Synthesis and Evaluation of Some Novel Polymeric Surfactants Based on Aromatic Amines Used as Wax Dispersant for Waxy Gas Oil

Dicarboxy methyl ethoxylated aniline and 1,3‐dicarboxy methoxy benzene were synthesized as intermediate monomers to prepare six polyester surfactants. The first three of them were obtained by polyesterification of dicarboxy methoxy ethoxylated (EO=10) aniline with polyethylene glycol (M. wt.; 400, 600, 1000). The product named as An E₁₀ 400, An E₁₀ 600, and An E₁₀ 1000. The later three was obtained by polyesterification of 1, 3 dicarboxymethoxy benzene with the same PEG at different molecular weights. The product named as; R 400, R 600, and R 1000. These polyesters were characterized by FT.ir, and GPC. These polyesters were evaluated as pour point depressants of a mixed blend of Egyptian Western desert gas oil, (PP=18^oC). The obtained data showed that, the maximum reduction of pour point was obtained with An E₁₀ 1000 (ΔPP=15°C) and R 1000 (ΔPP=18°C) regarding to the two groups of polyesters respectively. Blends from these compounds were done. From the results, it was found that, the blend IV exhibit the maximum depression of pour point, (ΔPP=24°C). The photomicrographic investigation for the change of wax crystals morphology and size as the results of using the pour point dispersants was carried out after the treatment by the blends. The photomicrographic pictures showed a great modification of wax crystals was obtained as a result of dispersion of wax by the additives. The results were compared with a commercial additive at 1000 ppm. It was found that, its ΔPP=18°C. This work was extended to study the surface active properties of these polyesters at liquid/air interface. The obtained data were used to explain the discrepancy of these polyesters toward pour point depression.     

Preparation the Esters of Oleic Acid-Maleic Anhydride Copolymer and Their Evaluation as Flow Improvers for Waxy Crude Oil

Five comb-like copolymers derived from oleic acid-maleic anhydride were prepared and then esterified by long-chain fatty alcohol (POMA C_n), where n = 18, 20, 22. These polymers were characterized by FTIR and ¹H NMR analysis. The molecular weight was determined by using gel permeation chromatography (GPC). The prepared copolymers were investigated as flow improvers and pour point depressants (PPD) for crude oil. From the evaluation, it was found that, the maximum depression of PP was obtained by (POMA₂ C₂₂) with long-chain alcohol (C₂₂–OH) from 27°C to 15°C (ΔPP_3000ppm = ?12°C). On the other side, it was remarked that no depression obtained by (POMA₂ C₁₈), which esterified by alcohol (C₁₈–OH) at the same condition. The depression of pour point effectiveness was discussed on the light of polymers structure, molecular weights, and their concentrations. By analysis the results of the rheological flow properties, it was found that the POMA₂ C₂₂ enhanced the Bingham yield values (τ_β). The τ_β for crude oil without additives against 15, 27, and 39°C were 0.286, 0.131, and 0.075 Pa respectively, whereas the τβ for the treated crude oil with POMA₂ C₂₂ were 0.027, 0.022 and 0.010 Pa at 3000 ppm at the same temperatures. By using the photomicrography analysis, it was found that, the wax morphology was greatly modified to fine dispersed crystals of compact size.     

Spectroscopic studies and determination of the formation constants and thermodynamic parameters for a new water-soluble Co(II) Schiff-base complex and some imidazole derivatives

A new water-soluble Co(II) Schiff-base complex, sodium[{N,N′-bis(5-sulfosalicylidene)-1,8-diamino-3,6-dioxaoctan}cobalt] dihydrate, abbreviated as Na₂[Co(II)L], was synthesized and characterized. The formation constants and thermodynamic parameters for the interaction of this complex with imidazole (Im) and 1-methylimidazole (MeIm) were determined spectroscopically in aqueous solution, ethanol/water (10/90), and methanol/water (10/90) under physiological conditions (pH?=?7), constant ionic strength (I?=?0.1?mol?dm^?3 KNO₃), and various temperatures ranging from 294 to 310?K. Our spectroscopic and thermodynamic results show that this adduct formation is endothermic and the positive values of ΔS _f° make ΔG _f° negative. The trend in variation of ΔH _f° and ΔS _f° for Im is in the order water?>?methanol?>?ethanol, but for MeIm it is in the opposite order which is related to the hydrogen bonding between solvents and these donors. Formation constants between MeIm and Na₂[Co(II)L] in these three solvents are larger than for Im which depends on the electron donation of methyl on MeIm.     

Effect of nanocomposite of attapulgite/EVA on flow behavior and wax crystallization of model oil

Nanocomposites of attapulgite (ATT)/ethylene vinyl acetate copolymer (EVA) were prepared with organically modified ATT covering in EVA. Organically modified ATT was prepared using KH550 and organic acid. The effect of nano-hybrid on the flow behavior of model oil containing 15?wt% wax was evaluated. The wax crystallization and crystal morphology of the model oil at low temperature were observed by polarizing optical microscopy (POM). The results indicated that the nano-hybrid with long-chain organic acid-modified ATT exhibited a better effect compared with the nano-hybrid with short-chain organic acid-modified ATT, pure EVA. In addition, it is interesting to note that EVA (VA?=?32%)/stearic acid-modified ATT composite polymeric pour-point depressant (PPD) S-AtPPD(32) provided better cold-flow improvement for the model oil than EVA (VA?=?32%)-modified nano-SiO₂ composite PPD N-SiPPD (32) with a low dose, which resulted in a regular, bar-shaped, and uniform arrangement of wax morphologies. The pour point of the model oil was reduced from 30°C to ?1°C when doped at 200?ppm S-AtPPD(32).     

Styrene-Maleic Anhydride Copolymer Esters as Flow Improvers of Waxy Crude Oil

Four comb-like copolymers derived from styrene-maleic anhydride copolymer were prepared and characterized by FTIR, ¹H-NMR and elemental analysis. The molecular weight was determined using GPC and their intrinsic viscosity was measured. The prepared polymers were investigated as pour point depressants and flow improvers for waxy crude oil and it was found that, the maximum depression was obtained by the sample that has long branch chain (PPD4) from 27°C to ?3°C (ΔPP = 30°C, at 10000 ppm). While, the minimum depression was exhibited by short branch chain, PPD1 (ΔPP = 21°C) at the same conditions. The effect of these polymers on the rheology and flow properties of Qarun waxy crude oil was investigated. It was found that the Bingham yield value (τ_β) decreased from 6.0 pa.s. to 0.5 pa.s. for PPD4 at 27°C and 10,000 ppm. The dynamic viscosity also decreased from 110 m pa.s. to 24 m pa.s. for the same sample and the same conditions.     

Effects of alkyltrimethylammonium bromide surfactants on the kinetics of the oxidation of tris(1,10-phenanthroline)iron(II) by azido-pentacyanocobaltate(III) complex

The redox reaction between tris(1,10-phenanthroline)iron(II), [Fe(phen)₃]²⁺, and azido-pentacyanocobaltate(III), [Co(CN)₅N₃]^3? was investigated in three cationic surfactants: dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB) and cetyltrimethylammonium bromide (CTAB) in the presence of 0.1?M NaCl at 35°C. Second-order rate constant in the absence and presence of surfactant, k_w and k_ψ, respectively, were obtained in the concentration ranges DTAB?=?0???4.667?×?10^?4?mol?dm^?3, TTAB?=?0–9.364?×?10^?5?mol?dm^?3, CTAB?=?0???6.220?×?10^?5?mol?dm^?3. Electron transfer rate was inhibited by the surfactants with premicelllar activity. Inhibition factors, k_w/k_ψ followed the trend CTAB?>?TTAB?>?DTAB with respect to the surfactant concentrations used. The magnitudes of the binding constants obtained suggest significant electrostatic and hydrophobic interactions. Activation parameters ΔH^≠, ΔS^≠, and E_a have larger positive values in the presence of surfactants than in surfactant-free medium. The electron transfer is proposed to proceed via outer-sphere mechanism in the presence of the surfactants.     

Electroactive block copolymers

Synthesis, characterization and properties of microphase separated mixed (ionic and electronic) conducting or MIEC block copolymers are reported. Poly{[ω-methoxyocta(oxyethylene) methacrylate]-block-(4-vinylpyridine)}, abbreviated as P[MG8–4VP], and poly{(3-methylthiophene)-block-[(ω-methoxyocta(oxyethylene) methacrylate]}, abbreviated as P[3MT-MG8], have been synthesized. Differential scanning calorimetry (DSC) studies indicate that the polymers form a microphase separated structure. P[3MT-MG8] can be doped with I₂ and LiClO₄ to generate electronic and ionic conducting microdomains, respectively. For the P[3MT-MG8] series, bulk electronic conductivity as high as 1×10⁻³ S cm⁻¹ and bulk ionic conductivity as high as 6.6×10⁻⁷ S cm⁻¹ is observed at 30°C. This work represents a new concept in the area of electroactive polymers and should impact the microelectrochemical device industry.     

Effect of modified nano-silica/EVA on flow behavior and wax crystallization of model oils with different wax contents

The nano-hybrid pour-point depressant (PPD) was prepared with organically modified nano-silica covering in EVA. The effects of modified nano-silica/EVA on the flow behavior and wax crystallization of model oils with different wax contents were evaluated. Compared with pure EVA and nano-silica/EVA, modified nano-silica/EVA exhibited a better effect, when doped with 500?ppm, the pour point of the model oil containing 20?wt% wax was reduced from 33°C to 0°C. However, it is noteworthy that pour point cannot accurately reflect the effect of YSiO2/EVA as cold flow improver for a high wax content. The crystal morphology and crystallization behavior of the model oils at low temperature were also observed using polarizing optical microscopy (POM). The results indicated that modified nano-silica/EVA can reduce the size of the wax crystals and disperse the wax crystals by heterogeneous nucleation.     

Internal motion in some aromatic polyesters and linear aromatic chains

Low-temperature internal motions of the following polyesters have been investigated by broad line nuclear magnetic resonance: poly(methylene terephthalates) (2–6 methylene groups), poly[1,4-(dimethylene)cyclohexylene terephthalate], poly(diethyleneglycol terephthalate), poly(1,2-propylene terephthalate), poly(1,4-phenylene terephthalate), poly(2,2,3,3,4,4-hexafluoropentamethylene terephthalate), poly[1,4-phenylenebis(dimethyl) siloxane], and poly(2,6-dimethylphenylene oxide). No complex line structure was found for any of the samples. Molecular motions in the polyesters appear to be restricted by polar forces arising from the ester groups. Above—196°C. the line width decreases smoothly with increasing temperatures for all polymers except poly[1,4-(dimethylene)cyclohexylene terephthalate] and poly[1,4-phenylenebis(dimethyl)siloxane]. These two show a definite transition in line width at ?20°C. and +12°C., respectively, caused by the onset of considerable internal motion. At ?196°C. the lattices are rigid except for polymers containing methyl groups: poly(1,2-propylene terephthalate), poly[1,4-phenylenebis(dimethyl) siloxane], and poly(2,6-dimethylphenylene oxide). Internal motion that can be ascribed to be a reorientation of the methyl groups is present at ?196°C. for these three polymers, as is demonstrated by comparison of experimental second moments and those calculated on the basis of various models.     

Characterization of polypropylenes prepared with bis‐indenyl type metallocene and MgCl2‐supported TiCl4 catalyst systems

The homo‐polypropylene: m‐PP, prepared with rac‐Me₂Si[2‐n‐Pr‐4‐(9‐Phenanthryl)‐Ind]₂ZrCl₂, showed 99.6% of [mmmm] and 162.8°C of melting temperature (Tm). This polymer was compared by TREF analysis with the homo‐polypropylene: Ti‐PP, which was produced by our latest MgCl₂‐supported TiCl₄ catalyst system and showed 99.0% of [mmmm] and 165.7°C of Tm. It was indicated that m‐PP has narrower stereoregurality distribution than Ti‐PP and Tm of the fraction eluted from m‐PP at the highest temperature range is 163.6°C, while that from Ti‐PP reaches to 167.3°C. The characters and advantages of each polymer are discussed on the basis of these results. In addition, an advantage of this metallocene was made clear by characterization of polypropylenes copolymerized with ethylene.     

Ionic liquids from the cationic cobalt(III) Schiff base complex, [Co(acacen)L2][Tf2N] (acacen = N,N′-bis(acetylacetone)ethylenediamine,Tf2N = bis(trifluoromethanesulfonyl)amide)

Ionic liquids comprising cationic cobalt(III) complexes [Co(acacen)L₂][Tf₂N] (L?=?3-butylpyridine (1), 1-butylimidazole (2); acacen?=?N,N′-bis(acetylacetone)ethylenediamine, Tf₂N?=?bis(trifluoromethanesulfonyl)amide) were prepared. 1 is a liquid at room temperature and exhibits a glass transition at ?12?°C, whereas 2 is a solid at room temperature with a melting point of 74.6?°C and glass transition temperature of ?15?°C upon cooling from the melt. These salts are reddish brown diamagnetic materials that are stable against air and water; these properties differ from those of the corresponding iron(III) salt. Desorption of the axial ligands of 1 and 2 occurs at 180 and 207?°C, respectively.     

Two-step one-electron transfer reaction of chromium(III) complex containing levodopa and uridine with N-bromosuccinimide

[Cr^III(LD)(Urd)(H₂O)₄](NO₃)₂?·?3H₂O (LD?=?Levodopa; Urd?=?uridine) was prepared and characterized. The product of the oxidation reaction was examined using HPLC. Kinetics of the oxidation of [Cr^III(LD)(Urd)(H₂O)₄]²⁺ with N-bromosuccinimide (NBS) in an aqueous solution was studied spectrophotometrically, with 1.0–5.0?×?10^?4?mol?dm^?3 complex, 0.5–5.0?×?10^?2?mol?dm^?3 NBS, 0.2–0.3?mol?dm^?3 ionic strength (I), and 30–50°C. The reaction is first order with respect to [Cr^III] and [NBS], decreases as pH increases in the range 5.46–6.54 and increases with the addition of sodium dodecyl sulfate (SDS, 0.0–1.0?×?10^?3?mol?dm^?3). Activation parameters including enthalpy, ΔH*, and entropy, ΔS*, were calculated. The experimental rate law is consistent with a mechanism in which the protonated species is more reactive than its conjugate base. It is assumed that the two-step one-electron transfer takes place via an inner-sphere mechanism. A mechanism for this reaction is proposed and supported by an excellent isokinetic relationship between ΔH* and ΔS* for some Cr^III complexes. Formation of [Cr^III(LD)(Urd)(H₂O)₄]²⁺ in vivo probably occurs with patients who administer the anti-Parkinson drug (Levodopa), since Cr^III is a natural food element. This work provides an opportunity to identify the nature of such interactions in vivo similar to that in vitro.     

Co‐Conformational Isomerism in a Neutral Ion‐Paired Supramolecular System

Two different counter‐ion‐free host–guest complexes have been prepared and isolated. These compounds were formed from two equally and opposite doubly‐charged species, the viologen guests 1 a ²⁺ and 1 b ²⁺ and the anti‐disulfodibenzo[24]crown‐8 [ DSDB24C8] ^2? host, which gave rise to the 1:1 neutral complexes [ 1 a?DSDB24C8 ] and [ 1 b?DSDB24C8 ]. These species are held together by hydrogen bonding and π stacking, as well as strong electrostatic interactions. The investigation of these neutral ion‐paired supramolecular systems in solution and in the solid state allowed us to establish their co‐conformational preferences. Compound [ 1 a?DSDB24C8 ], with small methyl groups as substituents on the viologen unit, may adopt three different geometries, 1) an exo nonthreaded, 2) a partially threaded, and 3) a threaded arrangement, depending on the relative spatial orientation between the host and guest: The partially‐threaded structure is preferred in solution and in the solid state. The presence of bulky tert‐butylbenzyl groups in the viologen moiety in compound [ 1 b?DSDB24C8 ] restricts the possible geometrical arrangements to one: The exo nonthreaded arrangement. This structure was confirmed in the solid state by X‐ray crystallography. The stability of the neutral complexes in solution was determined by UV/Vis spectrophotometry. The stoichiometry of the complexes was established by continuous variation experiments, and overall equilibrium constants and ΔG° values were determined on the basis of dilution experiments. The results observed are a consequence of only the intrinsic stability of the complexes as there are no additional contributions from counter ions.     

Submicron carbon-based hybrid nano-pour-point depressant with outstanding pour point depressant and excellent viscosity depressant

We have investigated the effective utilization potential of carbon nanomaterials in the field of pour point depressants, and reported three kind of carbon-based hybrid nano-pour-point depressants with different dimensions. In this paper, poly-α-olefins-acrylate high-carbon ester pour point depressant (PAA-18) was prepared by esterification and polymerization as the basic pour point depressant. Then, the basic pour point depressant PAA18 was modified by solvothermal method with graphene oxide (GO), carbon nanospheres (Cna) and carbon nanotubes (OCNTs). The morphology and structure of the composites were analyzed by SEM, FTIR and XRD. The results showed that PAA18 was successfully in situ polymerized on GO, Cna and OCNTs. We took the simulated oil as the experimental object, and evaluated its pour point, rheological properties and wax crystal morphology, and achieved excellent results. In the three carbon-based hybrid nano-pour-point depressants with different carbon contents, the oxidation carbon nanotubes composite pour point depressant (PAA18-1 % OCNTs) with carbon content of 1 % had the best pour point and viscosity reduction effect when the dosage was 1250 ppm, which could make the pour point of the simulated oil containing wax decrease by 16 °C. PAA18-1 % OCNTs reduced the pour point by 5 °C more than PAA18. This paper provides reference for the application of carbon nanomaterials in the field of pour point depressant.     

Structure of ethylene–chlorotrifluoroethylene copolymers

The structures of copolymers of ethylene and chlorotrifluoroethylene have been studied by infrared, nuclear magnetic resonance, and x-ray diffraction techniques. Copolymers varying in ethylene composition from 80 to 50 mole-% were prepared at a number of different temperatures with a peroxide catalyst system. Compositions of 50/50 mole ratio were found to be semicrystalline and to have melting points as high as 241°C. These materials were found to be copolymers with a high degree of one-to-one alternation. They were similar in structure to 1:1 copolymers which had been reported previously by other workers who used a triethylboron catalyst system. The x-ray evidence indicated that the copolymers prepared with the peroxide catalysts were not stereoregular. A hexagonal unit cell with a theoretical density of 1.70 g/cc was determined for the alternating one-to-one copolymer by x-ray techniques. A value of 262°C was determined for the melting point of the theoretical 100% alternating one-to-one copolymer. Values of ΔH_? = 4500 cal/mole and ΔS_? = 8.4 cal/deg-mole were also calculated for the alternating 1:1 copolymer. The preferred conformation of the material appears to be a “kinked” structure with the crystalline phase having ethylene units in one chain lining up opposite chlorotrifluoroethylene units in the adjacent chain. Polar association which can occur between fluorine and hydrogen atoms in this arrangement may account in part for the relatively high melting point of the alternating one-to-one copolymers.     

Acyl- und Alkylidenphosphane. XXIII [1]. Synthese und Struktur der [Bis(trimethylsilylsulfano)methyliden]phosphane

Acyl- and Alkylidenephosphines. XXIII. Synthesis and Structure of [Bis(trimethylsilylsulfano)methylidene]phosphines Analogous to the phenyl derivative 1a [2] tert-butyl- 1b , mesityl- 1c and methylbis-(trimethylsilyl)phosphine 1 d react with carbon disulfide to give the corresponding [bis(trimethylsilylsulfano)methylidene]phosphines 4 . Only in case of the mesitylphosphine 1 c the intermediate compounds 2 and 3 could be detected by n.m.r. spectroscopic methods; thermally unstable [bis(trimethylsilylsulfano)methylidene]methylphosphine 4 d dimerizes rapidly [1]. [Bis(trimethylsilylsulfano)methylidene]phenylphosphine 4 a crystallizes in the monoclinic centrosymmetric space group P2₁/c with following dimensions of the unit cell determined at ?95 ± 3°C: a = 1386.4(8); b = 1036.0(7); c = 1281.7(8) pm; ß = 101.23(4)°; Z = 4. An X-ray structure determination (R = 0.032) proves the constitution of this compound as already derived from its nmr spectra. Characteristic bond lengths and angles are: P?C 170; P? C(phenyl) 183; C? S 176; S? Si 219 pm; C? P?C 107; P?C? S 124 and 120; S? C? S 116 and C? S? Si 111°.     

Acyl- und Alkylidenarsane. VI. Vergleichende Untersuchungen zur Struktur von Bis (2,2-dimethylpropionyl) phenylarsan und -phosphan

Acyl- and Alkylidenearsines. VI. Comparative Studies on the Structures of Bis(2,2-di-methylpropionyl)phenylarsine and -phosphine . Bis(2,2-dimethylpropionyl)phenylarsine 1a [19] and -phosphine 1b [20] prepared from the corresponding bis(trimethylsilyl) derivative and 2,2-dimethylpropionyl chloride, crystallize in the monoclinic space group P2₁/c with following dimensions of the unit cell determined at a temperature of measurement of ?70 ± 3°C/?73 ± 3°C: a = 1449.3(7)/1468.3(3); b = 1050.0(5)/985.9(2); c = 1138.5(4)/1159.4(4) pm; β = 108.27(3)/105.61(3)°; Z = 4. X-ray structure determinations (R_w = 0.044/0.044) reveal distances of 205 and 191 pm between the pnicogen and the carbon atom of the carbonyl group which, as in similar trifluoromethyl compounds [2], are definitely elongated with respect to standard values of 194 and 183 pm. Further characteristic mean bond lengths and angles are: As? C(phenyl) 194; P? C(phenyl) 184; C?O 119/121; C(O)? C 153/154; C(O)? As? C(O) 91; C(O)? P? C(O) 95; As? C? O 120; P? C? O 120; As? C(O)? C 117 and P? C(O)? C 118°.     

Synthesis and Characterization of Four-Arm Star Poly(ϵ-caprolactone)-Block-Poly(cyclic-carbonate methacrylate) Copolymers by Combining Ring-Opening Polymerization With Atom Transfer Radical Polymerization

Well-defined four-arm star poly(?-caprolactone)-block-poly(cyclic carbonate methacrylate) (PCL-b-PCCMA) copolymers were synthesized by combining ring-opening polymerization (ROP) with atom transfer radical polymerization (ATRP). First, a four-arm poly(?-caprolactone) (PCL) macroinitiator [(PCL-Br)₄] was prepared by the ROP of ?-CL catalyzed by stannous octoate at 110°C in the presence of pentaerythritol as the tetrafunctional initiator followed by esterification with 2-bromoisobutyryl bromide. The sequential ATRP of CCMA monomer was carried out by using the (PCL-Br)₄ tetrafunctional macroinitiator (MI) and in the presence of CuBr/2, 2′-bipyridyl system in DMF at 80°C with [(MI)]:[CuBr]:[bipyridyl] = 1:1:3 to yield block polymers with controlled molecular weights (M_n (NMR) = 10700 to 27300 g/mol) by varying block lengths and with moderately narrow polydispersities (M_w/M_n = 1.2–1.4). Block copolymers with different PCL: PCCMA copolymer composition such as 50:50, 70:30 and 74:26 were prepared with good yields (48-74%). All these block copolymers were well characterized by NMR, FTIR and GPC and tested their thermal properties by DSC and TGA.     

Thermal dissociation of SmMnO3

The phase equilibria for the reduction of SmMnO₃ with hydrogen were studied by the static method using a circulation vacuum setup in conjunction with XRD analysis of quenched solid phases. It was established that, over a temperature range of 973–1123 K and a pressure range of 10^?10–10^?16 Pa, SmMnO₃ dissociates by the reaction (1/2)Sm₂O₃ + MnO + (1/4)O₂; in this case, the temperature dependence of the equilibrium oxygen pressure and the Gibbs energy change can be described by the equations log $p_{O_2 } $ [Pa] = 25.35 ? 39150/T ± 0.1, ΔG°_T, kJ/mol = 187.62 ? 0.09T ± 1.62, respectively. Based on the experimental data, the standard thermodynamic functions of formation of SmMnO₃ from elements were calculated: ΔH°_T = ?1485.706 kJ/mol and ΔS°_T = 244.39 J/(mol K).     

Synthesis of methyl methacrylate,styrene, and isobutylene multiblock copolymers using atom transfer and cationic polymerization

ABCBA‐type pentablock copolymers of methyl methacrylate, styrene, and isobutylene (IB) were prepared by the cationic polymerization of IB in the presence of the α,ω‐dichloro‐PS‐b‐PMMA‐b‐PS triblock copolymer [where PS is polystyrene and PMMA is poly(methyl methacrylate)] as a macroinitiator in conjunction with diethylaluminum chloride (Et₂AlCl) as a coinitiator. The macroinitiator was prepared by a two‐step copper‐based atom transfer radical polymerization (ATRP). The reaction temperature, ?78 or ?25 °C, significantly affected the IB content in the resulting copolymers; a higher content was obtained at ?78 °C. The formation of the PIB‐b‐PS‐b‐PMMA‐b‐PS‐b‐PIB copolymers (where PIB is polyisobutylene), prepared at ?25 (20.3 mol % IB) or ?78 °C (61.3 mol % IB; rubbery material), with relatively narrow molecular weight distributions provided direct evidence of the presence of labile chlorine atoms at both ends of the macroinitiator capable of initiation of cationic polymerization of IB. One glass‐transition temperature (T_g), 104.5 °C, was observed for the aforementioned triblock copolymer, and the pentablock copolymer containing 61.3 mol % IB showed two well‐defined T_g's: ?73.0 °C for PIB and 95.6 °C for the PS–PMMA blocks. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3823–3830, 2005