Synthesis of well‐designed polymers carrying saccharide moieties via RAFT miniemulsion polymerization

Two hydrophobic vinyl saccharide monomers based on D ‐glucose and D ‐fructose were polymerized by employing the reversible addition‐fragmentation transfer (RAFT) miniemulsion polymerization technique to prepare well‐designed glycopolymers. Three dithiobenzoate‐RAFT agents [S?C(Ph)S? R], 1‐phenylethyl dithiobenzoate (PED), 2‐phenylprop‐2‐yl dithiobenzoate (PPD), and 2‐cyanoprop‐2‐yl dithiobenzoate (CPD), were used to control the growth of polymer chains. The best results were obtained in the presence of the PPD‐RAFT agent and the formed polymers have polydispersity index's (PDI) lower than 1.15. Under adequate miniemulsion polymerization conditions, a glycopolymer with PDI of 1.1 and molecular weight of 5 × 10⁴ g/mol has been successfully synthesized in a short reaction time of 100 min. Furthermore, some block copolymers containing saccharide segment with butyl or methyl methacrylate were prepared. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and radical polymerization of styrene derivative bearing kojic acid moieties

A styrene derivative ( 1 ) bearing kojic acid moieties was prepared by the base-catalyzed reaction of p-formylstyrene with kojic acid. Hydroxyl groups in 1 were subjected to acetylation. Although 1 did not undergo radical polymerization, the acetylated styrene derivative ( 2 ) showed good radical homo- and copolymerizability. For instance, a polymer having the number average molecular weight (M_n) of 60,000 was obtained in almost quantitative yield (97%) by the polymerization of 2 in chloroform (1.5 M) at 60°C for 36 h using α,α′-azobis(isobutyronitrile) (AIBN, 5 mol %) as an initiator. Under similar conditions, copolymers of 2 with styrene were also obtained in high yield. By partial deacetylation of the copolymer with a triethylamine catalyst, a copolymer containing α-hydroxyketone structures originated from kojic acid moieties was successfully regenerated. The deacetylated copolymer can be crosslinked by complexation with metal salts such as Al³⁺. © 1996 John Wiley & Sons, Inc.     

Functional benzoxazines containing ammonium salt of carboxylic acid: Synthesis and highly activated thermally induced ring‐opening polymerization

1,3‐Benzoxazine monomers having ammonium salt of carboxylic acid have been developed. These 1,3‐benzoxazines 1a and 1b were easily synthesized from the corresponding tetrabutylammonium salts of glycine and β‐alanine, respectively. The glycine‐derived benzoxazine 1a exhibited remarkably high reactivity, which allowed its thermally induced ring‐opening polymerization in bulk at 100 °C, at which N‐methyl‐1,3‐benzoxazine 1d did not undergo the polymerization at all. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis and kinetics of polymerization of hydrophilic monomers: 2,3-dihydroxypropylacrylate and 2,3-dihydroxypropylmethacrylate

Unsaturated monomers containing none, one, or two hydroxyl groups were obtained by the reaction of glycerol (1,2,3-trihydroxypropane) with acrylic and methacrylic chloride. The experimental values of the mole fractions of the different monomers were compared with those theoretically obtained by considering different mechanisms involving two or seven kinetic constants. Agreement between the theoretical and experimental results could only be achieved by assuming that the reactivity of the hydroxyl groups changed with the presence of the substituents. The investigation of the radical polymerizations 2,3-dihydroxypropylacrylate (GA) and 2,3-dihydroxypro- pylmethacrylate (GM) was carried out at several temperatures in water–dioxane solutions. Ultraviolet spectroscopic techniques were used to determine the kinetic constants, and the results were compared with those obtained in the same conditions for methyl acrylate, methyl methacrylate, 2-hydroxyethylacrylate, and 2-hydroxyethylmethacrylate. The values of the ratio k_p/k_t^1/2 for the methacrylic monomer GM were higher than 0.5 L^1/2 mol^−1/2 s^−1/2 at temperatures between 50 and 65 °C. These values exceeded 2 L^1/2 mol^−1/2 s^−1/2 for the acrylic monomer GA, perhaps the highest values reported for this kind of monomer. Electron paramagnetic resonance spectroscopy was also used to study the polymerization of GM. All the polymers were soluble in the reaction mixture until very high conversions, and the gel effect was never detected at monomer concentrations equal to or lower than 1 mol L⁻¹. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1843–1853, 2001     

Synthesis and radical ring‐opening polymerization of vinylcyclopropanes derived from amino acids with hydrophobic moieties

Six 1,1‐disubstituted vinylcyclopropanes (VCP) were synthesized from glycine and amino acids bearing hydrophobic moieties, l ‐alanine, l ‐valine, l ‐leucine, l ‐isoleucine, and l ‐phenylalanine. These VCP derivatives efficiently underwent radical ring‐opening polymerization to afford the corresponding polymers bearing trans‐vinylene moiety in the main chains and the amino acid‐derived chiral moieties in the side chains. The polymers were film‐formable, and in the films of polymers bearing the glycine‐ and alanine‐derived side chains, presence of hydrogen bonding was confirmed by IR analysis. Thermogravimetric analysis of the polymers revealed that the temperatures of 5% weight loss were higher than 300 °C. Differential scanning calorimetry clarified that the polymers were amorphous ones showing glass transition temperatures in a range of 48–80 °C. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3996–4002     

Synthesis of new hybrid monomers and oligomers containing cationic and radical polymerizable vinyl groups and their photoinitiated polymerization

New hybrid vinyl monomers with both cationic- and radical-polymerizable vinyl groups were synthesized by the reaction of bis[1(chloromethyl)-2-(vinyloxy)ethyl]terephthalate ( 3 ) with unsaturated carboxylic acids using 1,8-diazabicyclo[5.4.0]-undecene-7 (DBU) as a base. The reaction of 3 with methacrylic acid 4a was carried out using DBU in DMSO at 70°C for 24 h to give an 86% yield of the hybrid vinyl monomer ( 5a ). Polycondensation of 3 with unsaturated dicarboxylic acids was also performed using DBU to give hybrid vinyl oligomers with radical polymerizable C (DOUBLE BOND) C groups (V_R) in the main chain and cationic polymerizable vinyl ether moieties (V_C) on the side chain. The photopolymerization of these hybrid vinyl compounds proceeded smoothly in bulk using either a cationic photoinitiator such as a sulfonium salt or a radical photoinitiator such as acyl phosphine oxide under UV irradiation. © 1996 John Wiley & Sons, Inc.     

Synthesis and properties of a well‐defined glycopolymer via living radical polymerization

A well‐defined glycopolymer was synthesized to investigate its properties. The glycopolymer was obtained with a narrow polydispersity by nitroxide‐mediated radical polymerization of styrene carrying acetylated lactose and by the subsequent deprotection. The cylindrical structure and helical conformation of the polymer were measured by circular dichroism (CD) spectra. The affinities of the polymers towards lectins depended on the degree of polymerization (DP), and the polymers with higher DP showed stronger affinity. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis,characterization, and water sorption properties of new aromatic polyamides containing benzimidazole and ethylene oxide moieties

New polyamides, containing a benzimidazole side group and ethylene oxide moieties in the structural repeat unit, were synthesized by low‐temperature polycondensation. The aim of this design was to obtain polyamides that were more soluble in common organic solvents and hence had better processability than benzimidazole polyamides while maintaining the water sorption properties characteristic of the latter. The results showed that the number of ether linkages of the repeat unit played an important role in the glass‐transition temperature and in the water sorption properties, the polyamides with one or two ethylene oxide units being more hydrophilic than benzimidazole polyamides. However, the length of the ethylene oxide chain played a minor role in the solubility because the second member of the series, with two ether linkages (i.e., one ethylene oxide unit), reached the same level of solubility as those polyamides with more ethylene oxide moieties. No crystallinity was observed by X‐ray and calorimetric measurements for the new polymers. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 112–121, 2005     

Synthesis,polymerization, and effects on the flame retardancy of boron‐containing styrenic monomers

A boron‐containing styrenic monomer, 5‐benzyl‐2‐phenyl‐5‐(4‐vinylbenzyl)‐[1,3,2]‐dioxaborinane, was synthesized to study the influence of boron on the properties of the homopolymer and copolymer with styrene. A similar monomer without boron was also prepared and polymerized so that the properties of its polymer could be compared with the aforementioned boron‐containing polymers. These monomers were characterized by elemental analysis, mass spectrometry, Fourier transform infrared, and ¹H and ¹³C NMR. The thermal degradation of boron‐containing styrenic polymers was studied by means of Fourier transform infrared, which showed the presence of boric acid as char. The flame‐retardant effect was assessed by the measurement of the limiting oxygen indices and char yields during heating in nitrogen and air. The boron‐containing polymers had higher limiting oxygen indices and gave greater yields of char than those without boron. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem43: 6419–6430, 2005     

Synthesis and characterization of side‐chain liquid crystalline ABC triblock copolymers with p‐methoxyazobenzene moieties by atom transfer radical polymerization

A series of novel side‐chain liquid crystalline ABC triblock copolymers composed of poly(ethylene oxide) (PEO), polystyrene (PS), and poly[6‐(4‐methoxy‐4′‐oxy‐azobenzene) hexyl methacrylate] (PMMAZO) were synthesized by atom transfer radical polymerization (ATRP) using CuBr/1,1,4,7,7‐pentamethyldiethylenetriamine (PMDETA) as a catalyst system. First, the bromine‐terminated diblock copolymer poly(ethylene oxide)‐block‐polystyrene (PEO‐PS‐Br) was prepared by the ATRP of styrene initiated with the macro‐initiator PEO‐Br, which was obtained from the esterification of PEO and 2‐bromo‐2‐methylpropionyl bromide. An azobenzene‐containing block of PMMAZO with different molecular weights was then introduced into the diblock copolymer by a second ATRP to synthesize the novel side‐chain liquid crystalline ABC triblock copolymer poly(ethylene oxide)‐block‐polystyrene‐block‐poly[6‐(4‐methoxy‐4′‐oxy‐azobenzene) hexyl methacrylate] (PEO‐PS‐PMMAZO). These block copolymers were characterized using proton nuclear magnetic resonance (¹H NMR) and gel permeation chromatograph (GPC). Their thermotropic phase behaviors were investigated using differential scanning calorimetry (DSC) and polarized optical microscope (POM). These triblock copolymers exhibited a smectic phase and a nematic phase over a relatively wide temperature range. At the same time, the photoresponsive properties of these triblock copolymers in chloroform solution were preliminarily studied. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4442–4450, 2008     

Synthesis and polymerization of 5‐(methacrylamido)tetrazole,a water‐soluble acidic monomer

The reaction of methacryloyl chloride with 5‐aminotetrazole gave the polymerizable methacrylamide derivative 5‐(methacrylamido)tetrazole ( 4 ) in one step. The monomer had an acidic tetrazole group with a pK_a value of 4.50 ± 0.01 in water methanol (2:1). Radical polymerization proceeded smoothly in dimethyl formamide or, after the conversion of monomer 4 into sodium salt 4‐Na , even in water. A superabsorbent polymer gel was obtained by the copolymerization of 4‐Na and 0.08 mol % N,N′‐methylenebisacrylamide. Its water absorbency was about 200 g of water/g of polymer, although the extractable sol content of the gel turned out to be high. The consumption of 4‐Na and acrylamide (as a model compound for the crosslinker) during a radical polymerization at 57 °C in D₂O was followed by ¹H NMR spectroscopy. Fitting the changes in the monomer concentration to the integrated form of the copolymerization equation gave the reactivity ratios r _4‐Na = 1.10 ± 0.05 and r_acrylamide = 0.45 ± 0.02, which did not differ much from those of an ideal copolymerization. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4333–4343, 2002     

Synthesis of a well-defined glycopolymer by atom transfer radical polymerization

Controlled free radical polymerization of sugar-carrying methacrylate, 3-O-methacryloyl-1,2 : 5,6-di-O-isopropylidene-d-glucofuranose (MAIpGlc) was achieved by the atom transfer radical polymerization (ATRP) technique with an alkyl halide/copper-complex system in veratrole at 80°C. The time–conversion first-order plot was linear and the number-average molecular weight increased in direct proportion to the ratio of the monomer conversion to the initial initiator concentration, providing PMAIpGlc with a low polydispersity. The sequential addition of the two monomers styrene (S) and MAIpGlc afforded a block copolymer of the type PS-b-PMAIpGlc. The acidolysis of the homo- and block copolymers gave well-defined glucose-carrying water-soluble polymers PMAGlc and PS-b-PMAGlc, respectively. The amphiphilic PS-b-PMAGlc block copolymer exhibited a microdomain surface morphology with spherical PS domains in a PMAGlc matrix. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2473–2481, 1998     

Free radical and nitroxide mediated polymerization of hydroxy–functional acrylates prepared via lipase–catalyzed transacylation reactions

3‐Hydroxypropyl acrylate, 4‐hydroxybutyl acrylate, 2‐methyl‐3‐hydroxypropyl acrylate, 2‐hydroxypropyl acrylate, neopentyl glycol acrylate, glyceryl acrylate, and dihydroxyhexyl acrylate were prepared via transacylation reaction of methyl acrylate with diols and triols catalyzed by Candida antarctica lipase B. After removal of the enzyme by filtration and the methyl acrylate by distillation, the monomers were polymerized via free radical polymerization (FRP) with azobisisobutyronitrile as initiator and nitroxide mediated polymerization (NMP) employing Blocbuilder? alkoxyamine initiator and SG‐1 free nitroxide resulting in hydroxy functional poly(acrylates). The NMP kinetics are discussed in detail. In addition, the polymers obtained by FRP and NMP are compared and the results are related to the amount of bisacrylates that are present in the initial monomer mixtures resulting from the transacylation reactions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2610–2621, 2010     

Synthesis of biocompatible and thermally sensitive poly(N‐vinylcaprolactam) nanogels via inverse miniemulsion polymerization: Effect of the surfactant concentration

The goal of this study was to develop a new route to prepare thermally responsive polymer nanogels. Poly(N‐vinylcaprolactam) nanogels were prepared via inverse miniemulsion polymerization (W/O) at 70 °C using n‐hexadecane as a nonpolar continuous phase, potassium persulfate as an initiator, and N,N′‐methylenebisacrylamide as a crosslinker. Sorbitan monooleate (Span 80) was used as surfactant and its influence on the polymerization kinetics and on the colloidal characteristics of the nanogels were principally investigated. It was observed that the addition of a strong “lipophobe” is required to stabilize the resulting miniemulsion. The nanogels were characterized in terms of morphology, size, zeta potential, and thermoproperties using transmission electron microscopy and dynamic light scattering. It was observed that all the nanogels obtained collapsed when the lower critical solution temperature (LCST) was raised. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3932–3941, 2010     

Two-Dimensional polymerization of supramolecular assemblies: Synthesis and bilayer polymerization of lipids containing α-methylene-substituted acyl chains

Polymerization of lipid assemblies may be usefully employed to alter the properties of the assemblies. The possible locations of the reactive group in the lipids include (1) the chain terminus, (2) the head group, and (3) near the lipid backbone. The third strategy yields polymerized assemblies which retain their head group functionality and lipid chain motion. We have designed and synthesized new members of this later category by the use of 2-methylene-substituted acyl chains. The main transition temperature (T_m) from gel to liquid crystalline phase of hydrated bilayers of 1-palmitoyl-2-(2-methylene)palmitoyl-sn-glycero-3-phosphocholine ( 1 ) and the disubstituted 1,2-bis(2-methylenepalmitoyl)-sn-glycero-3-phosphocholine ( 2 ) were 33.6 and 25.3°C, respectively. The T_m of the mono-substituted 1-oleoyl-2-(2-methylene)palmitoyl-sn-glycero-3-phosphocholine ( 3 ) bilayers was detected in a range from ?15 to ?10°C by x-ray diffraction. Hydrated bilayers of each individual lipid were successfully polymerized with a water-soluble initiator, azobis(2-amidinopropane) dihydrochloride (AAPD). These results indicate the lipid 2-methylene groups are accessible to the water interface. Thermal polymerization of the mono-substituted lipids in aqueous suspensions with AAPD, yielded oligomers. However the bis-2-methylene PC ( 2 ) was successfully polymerized to yield stabilized crosslinked bilayers. © 1994 John Wiley & Sons, Inc.     

Dispersion polymerization of vinyl monomers in supercritical carbon dioxide in the presence of drug molecules: A one‐pot route for the preparation of controlled delivery systems

The polymerization of 1‐vinyl‐2‐pyrrolidone in supercritical carbon dioxide in the presence of ibuprofen as a model drug was investigated as a new one‐pot process for the preparation of polymer‐based drug delivery systems (DDSs). The composites were prepared at 65 °C and P = 31–42 MPa by changing the initial concentration of the drug and the concentration of a crosslinking agent and that of a hydrophobic comonomer. The effects of these parameters on the performances of the polymerization and on the in vitro release kinetics of ibuprofen were studied. In all the experiments, part of the drug was entrapped inside the polymer particles and dissolved more slowly with respect to the pure compound. Copolymerization with methyl methacrylate was the most effective route to obtain a DDS with sustained temporal release of the drug molecule. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7429–7446, 2008     

Synthesis and modeling of new phosphorus‐containing acrylates

New methacrylate monomers containing phosphonic acid or both phosphonic and carboxylic acids were synthesized through the reaction of t‐butyl α‐bromomethyl acrylate with triethyl phosphite followed by the selective hydrolysis of the phosphonate or t‐butyl ester groups with trimethylsilyl bromide and trifluoroacetic acid. The copolymerization of these monomers with 2‐hydroxyethylmethacrylate was investigated with photodifferential scanning calorimetry at 40 °C with 2,2′‐dimethoxy‐2‐phenyl acetophenone as a photoinitiator. Quantum mechanical tools were also used to understand the mechanistic behavior of the polymerization reactions of these synthesized monomers. The propagation and chain‐transfer reactions were considered and rationalized. A strong effect of the monomer structure on the rate of polymerization was observed. The polymerization reactivities of the monomers increased with decreasing steric hindrance and/or increasing hydrogen‐bonding capacity because of the hydrolysis of the phosphonate and the t‐butyl ester groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2574–2583, 2005     

Synthesis of statistical and block copolymers containing adamantyl and norbornyl moieties by reversible addition‐fragmentation chain transfer polymerization

The synthesis of statistical and block copolymers, consisting of monomers often used as resist materials in photolithography, using reversible addition‐fragmentation chain transfer (RAFT) polymerization is reported. Methacrylate and acrylate monomers with norbornyl and adamantyl moieties were polymerized using both dithioester and trithiocarbonate RAFT agents. Block copolymers containing such monomers were made with poly(methyl acrylate) and polystyrene macro‐RAFT agents. In addition to have the ability to control molecular weight, polydispersity, and allow block copolymer formation, the polymers made via RAFT polymerization required end‐group removal to avoid complications during the photolithography. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 943–951, 2010     

Synthesis and in vitro activity of platinum containing 2‐oxazoline‐based glycopolymers

We report the synthesis of glyco(poly(2‐oxazoline)s) functionalized with Pt(II) units for targeted tumor applications. To this end, poly(2‐ethyl‐2‐oxazoline‐block‐2‐(3‐butenyl)‐2‐oxazoline) is modified with thiol‐modified acetyl protected glucose and galactose, respectively, and terpyridine (tpy) units using thiol‐ene photoaddition. Deprotection of the sugars with sodium methoxide and treatment with Pt(COD)Cl₂ applying a mild synthesis route yields polymers with monosaccharide targeting moieties and cytotoxic Pt(II) units. The polymers and intermediates are characterized by ¹H nuclear magnetic resonance spectroscopy and size exclusion chromatography. Subsequently, the hemolytic activity, induction of erythrocyte aggregation as well as the cytotoxicity against mouse fibroblast L929 cells, human embryonic kidney cells HEK 293, and human hepatocytes HepG2 are studied. The comparison to cisplatin, the standard for cancer therapy, demonstrates the potential of the presented system. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2703–2714     

Microwave‐assisted nitroxide‐mediated radical polymerization of acrylamide in aqueous solution

The present work describes a combination of microwave irradiation as a heating source and water as a solvent for carrying out a living/controlled polymerization of acrylamide. Reasonable results were obtained for a nitroxide‐mediated radical polymerization (NMP) with a combination of a conventional hydrosoluble radical initiator and a β‐phosphonylated nitroxide. The microwave enhancement of the polymerization was found to depend on the mode of irradiation, i.e., either a dynamic (DYN) mode or an pulse (SPS) mode. The former mode corresponded to a dynamic control of the temperature by way of a high initial microwave power, and in this case, no specific microwave effect was observed. On the other hand, in the SPS mode, which is a pulsed power mode, the result showed a strong acceleration of the polymerization process (>50 times) without the loss of the living/controlled polymerization characteristics, which is relevant with a reinitiation of the polyacrylamide macroinitiator even after 100% of conversion. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009