Reverse atom transfer radical polymerization of methyl methacrylate in different solvents

The reverse atom transfer radical polymerization of methyl methacrylate was investigated in different solvents: xylene, N,N‐dimethylformamide, and pyridine. The polymerizations were uncontrolled, using 2,2′‐bipyridine as a ligand in xylene and pyridine because the catalyst (CuBr₂/2,2′‐bipyridine complex) had poor solubility in the xylene system. In the pyridine system, the solubility of the catalyst increased, but the solvent could complex with CuBr₂, which influenced the control of the polymerization. In the N,N‐dimethylformamide system, the catalyst could be dissolved in the solvent completely, but the ? N(CH₃)₂ group in N,N‐dimethylformamide could also complex with CuBr₂, so the polymerization could not be well controlled. The ligand of 4,4′‐di(5‐nonyl)‐2,2′‐bipyridine was also investigated in xylene; the introduction of the ? CH(C₄H₉)₂ group enabled the CuBr₂/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine complex to easily dissolve in xylene, and the polymerizations were well controlled. The number‐average molecular weight increased linearly with the monomer conversion from 4280 to 14,700. During the whole polymerization, the polydispersities were quite low (1.07–1.10). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Controlled polymerization of methylmethacrylate from fumed SiO2 nanoparticles through atom transfer radical polymerization

Atom transfer radical polymerization (ATRP) is a promising method to synthesize well‐defined polymer/inorganic nanoparticles. However, the surface‐initiated ATRP from commercially mass produced inorganic nanoparticles has seldom been studied. In this study, the surface‐initiated ATRP of methylmethacrylate (MMA) from commercially mass produced fumed silica (SiO₂) nanoparticles was investigated. Unlike the ATRP of MMA initiated from a free initiator, the controllability of ATRP of MMA from the surface of fumed silica nanoparticles was much better using ligand 2,2'‐bipyridine (bpy) than N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (PMDETA) as the initiator was immobilized on the surface of the SiO₂ nanoparticles and the presence of the SiO₂ nanoparticles made the CuCl/bpy catalyst system a homogeneous catalyst system and CuCl/PMDETA a heterogeneous one. The appropriate molar ratio of monomer and initiator was essential for preparing controlled PMMA/SiO₂ nanoparticles. The entire process of ATRP of MMA from the surface of SiO₂ nanoparticles was controllable when using bpy as ligand, xylene as solvent and with a monomer to initiator ratio of 300:1. The ¹H NMR results indicated that the PMMA on the surface of the SiO₂ was prepared via ATRP initiated from 4‐(chloromethyl)phenyltrimethoxysilane. The well‐defined PMMA/SiO₂ nanoparticles obtained have good thermal stability and are well dispersed in organic media as proved by TGA, dynamic light scattering and transmission electron microscopy. © 2013 Society of Chemical Industry     

Kinetic study of the atom transfer radical polymerization of n‐docosyl acrylate

The atom transfer radical polymerization (ATRP) of n‐docosyl acrylate (DA) was studied at 80°C in N,N‐dimethylformamide using the carbon tetrabromide/FeCl₃/2,2′‐bipyridine (bpy) initiator system in the presence of 2,2′‐azobisisobutyronitrile (AIBN) as the source of reducing agent. The rate of polymerization exhibits first‐order kinetics with respect to the monomer. The linear relationship between the molecular weight of the resulting poly(n‐docosyl acrylate) with conversion and the narrow polydispersity of the polymers indicates the living characteristics of the polymerization reaction. The significant effect of AIBN on the ATRP of DA was studied keeping [FeCl₃]/[bpy] constant. A probable reaction mechanism for the polymerization system is postulated to explain the observed results. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2147–2154, 2005     

Urotropine as a highly effective and versatile promoter for atom transfer radical polymerization

Atom transfer radical polymerization (ATRP) is a transition metal complex‐catalyzed controlled/‘living’ radical process. Recently, there has been a lot of interest focused on decreasing the catalyst loading and reducing the cost of post‐polymerization purification for ATRP. In this work, urotropine was found to significantly enhance the ATRP of methyl acrylate (MA), methyl methacrylate (MMA) and styrene (St) catalyzed by CuBr/N,N,N′,N′,N″‐pentamethyldiethylenetriamine (PMDETA) and CuBr/tris(2‐(dimethylamino)ethylamine) (Me₆TREN). With the addition of 25 times the amount of urotropine relative to CuBr, well‐controlled polymerizations of MA, MMA and St were obtained at catalyst‐to‐initiator ratios of 0.01, 0.05 and 0.05, respectively, producing the corresponding polymers with molecular weights close to theoretical values and low polydispersities. The catalyst concentration could even be reduced to ppm level at a catalyst‐to‐initiator ratio as low as 0.001 in the polymerization of MA. These results indicate that urotropine is a very effective and versatile promoter for both CuBr/PMDETA and CuBr/Me₆TREN. In the presence of urotropine, the catalyst loading could be reduced by as much as 1000 times. As PMDETA is one of the cheapest ATRP ligands, the combination of urotropine with CuBr/PMDETA could substantially reduce the catalyst loading and the cost of post‐polymerization purification at the industrial scale and thus is promising for potential industrial applications. © 2014 Society of Chemical Industry     

New fluorous bipyridine ligands for copper‐catalyzed atom transfer radical polymerization of methyl methacrylate in the thermomorphic mode

The atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) is often carried out under homogeneous conditions, so the residual metal catalyst in the polymer often influences the quality of the polymer and causes environmental pollution in the long run. Novel CuBr/4,4′‐bis(R_fCH₂OCH₂)‐2,2′‐bpy complexes (R_f = n‐C₉F₁₉, n‐C₁₀F₂₁, or n‐C₁₁F₂₃; 2,2′‐bpy = 2,2′‐bipyridine) are insoluble in toluene at room temperature yet readily dissolve in toluene at elevated temperatures to form homogeneous phases for use as catalysts in the ATRP reaction, and the Cu complexes precipitate again upon cooling. The CuBr/4,4′‐bis(n‐C₉F₁₉CH₂OCH₂)‐2,2′‐bpy system produced the best results (e.g., polydispersity index by gel permeation chromatography = 1.26–1.41), in that the residual Cu content in the polymer was as low as 19.3 ppm when the ATRP of MMA was carried out in the thermomorphic mode. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of vinyl polymers bearing photo‐labile diethylthiocarbamoylthiyl (S2CNEt2) groups via ATRP

Direct synthesis of vinyl polymers functionalized with photo‐labile diethylthiocarbamoylthiyl (S₂CNEt₂) groups was reviewed via three living polymerization procedures: normal atom‐transfer radical polymerization (ATRP), reverse ATRP and photo ATRP. The S₂CNEt₂ group was transferred by mediating the dormant–active species equilibrium in the course of polymerization and eventually ω‐terminating the resulting polymer chain. ATRP of methyl methacrylate (MMA) was successfully performed with a p‐toluenesulfonyl chloride/Cu(S₂CNEt₂)/2,2′‐bipyridine(bpy) or benzoyl peroxide (BPO)/Cu(S₂CNEt₂)/bpy initiation system. The oxidized complex, Cu(S₂CNEt₂)Cl/bpy, catalyzed the reverse ATRP of vinyl monomers initiated with BPO or 2,2′‐azobisisobutyronitrile (AIBN), producing tailor‐made polymers with ω‐S₂CNEt₂ groups and a narrow molecular‐weight distribution. Without external ligands, the living polymerization of vinyl monomers was achieved under the thermal initiation of diethyl 2,3‐dicyano‐2,3‐diphenylsuccinate (DCDPS) in conjunction with Fe(S₂CNEt₂)₃ catalyst. Photo ATRP of MMA and styrene was first realized in the presence of 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA)/Fe(S₂CNEt₂)₃ under UV irradiation at ambient temperature. Copyright © 2004 Society of Chemical Industry     

Structural estimation of particle arrays at air–water interface based on silica particles with well‐defined and highly grafted poly(methyl methacrylate)

Silica nanoparticles with well‐defined, highly grafted dense poly(methyl methacrylate) (MMA) were prepared by surface‐initiated activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP) of methyl methacrylate with an initiator‐fixed silica particle in the presence of air. Two different polymerizations of MMA were carried out under the same conditions using tris[2‐(dimethylamino)ethyl]amine (Me₆TREN) and N,N,N′,N′,N″‐pentamethyldiethylene‐triamine (PMDETA) as the ligand, respectively. In the CuCl₂/PMDETA system, polymerization appeared to be more controlled with a lower polydisperisty compared with the CuCl₂/Me₆TREN system. The monolayer of these particles was formed at the air–water interface using Langmuir‐Blodgett (LB) technique. Multilayers of the particles were fabricated by repetition of LB depositing. A surface pressure–area (π–A) measurement and SEM observation were used to characterize the particle arrays. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Synthesis of methyl methacrylate and N‐aryl itaconimide block copolymers via atom‐transfer radical polymerization

The paper describes the synthesis of block copolymers of methyl methacrylate (MMA) and N‐aryl itaconimides using atom‐transfer radical polymerization (ATRP) via a poly(methyl methacrylate)–Cl/CuBr/bipyridine initiating system or a reverse ATRP AIBN/FeCl₃·6H₂O/PPh₃ initiating system. Poly(methyl methacrylate) (PMMA) macroinitiator, ie with a chlorine chain‐end (PMMA‐Cl), having a predetermined molecular weight (M_n = 1.27 × 10⁴ g mol^?1) and narrow polydispersity index (PDI = 1.29) was prepared using AIBN/FeCl₃·6H₂O/PPh₃, which was then used to polymerize N‐aryl itaconimides. Increase in molecular weight with little effect on polydispersity was observed on polymerization of N‐aryl itaconimides using the PMMA‐Cl/CuBr/Bpy initiating system. Only oligomeric blocks of N‐aryl itaconimides could be incorporated in the PMMA backbone. High molecular weight copolymer with a narrow PDI (1.43) could be prepared using tosyl chloride (TsCl) as an initiator and CuBr/bipyridine as catalyst when a mixture of MMA and N‐(p‐chlorophenyl) itaconimide in the molar ratio of 0.83:0.17 was used. Thermal characterization was performed using differential scanning calorimetry (DSC) and dynamic thermogravimetry. DSC traces of the block copolymers showed two shifts in base‐line in some of the block copolymers; the first transition corresponds to the glass transition temperature of PMMA and second transition corresponds to the glass transition temperature of poly(N‐aryl itaconimides). A copolymer obtained by taking a mixture of monomers ie MMA:N‐(p‐chlorophenyl) itaconimide in the molar ratio of 0.83:0.17 showed a single glass transition temperature. Copyright © 2005 Society of Chemical Industry     

Synthesis of well‐defined poly(methyl methacrylate) nanoparticles by reverse atom transfer radical polymerization in a microemulsion

Well‐defined poly(methyl methacrylate) (PMMA) with an α‐isobutyronitrile group and an ω‐bromine atom as the end groups was synthesized by the microemulsion polymerization of methyl methacrylate (MMA) at 70°C with a 2,2′‐azobisisobutyronitrile/CuBr₂/2,2′‐bipyridine system. The conversion of the polymerization reached 81.9%. The viscosity‐average molecular weight of PMMA was high (380,000), and the polydispersity index was 1.58. The polymerization of MMA exhibited some controlled radical polymerization characteristics. The mechanism of controlled polymerization was studied. The presence of hydrogen and bromine atoms as end groups of the obtained PMMA was determined by ¹H‐NMR spectroscopy. The shape and size of the final polymer particles were analyzed by scanning probe microscopy, and the diameters of the obtained particles were usually in the range of 60–100 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3670–3676, 2006     

The potential of Cu(I)Cl/2,2′‐bipyridine catalysis in a triblock copolymer preparation by atom transfer radical polymerization

The ability of atom transfer radical polymerization (ATRP) in the sequential synthesis of triblock copolymers was examined using Cu(I)Cl/2,2′‐bipyridine catalysis at 110°C in toluene, starting from PMMA macroinitiators terminated with the C‐Br group. The PMMAs were prepared by living anionic or group transfer polymerization (GTP), followed by bromination of the respective active site with Br₂ or N‐bromosuccinimide (NBS). The yield of the terminal bromination in the products of both living polymerizations was 60–64% at best, compared with the yield of the bromination of 1‐methoxy‐(1‐trimethylsilyloxy)prop‐1‐ene (a model of the GTP active site) with NBS, as found by ¹H‐NMR. The PMMA macroinitiators prepared were utilized to start the sequential ATRP, finally affording PMMA‐b‐PBuA‐b‐PSt (M_n 69,100), PMMA‐b‐PSt‐b‐PBuA (M_n 21,300) and PMMA‐b‐PSt‐b‐PMMA (M_n 35,200), which have not yet been synthesized by ATRP. After the second block has been formed, the Br‐unterminated part of PMMA macroinitiator was removed by extraction or repeated precipitation. In the third (last) sequence polymerization, induction periods were observed. The first two triblock copolymers were free of precursors and have M_w/M_n values 1.5–1.6 (SEC). In the course of the last step of PMMA‐b‐PSt‐b‐PMMA synthesis, the content of the PMMA‐b‐PSt precursor slowly decreased with increasing MMA conversion. Still, at ≈90% MMA conversion, about 10–15% of the precursor remained in the product. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3514–3522, 2001     

Fe‐mediated SET‐LRP of MMA and St in the presence of air

In this work, well‐defined homopolymers of methyl methacrylate (PMMA) and styrene (PSt) were prepared via single‐electron‐transfer living radical polymerization using CCl₄ as initiator and Fe(0)/N, N, N′,N′‐tetramethyl‐1,2‐ethanediamine as catalyst. The polymerization was conducted at 25 °C in N,N‐dimethylformamide in the presence of air. It proceeded in a ‘living’ manner, as indicated by the first‐order kinetics behavior, and the linear increase of the number‐average molecular weight (M_{n, GPC}) with conversion was close to the theoretical M_{n, theory}. Solvent and additives have a profound effect on the polymerization. In addition, the PMMA and PSt obtained remained of low dispersity. The chain‐end functionality of the obtained homopolymer of PMMA was characterized by proton nuclear magnetic resonance. A block copolymer of P(MMA‐block‐St) was achieved by using the obtained PMMA as macroinitiator. The living characteristics were further demonstrated by chain extension experiments. Copyright © 2012 Society of Chemical Industry     

Graft copolymerization of methyl methacrylate from brominated poly(isobutylene‐co‐isoprene) via atom transfer radical polymerization

Commercial brominated poly(isobutylene‐co‐isoprene) (BIIR) rubber has been directly used for the initiation of atom transfer radical polymerization (ATRP) by utilizing the allylic bromine atoms on the macromolecular chains of BIIR. The graft copolymerization of methyl methacrylate (MMA) from the backbone of BIIR which was used as a macroinitiator was carried out in xylene at 85 °C with CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as a catalytic complex. The polymerization conditions were optimized by adjusting the catalyst and monomer concentration to reach a higher monomer conversion and meanwhile suppress macroscopic gelation during the polymerization process. This copolymerization followed a first‐order kinetic behavior with respect to the monomer concentration, and the number‐average molecular weight of the grafted poly(methyl methacrylate) (PMMA) increased with reaction time. The resultant BIIR‐graft‐PMMA copolymers showed phase separation morphology as characterized by atomic force microscopy, and the presence of PMMA phase increased the polarity of the BIIR copolymers. This study demonstrated the feasibility of using commercial BIIR polymer directly as a macromolecular initiator for ATRP reactions, which opens more possibilities for BIIR modifications for wider applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43408.     

Synthesis of liquid crystalline–amorphous block copolymers by combination of CFRP and ATRP mechanisms

Block copolymers of liquid crystalline 6‐(4‐cyanobiphenyl‐4′‐oxy) hexyl acrylate (LC6) and styrene (St) were obtained by the combination of two different free‐radical polymerization mechanisms namely conventional free‐radical polymerization (CFRP) and atom transfer radical polymerization (ATRP). In the first part, thermosensitive azo alkyl halide, difunctional initiator (AI), was prepared and then used for CFRP of LC6 monomer. The obtained bromine‐ended difunctional liquid crystalline polymers (PLC6) were used as initiators in ATRP of St, in bulk in conjunction with CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) as catalyst. In the second part, AI was firstly polymerized by CFRP in the presence of St and then the obtained difunctional bromine ended polystyrenes (PSt) were used as initiators in ATRP of LC6 in diphenyl ether solvent in conjuction with CuBr/PMDETA. The spectral, thermal, and optical measurements confirmed a fully controlled living polymerization, which results in formation of ABA‐type block copolymers with very narrow polydispersities. In both cases, blocks of the different chemical composition were segregated in the solid and melt phases. The mesophase transition temperatures of the liquid crystalline block were found to be very similar to those of the corresponding homopolymers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Synthesis and characterization of poly(vinyl chloride‐co‐vinyl acetate)‐graft‐poly[(meth)acrylates] by atom transfer radical polymerization

The graft polymerization of methyl methacrylate and butyl acrylate onto poly(vinyl chloride‐co‐vinyl acetate) with atom transfer radical polymerization (ATRP) was successfully carried out with copper(I) thiocyanate/N,N,N′,N′,N″‐pentamethyldiethylenetriamine and copper(I) chloride/2,2′‐bipyridine as catalysts in the solvent N,N‐dimethylformamide. For methyl methacrylate, a kinetic plot of ln([M]₀/[M]) (where [M]₀ is the initial monomer concentration and [M] is the monomer concentration) versus time for the graft polymerization was almost linear, and the molecular weight of the graft copolymer increased with increasing conversion, this being typical for ATRP. The formation of the graft polymer was confirmed with gel permeation chromatography, ¹H‐NMR, and Fourier transform infrared spectroscopy. The glass‐transition temperature of the copolymer increased with the concentration of methyl methacrylate. The graft copolymer was hydrolyzed, and its swelling capacity was measured. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 183–189, 2005     

Synthesis and characterization of AB‐type copolymers poly(L‐lactide)‐block‐poly(methyl methacrylate) via a convenient route combining ROP and ATRP from a dual initiator

Diblock copolymers of poly(L ‐lactide)‐block‐poly(methyl methacrylate) (PLLA‐b‐PMMA) were synthesized through a sequential two‐step strategy, which combines ring‐opening polymerization (ROP) and atom transfer radical polymerization (ATRP), using a bifunctional initiator, 2,2,2‐trichloroethanol. The trichloro‐terminated poly(L ‐lactide) (PLLA‐Cl) with high molecular weight (M_n,GPC = 1–12 × 10⁴ g/mol) was presynthesized through bulk ROP of L ‐lactide (L ‐LA), initiated by the hydroxyl group of the double‐headed initiator, with tin(II) octoate (Sn(Oct)₂) as catalyst. The second segment of the block copolymer was synthesized by the ATRP of methyl methacrylate (MMA), with PLLA‐Cl as macroinitiator and CuCl/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) as catalyst, and dimethyl sulfoxide (DMSO) was chosen as reaction medium due to the poor solubility of the macroinitiator in conventional solvents at the reaction temperature. The trichloroethoxyl terminal group of the macroinitiator was confirmed by Fourier transform infrared spectroscopy (FTIR) and ¹H‐NMR spectroscopy. The comprehensive results from GPC, FTIR, ¹H‐NMR analysis indicate that diblock copolymers PLLA‐b‐PMMA (M_n,GPC = 5–13 × 10⁴ g/mol) with desired molecular composition were obtained by changing the molar ratio of monomer/initiator. DSC, XRD, and TG analyses establish that the crystallization of copolymers is inhibited with the introduction of PMMA segment, which will be beneficial to ameliorating the brittleness, and furthermore, to improving the thermal performance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Atom transfer radical polymerizations of methyl methacrylate and styrene with an iniferter reagent as the initiator

Three novel iniferter reagents were synthesized and used as initiators for the polymerizations of methyl methacrylate (MMA) and styrene (St) in the presence of copper(I) bromide and N,N,N′,N″,N″‐pentamethyldiethylenetriamine at 90 and 115°C, respectively. All the polymerizations were well controlled, with a linear increase in the number‐average molecular weights during increased monomer conversions and relatively narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight ≤ 1.36) throughout the polymerization processes. The polymerization rate of MMA was faster in bulk than that in solution and was influenced by the different polarities of the solvents. A slight change in the chemical structures of the initiators had no obvious effect on the polymerization rates of MMA and St. The initiator efficiency toward MMA was lower than that toward St. The results of ¹H‐NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrum analysis, and chain‐extension experiments demonstrated that well‐defined poly(methyl methacrylate) and polystyrene bearing photolabile groups could be obtained via atom transfer radical polymerization (ATRP) with three iniferter reagents as initiators. The polymerization mechanism for this novel initiation system was a common ATRP process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Primary amine functionalized polystyrenes by atom transfer radical polymerization

Primary amine functionalized polystyrenes were prepared in quantitative yields by atom transfer radical polymerization using the adduct of 1‐(bromoethyl)benzene with 1‐(4‐aminophenyl)‐1‐phenylethylene as initiator for styrene polymerization in the presence of a copper(I) bromide/N,N,N′,N′,N″‐pentamethyldiethylenetriamine catalyst system. The polymerizations proceeded via a controlled free radical polymerization process to afford quantitative yields of the corresponding primary amine functionalized polystyrenes with predictable molecular weights (M_n = 2 × 10³ to 10 × 10³ g mol^?1), relatively narrow molecular weight distributions (M_w/M_n = 1.03–1.49), well defined chain‐end functionalities and initiator efficiencies as high as 0.92. The polymerization process was monitored by gas chromatographic analysis. The primary amine functionalized polymers were characterized by thin layer chromatography, size exclusion chromatography, potentiometry and spectroscopy. Experimental results are consistent with quantitative functionalization via the 1,1‐diphenylethylene derivative. Polymerization kinetic measurements show that the polymerization reaction follows first order rate kinetics with respect to monomer consumption and the number average molecular weight increases linearly with monomer conversion. © 2003 Society of Chemical Industry     

Synthesis and characterization of poly(n‐butyl methacrylate)‐b‐polystyrene diblock copolymers by atom transfer radical emulsion polymerization

Poly(n‐butyl methacrylate) (PBMA)‐b‐polystyrene (PSt) diblock copolymers were synthesized by emulsion atom transfer radical polymerization (ATRP). PBMA macroinitiators that contained alkyl bromide end groups were obtained by the emulsion ATRP of n‐butyl methacrylate with BrCH₃CHCOOC₂H₅ as the initiator; these were used to initiate the ATRP of styrene (St). The latter procedure was carried out at 85°C with CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine as the catalyst and polyoxyethylene(23) lauryl ether as the surfactant. With this technique, PBMA‐b‐PSt diblock copolymers were synthesized. The polymerization was nearly controlled; the ATRP of St from the macroinitiators showed linear increases in number‐average molecular weight with conversion. The block copolymers were characterized with IR spectroscopy, ¹H‐NMR, and differential scanning calorimetry. The effects of the molecular weight of the macroinitiators, macroinitiator concentration, catalyst concentration, surfactant concentration, and temperature on the polymerization were also investigated. Thermodynamic data and activation parameters for the ATRP are also reported. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2123–2129, 2005     

Graft copolymerization of methylmethacrylate with N‐substituted maleimide‐styrene copolymer by ATRP

Atom transfer radical polymerization (ATRP) was employed to prepare graft copolymers having poly(MBr)‐alt‐poly(St) copolymer as backbone and poly(methyl methacrylate) (PMMA) as branches to obtain heat resistant graft copolymers. The macroinitiator was prepared by copolymerization of bromine functionalized maleimide (MBr) with styrene (St). The polymerization of MMA was initiated by poly(MBr)‐alt‐poly(St) carrying bromine groups as macroinitiator in the presence of copper bromide (CuBr) and bipyridine (bpy) at 110°C. Both macroinitiator and graft copolymers were characterized by ¹H NMR, GPC, DSC, and TGA. The ATRP graft copolymerization was supported by an increase in the molecular weight (MW) of the graft copolymers as compared to that of the macroinitiator and also by their monomodal MW distribution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006