Atom Transfer Radical Polymerization Of MMA Research Articles

Synthesis of chlorinated polypropylene grafted poly(methyl methacrylate) using chlorinated polypropylene as macro-initiator via atom transfer radical polymerization and its application in lithium ion battery

Chlorinated polypropylene grafted poly(methyl methacrylate) (CPP-g-PMMA) was successfully synthesized using AlCl3/FeCl2·4H2O/triphenylphosphine (PPh3) as catalyst and CPP as macro-initiator for the first time. Kinetics study revealed that the grafting reaction was consistent with the characteristic of atom transfer radical polymerization (ATRP). The effect of AlCl3, as activator on the ATRP of MMA, was investigated and a possible polymerization mechanism was proposed. Finally, the CPP-g-PMMA membranes were assembled into batteries. The ionic conductivity and charge–discharge capacity of the membranes were investigated. It was found that the electrochemical performance of the graft products was better than that of CPP, which can be ascribed to the graft PMMA.

Synthesis and characterization of pentablock copolymers based on Pluronic® L64 and poly(methyl methacrylate)

The synthesis and characterization of amphiphilic pentablock copolymers based on Pluronic® L64 (PEO13-PPO30-PEO13) and poly(methyl methacrylate) (PMMA), synthesized via atom transfer radical polymerization (ATRP) is reported. The L64 is first transformed into a bifunctional ATRP macroinitiator which was subsequently chain extended with MMA by ATRP to afford PMMA-b-L64-b-PMMA pentablock copolymers. The chemical structure of the synthesized amphiphilic block copolymers is characterized by FTIR, 1H NMR spectroscopy, and gel permeation chromatography (GPC). The GPC profiles of the block copolymers clearly show an increase in molar mass after the ATRP of MMA and monomodal molecular weight distributions for all the samples. Finally, preliminary studies on their aggregation behavior in aqueous solution have also been investigated by measuring the scattering light intensity as function of block copolymer concentration to estimate the critical aggregation concentration (CAC). The CAC decreases with increasing of hydrophobic content in copolymer, i.e., ∼25 and ∼15 mg/mL, respectively, is estimated for the pure L64 and PMMA13-b-L64-b-PMMA13. Further, with increase in temperature, the CAC is found to decrease that is attributed to the dehydration of the PEO segments at higher temperatures.

Synthesis of Amylopectin Macro-Initiator for Graft Copolymerization of Amylopectin-g-Poly(Methyl Methacrylate) by ATRP (Atom Transfer Radical Polymerization)

Graft copolymer of Amylopectin and PMMA was synthesized by atom transfer radical polymerization (ATRP) method. The hydroxyl groups of amylopectin partially substituted with tert-butyl a-bromoisobutyrate to form tert-butyl a-bromoisobutyrate (TBBiB ) groups. This compound is known as an efficient macro-initiator for ATRP process. This research, aimed to obtain a bio based polymer of Amylopectin, in which the amylopectin was used as macro-initiator in the ATRP of MMA. The experiment was carried out in the homogeneous system under temperature range of 40 – 70°C in DMSO solution using TEA as catalyst. The modified amylopectin-TBBiB then was grafted to methyl methacrylate trough ATRP. Product characterization indicates that the graft copolymer Amylopectin-g-PMMA is efficient and the obtained product owns well defined structures

MALDI‐TOF Analysis of Halogen Telechelic Poly(methyl methacrylate)s and Poly(methyl acrylate)s Prepared by Atom Transfer Radical Polymerization (ATRP) or Single Electron Transfer‐Living Radical Polymerization (SET‐LRP)

Poly(methyl methacrylate)s (PMMA)s and poly(methyl acrylate)s (PMA)s are prepared by atom transfer radical polymerization (ATRP) or single electron transfer‐living radical polymerization (SET‐LRP) using methyl dichloroacetate (MDCA) and ethyl dibromoacetate (EDBA) as bifunctional initiators. The chain‐end functionality is determined by MALDI‐TOF mass spectrometry. The target PMMA (Mn = 2000 g mol−1) and PMA (Mn = 2000 g mol−1) samples obtained by ATRP of MMA and MA with MDCA as initiator have 12 and 81 mol% bis‐chloro end groups, respectively; those prepared by SET‐LRP have 57 and 100 mol% bis‐chloro end groups, respectively. The PMMAs obtained by ATRP or SET‐LRP with EDBA have no bromine end groups. image

Synthesis of Poly(methyl methacrylate)-poly(poly(ethylene glycol) methacrylate)-polyisobutylene ABCBA Pentablock Copolymers by Combining Quasiliving Carbocationic and Atom Transfer Radical Polymerizations and Characterization Thereof

Novel, unique amphiphilic pentablock terpolymers consisting of the highly hydrophobic polyisobutylene (PIB) mid-segment attached to the hydrophilic combshaped poly(poly(ethylene glycol) methacrylate) (PPEGMA) polymacromonomer chains, which are coupled to poly(methyl methacrylate) (PMMA) outer segments were synthesized by the combination of quasiliving carbocationic polymerization and atom transfer radical polymerization (ATRP). First, a bifunctional PIB macroinitiator was prepared by quasiliving carbocationic polymerization and subsequent quantitative chain end derivatizations. Quasiliving ATRP of PEGMAs with different molecular weights (Mn = 188, 300 and 475 g/mol) led to triblock copolymers which were further reacted with MMA under ATRP conditions to obtain PMMA-PPEGMA-PIB-PPEGMA-PMMA ABCBA-type pentablock copolymers. It was found that slow initiation takes place between the PIB macroinitiator and PEGMA macromonomers with higher molecular weights via ATRP. ATRP of MMA with the resulting block copolymers composed of PIB and PPEGMA chain segments led to the desired block copolymers with high initiating efficiency. Investigations of the resulting pentablock copolymers by DSC, SAXS and phase mode AFM revealed that nanophase separation occurs in these new macromolecular structures with average domain distances of 11-14 nm, and local lamellar self-assembly takes place in the pentablocks with PPEGMA polymacromonomer segments of PEGMAs with Mn of 118 g/mol and 300 g/mol, while disordered nanophases are observed in the block copolymer with PEGMA having molecular weight of 475 g/mol. These new amphiphilic block copolymers composed of biocompatible chain segments can find applications in a variety of advanced fields.

Superhydrophobic surfaces of electrospun block copolymer fibers with low content of fluorosilicones

Abstract A series of well-defined poly[methyl(3,3,3-trifluoropropyl)siloxane]- b -poly(methyl methacrylate) (PMTFPS- b -PMMA) diblock copolymers with low content of PMTFPS were synthesized by atom transfer radical polymerization (ATRP) of MMA from PMTFPS macroinitiators (PMTFPS-Br). The polymerization result reveals that the ATRP of MMA from PMTFPS-Br is fist-order with respect to MMA under different polymerization conditions, demonstrating a typical characteristic of living polymerization. The results also show that PMTFPS- b -PMMA diblock copolymers can exhibit a total surface tension ( γ S ) varying from 25.28 mN/m to 21.87 mN/m with the change of PMTFPS contents from 2.6 wt% to 22.2 wt%. Moreover, the water contact angles of electrospun PMTFPS- b -PMMA surfaces could be higher than 150° with water roll-off angles less than 10°, which denotes a superhydrophobic property. However, the electronspinning conditions, especially the concentration of spinning solution, would have important effect on the surface morphology, surface composition and wetting behavior of electrospun films. It was found that bead-free fibers with uniform diameter as well as good superhydrophobic property could be prepared on condition that the polymer concentration of spinning solution was as high as 32 wt% in the mixed solvent of DMF and THF.

A novel conducting amphiphilic diblock copolymer containing regioregular poly(3-hexylthiophene)

Amphiphilic rod-coil diblock copolymers combining the conductive features of a conjugated polymer and nanoscale morphologies arising from micro-phase separation of dissimilar blocks are attractive as potential materials for electronic applications. The synthesis and properties are reported for a novel amphiphilic diblock copolymer containing a block of regioregular poly(3-hexylthiophene) (P3HT) and poly(methyl methacrylate-random-2-hydroxyethyl methacrylate) (P(MMA-r-HEMA)) as the hydrophilic block. Well-defined rod-coil P3HT-b-P(MMA-r-HEMA) amphiphilic diblock copolymers with molar masses of around 11,000 and low molar mass dispersities (ĐM) below 1.5 were successfully synthesized via the combination of quasi-living Grignard metathesis (GRIM) polymerization and atom transfer radical polymerization (ATRP). P3HT was first obtained in a regioregular form with an average molecular weight of around 7,200 g/mol and ĐM below 1.3. Post-polymerization end-group modifications of the asobtained P3HT were then successfully realized to give a macroinitiator for the ATRP of MMA and HEMA co-monomers, resulting in the P3HT-b-P(MMA-r-HEMA) diblock copolymers. The structure and properties of the resulting diblock copolymers were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectroscopy and modulated differential scanning calorimetry (MDSC). Open image in new window

Synthesis of photocleavable poly(methyl methacrylate-block-d -lactide) via atom-transfer radical polymerization and ring-opening polymerization

The synthesis and characterization of a photocleavable block copolymer containing an ortho-nitrobenzyl (ONB) linker between poly(methyl methacrylate) and poly(d-lactide) blocks is presented here. The block copolymers were synthesized via atom transfer radical polymerization (ATRP) of MMA followed by ring-opening polymerization (ROP) of d-Lactide and ROP of d-lactide followed by ATRP of MMA from a difunctional photoresponsive ONB initiator, respectively. The challenges and limitations during synthesis of the photocleavable block copolymers using the difunctional photoresponsive ONB initiator are discussed. The photocleavage of the copolymers occurs under mild conditions by simple irradiation with 302 nm wavelength UV light (Relative intensity at 7.6 cm: 1500 μW/cm2) for several hours. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4309–4316

Synthesis of cyclohexanone formaldehyde resin‐methylmethacrylate block‐graft copolymers via ATRP

AbstractWell defined block‐graft copolymers of cyclohexanone‐formaldehyde resin (CFR) and methylmethacrylate (MMA) were prepared via atom transfer radical polymerization (ATRP). In the first step, cyclohexanone formaldehyde resin (CFR) containing hydroxyl groups were modified with 2‐bromopropionyl bromide. Resulting multifunctional macroinitiator was used in the ATRP of MMA using copper bromide (CuBr) and N,N,N′,N″,N″‐pentamethyl‐diethylenetriamine (PMDETA) as catalyst system at 90°C. The chemical composition and structure of the copolymers were characterized by nuclear magnetic resonance (1H‐NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and molecular weight measurement. Molecular weight distributions of the CFR graft copolymers were measured by gel permeation chromatography (GPC). Mn values up to 19,000 associated with narrow molecular weight distributions (polydispersity index (PDI) < 1.6) were obtained with conversions up to 49%. Coating properties of synthesized graft copolymers such as adhesion and gloss values were measured. They exhibited good adhesion properties on Plexiglas substrate. The thermal behaviors of all polymers were conducted using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis of Star Polymers of Styrene and Alkyl (Meth)acrylates from a Porphyrin Initiator Core via ATRP

A free-base tetrabromoporphyrin, 15,20-tetrakis(4-(2-methyl-2-bromopropoxy)phenyl)-21H,23H- porphine (2), was synthesized in high yield (91%) by the esterification of 5,10,15,20-tetrakis(4-hydroxyphenyl)- 21H ,2 3H-porphine (1) with 2-bromo-2-methylpropanoyl bromide. The free-base porphyrin (2) was demonstrated to be suitable as an initiator for atom transfer radical polymerization (ATRP) of methyl methacrylate giving porphyrin-core star-poly(methyl methacrylate) with conversions of up to 98% (CuIBr, N-(n-propyl)-2-pyridyl- methanimine, toluene, 90 °C). UV-vis spectroscopic analysis demonstrated that a degree of complexation of Cu(II) by the porphyrin core occurred during the polymerization. To avoid Cu(II) complexation, zinc(II) 10,- 15,20-tetrakis(4-(2-methyl-2-bromopropoxy)phenyl)-21H,23H-porphine (4) was synthesized from the free-base porphyrin (2) and employed as an initiator in the ATRP of MMA, giving the corresponding Zn porphyrin-core star-PMMA. The free-base porphyrin (2) was also employed as an initiator for the polymerization of styrene, methyl acrylate, butyl methacrylate, octadecyl acrylate and the copolymerization of isobutyl methacrylate (IBMA) and trifluoroethyl methacrylate (TFEMA), in all cases giving star polymers with conversions of 33-87%. Basic hydrolysis of a porphyrin-core star-polystyrene polymer cleaved the ester linkages about the porphyrin, liberating the individual polystyrene chains which had a number-average molecular weight approximately one-fourth that of the precursor star polymer and a narrow polydispersity index (Mw/Mn ) 1.15) thereby demonstrating efficient initiation from the porphyrin core. Palladium(II) 10,15,20-tetrakis(4-(2-methyl-2-bromopropoxy)phenyl)-21 H,- 23H-porphine (3) was synthesized from the free-base porphyrin (2) and employed as an initiator in the ATRP of MMA but the polymerization was completely inhibited. Pd(II) was introduced into the star polymer cores by heating either a solution of the porphyrin-core star-PMMA or the Zn porphyrin-core star-PMMA with Pd II Cl2 in benzonitrile. Pt(II) was introduced into a star polymer core by heating a solution of the Zn porphyrin-core star- PIBMA-co-TFEMA with Pt II Cl2 in benzonitrile. UV-vis spectroscopic analysis confirmed the synthesis of Pd- (II) and Pt(II) porphyrin complexes and photoluminescent spectroscopy confirmed the luminescent properties of the materials.

Photoresponsive poly(methyl methacrylate)2–(polystyrene)2 miktoarm star copolymer containing an azobenzene moiety at the core

AbstractWe prepared a novel miktoarm star copolymer with an azobenzene unit at the core via combination of atom transfer radical polymerization (ATRP) and nitroxide‐mediated free radical polymerization (NMP) routes. For this purpose, first, mikto‐functional initiator, 3, with tertiary bromide (for ATRP) and 2,2,6,6‐tetramethylpiperidin‐1‐yloxy (TEMPO) (for NMP) functionalities and an azobenzene moiety at the core was synthesized. The initiator 3 thus obtained was used in the subsequent living radical polymerization routes such as ATRP of MMA and NMP of St, respectively, to give A2B2 type miktoarm star copolymer, (PMMA)2‐(PSt)2 with an azobenzene unit at the core with controlled molecular weight and low polydispersity (Mw/Mn < 1.15). The photoresponsive properties of 3 and (PMMA)2‐(PSt)2 miktoarm star copolymer were investigated. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1396–1403, 2006

The synthesis of CDA- g-PMMA copolymers through atom transfer radical polymerization

Graft copolymer of cellulose diacetate (CDA) and PMMA was synthesized through atom transfer radical polymerization (ATRP). The residual hydroxyl groups on the diacetate cellulose reacted with 2-bromoisobutyryl bromide to yield 2-bromoisobutyryl groups known to be an efficient initiator for ATRP. Then the functional CDA was used as macroinitiator in the ATRP of MMA. The polymerization was carried out in the system of PMDETA/CuBr/1,4-dioxane under 70 °C. Kinetic study indicated that the polymerization is first order. Copolymers were characterized by 1H NMR and GPC. The molecular weight increased without any trace of the macroinitiator, and the polydispersities were low.

Synthesis of binary mixed homopolymer brushes by combining atom transfer radical polymerization and nitroxide-mediated radical polymerization

This communication describes a novel strategy to synthesize binary mixed homopolymer brushes from mixed self-assembled monolayers (SAMs) on silica substrates by combining atom transfer radical polymerization (ATRP) and nitroxide-mediated radical polymerization (NMRP). Mixed SAMs terminated by ATRP and NMRP initiators were prepared by coadsorption of two corresponding organotrichlorosilanes from toluene solutions. Mixed poly(methyl methacrylate) (PMMA)/polystyrene (PS) brushes were synthesized by ATRP of MMA at 80 °C followed by NMRP of styrene at 115 °C. Corresponding ‘free’ initiators were added into the solutions to control the polymerizations. We have found that the brush thickness increases with molecular weight in a nearly linear fashion. For a series of binary brushes consisting of PMMA of molecular weight of 26,200 and PS of various molecular weights, we have observed a transition in water contact angles with increasing PS molecular weight after CH 2Cl 2 treatment. Moreover, binary mixed polymer brushes with comparable molecular weights for two grafted polymers undergo reorganization in response to environmental changes, exhibiting different wettabilities.

Synthesis of fully acrylic thermoplastic elastomers by atom transfer radical polymerization (ATRP), 2. Effect of the catalyst on the molecular control and the rheological properties of the triblock copolymers

The ATRP of MMA was initiated by α,ω-dibromo poly(n-butyl acrylate) in the presence of NiBr 2 (PPh 3)2 leading to poly(MMA)-b-poly(nBuA)-b-poly(MMA) triblock copolymers (MnBM). The initiation of the MMA polymerization is slow compared to the chain propagation, which results in PMMA blocks of broad molecular weight distribution (MWD). In order to improve this situation, several experimental parameters were varied. CuBr/dNBipy was first substituted for NiBr 2 (PPh 3 ) 2 , the results being, however, even worse. Then, the halide exchange was considered by substituting CuCl for CuBr. The CuCl/dNBipy catalyst proved superiority over the originally used NiBr 2 (PPh 3 ) 2 system. Finally, the addition of an excess of CuCl 2 (deactivator) to the CuCl/dNBipy catalyst was very beneficial in decreasing the MWD of the PMMA blocks. Indeed, the SEC chromatograms are monomodal and narrow from the very beginning of the polymerization. The rheological analysis of the MnBM triblocks synthesized in the presence of each of the aforementioned catalytic systems confirmed differences in the molecular control of the copolymerization reaction.

New AB or ABA type block copolymers: atom transfer radical polymerization (ATRP) of methyl methacrylate using iodine-terminated PVDFs as (macro)initiators

PMMA homopolymer with CF3(CF2)2CF2- end group was prepared by the ATRP of MMA using CF3(CF2)2CF2-I as an initiator and copper(I) salts/bipy catalysts. This indicated the production of perfluorobutyl radicals by ATRP mechanism and successful polymerization by them. Di- and triblock copolymers were also prepared by the ATRP of MMA using iodine-terminated PVDF as (macro)initiators. The kinetic plots (ln[M]o/[M] vs. time) showed nearly first-order with respect to monomer concentration and the Mn,NMR of block copolymers increased linearly with conversion. However, iodine-terminated PVDF showed low initiator efficiency because propagating rate was much faster than initiating rate