazine (TP), were synthesized by the palladium-catalyzed Suzuki coupling reaction. Three fluorene-acceptor alternating copolymers (PFQ, PFBT, PFTP) and six F-TP (PFTP0.5-PFTP35) random copolymers were investigated and compared with the parent polyfluorene (PF). The experimental results suggest that the acceptor strength or content significantly affect the electronic and optoelectronic properties. The optical absorption maxima of the PF, PFQ, PFBT, and PFTP are 368, 416, 470, and 578 nm, respectively, which indicates the significance of intramolecular charge transfer. The electrochemical band gap also shows a similar trend. The incorporation of the acceptor into the PF lowers the LUMO level and thus could improve the electron-accepting ability of the PF. The emission maxima on the photoluminescence (PL) spectra of the PF, PFQ, PFBT, and PFTP films are 424, 493, 540, and 674 nm, which correspond to the color of blue, green, yellow, and red, respectively. It suggests that the full color of emission can be achieved by different acceptors. The significant positive solvatochromism on the PL spectra in different polar solvents suggests the efficient intramolecular charge transfer in PFTP. However, such charge transfer or heavy-atom effect results in fluorescence quenching and thus reduces the PL efficiencies. By random copolymerizing the TP into the PF, the PL efficiency could be improved. A significantly reduction on the PF emission peak with increasing the TP content suggests the energy transfer between the PF and TP segments. Besides, the characteristics on the electroluminescence (EL) devices of ITO/PEDOT:PSS/emissive layer/Ca/Ag suggest that such energy transfer results in the complete quenching of the PF emission at only 1% TP content in the PFTP01. The maximum external quantum efficiency (EQE) of the EL device based on the PFTP01 is superior to that of the PF due to the reduced LUMO level in matching with the Ca. The CIE 1931 coordinates of the PFTP01 based EL device under the condition of maximum EQE is (0.66, 0.31), which is close to the standard red of (0.66, 0.34) demanded by the National Television System Committee (NTSC). The luminescence characteristics based on the prepared polymers depend on the Förster energy transfer or the intramolecular charge transfer, or heavy-atom fluorescence quenching. The present study suggests that the tuning of the electronic and optoelectronic properties could be achieved by incorporating various acceptors or content into the polyfluorenes.     

Copolymerization of ethylene and 2-vinylnaphtalene with titanium and zirconium catalysts

Copolymerization of ethylene and 2-vinylnaphtalene (VN) has been investigated with dimethylsilylene(tetramethylcyclopentadienyl)(N-tert-butyl)titanium dichloride (1) and rac-isopropylidenebis(indenyl)zirconium dichloride (2) using methylaluminoxane as a cocatalyst. The copolymerization gave the corresponding copolymer in good yield. The catalyst 1 showed higher incorporation of VN than the catalyst 2. Thermal properties of the resulting copolymers were investigated by DSC in comparison with those of poly(ethylene-co-styrene), and poly(ethylene-co-VN) showed higher T_g than poly(ethylene-co-styrene).     

New electroluminescent carbazole-containing conjugated polymer: Synthesis,photophysics, and electroluminescence

A new electroluminescent polymer, poly{9-(2-ethylhexyl)carbazole-2,7-diethynylene-alt-tris[2,5-bis(2-ethylhexyloxy)-1,4-phenylenevinylene]} (PCzE-PPV), is synthesized, and its photophysical and electrochemical properties and electroluminescence (EL) are studied. In solution, an intense photoluminescence (PL) emission with a maximum at about 520 nm is observed. PL decay dynamics in solution are best described by a monoexponential function with a lifetime of 0.76 ns. Thin films exhibit an intense PL emission with a slightly red-shifted maximum at 532 nm compared to that in the solution spectra. The polymer oxidizes and reduces quasi-reversibly. The ionization potential (HOMO level) of 5.3 eV and the electron affinity (LUMO level) of 2.80 eV are evaluated from cyclovoltammetric measurements. The electrochemical bandgap value (2.45 eV) is in good agreement with the optical bandgap value. Using new polymer, light-emitting devices (LEDs) with a luminance higher than 3000 cd m⁻² and low onset voltages at about 3 V are fabricated. The shape of EL spectra of the LEDs is similar to that of PL spectra of the thin films.     

New amphiphilic fluorescent CBABC-type pentablock copolymers containing pyrene group by two-step atom transfer radical polymerization (ATRP) and its self-assembled aggregation

A series of novel amphiphilic fluorescent CBABC-type pentablock copolymers (Py-PMMA-PEG4600-PMMA-Py) were prepared from BAB-type amphiphilic triblock copolymer (PMMA-PEG4600-PMMA) as macroinitiator with various contents of 1-(methacryloyloxyethylamino-carboxylmethyl) pyrene (PyMOI) by atom transfer radical polymerization (ATRP) in toluene using CuBr/2,2-bipyridine as catalyst system. Triblock copolymer (PMMA-PEG4600-PMMA) was prepared by ATRP and obtained from Br-PEG4600-Br as macroinitiator with methyl methacrylate in tetrahydrofuran using the same catalyst. The molecular weights of pentablock copolymers which were reinitiated by PMMA-PEG4600-PMMA macroinitiator were calculated from ¹H NMR spectra up to 42,400 gmol⁻¹. The polydispersity of pentablock copolymers obtained from GPC analysis was narrow between 1.10 and 1.38. The crystallinity of triblock copolymer (PMMA-PEG4600-PMMA) was decreased slightly with incorporating PMMA segment. Introducing the bulky pyrene substituent into pentablock copolymer, the melting temperature was not observed and all pentablock copolymers showed amorphous patterns in wide-angle X-ray scattering (WAXS) due to decrease in the degree of crystallinity of polymer chain because of disturbing regular packing. The temperatures at 10% weight loss (Td₁₀), examined by TG analysis, showed values ranging from 265 to 323 °C in nitrogen and 264 to 313 °C in air. Fluorescence spectra of Py-PMMA-PEG4600-PMMA-Py exhibited stronger excimer emission at ca. 480 nm due to the aggregations of pyrene group formed via interaction of the hydrophobic chains. The more content of PyMOI segment in pentablock copolymers can obtain the higher emission intensity ca. 480 nm. When there were higher PyMOI contents (84.9 wt% PyMOI) in pentablock copolymers, they formed larger aggregates (210 nm) in SEM micrographs. On the other hand, while increasing the concentration of the polymer solution in THF, the morphology was changed from spherical (0.1 mg/mL) to chainlike (1.0 mg/mL) aggregates.