Polymerization of N-alkyl-substituted itaconimides and N-(alkyl-substituted phenyl)itaconimides and characterization of the resulting polymers

N-alkyl-substituted itaconimides (RII) and N-(alkyl-substituted phenyl)itaconimides (RPhII) with various alkyl substituents were prepared and polymerized in the presence of a radical or anionic initiator to give high molecular weight polymers in high yields. The effects of the alkyl substituents on the polymerization reactivities were investigated. It has been revealed that RII and RPhII have the highest polymerization reactivity compared with other itaconic and citraconic derivatives including dialkyl itaconates and citraconimides. The structure and some properties of poly(RII) and poly(RPhII) were examined. These polymers were found to have excellent thermal stability, better than poly (dialkyl itaconate)s. © 1994 John Wiley & Sons, Inc.     

N‐Isopropylacrylamide/monoalkyl itaconate copolymers and N‐isopropylacrylamide/itaconic acid/dimethyl itaconate terpolymers

Temperature‐ and pH‐sensitive copolymers and terpolymers of N‐isopropylacrylamide (NIPAAm) with itaconic acid (IA), monomethyl itaconate (MMeI), monobutyl itaconate (MBuI), monooctyl itaconate (MOcI), monocetyl itaconate (MCeI), and dimethyl itaconate (DMI) were prepared by free radical solution polymerization method. The dependence of coil‐to‐globule transition on pH and composition, molecular structures, and reactivities of monoalkyl itaconates, molecular weight distributions, and glass transition temperatures of copolymers and terpolymers were investigated using FT‐IR and UV–visible spectroscopic techniques, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and acid–base titration methods. The temperature‐/pH‐dependent coil‐to‐globule transition measurements showed that, upon increasing the content and length of alkyl chains, the lower critical solution temperatures (LCSTs) were shifted to higher temperatures. This meant that with increase in the length of hydrophobic alkyl chain in the monoitaconates intramolecular intreactions between the carboxyl groups were suppressed and LCSTs increased. The aqueous solution behaviors of NIPAAm/IA/DMI terpolymers also revealed that, even if the terpolymer hydrophobicity is increased by adding DMI units, the presence of IA units overcame the decrease in hydrophilicity of the terpolymers. The presence of DMI units in the terpolymers balanced the hydrophilic character of IA. DSC results supported the ones obtained from the pH‐dependent coil‐to‐globule transition measurements. An increase in both the chain length of alkyl groups attached to the monoitaconates and the contents of the mono‐ and dialkyl itaconates in the copolymers and terpolymers decreased the T_gs. In the case of NIPAAm/IA and NIPAAm/MMeI copolymers, the presence of the carboxyl groups forming hydrogen bonds increased the T_g, while the monoalkyl and dialkyl itaconates such as MBuI, MOcI, MCeI and DMI lead to a decrease in T_g of copolymers and terpolymers because of the suppression of intramolecular interactions (resulting from the ? COOH and ? COO^? groups) through the longer alkyl spacers. The dependence of the thermosensitivity of these NIPAAm copolymers and terpolymers on different conditions of pH, and the nature and content of comonomers suggests that they can be useful in biotechnology and drug delivery applications which involve small changes in pH and temperature. Copyright © 2009 John Wiley & Sons, Ltd.     

Reactivity and Characterization of the Radical Copolymerization of Itaconic Acid with Some Conventional Monomers

Abstract

Radical copolymerizations of itaconic acid (IA) with acrylamide (Am), N-vinyl pyrrolidone (NVP), ethyl methacrylate (EMA), and methyl methacrylate (MMA) were carried out in dioxane in the presence of azobisisobutyronitrile as the initiator at 65°C. The monomer reactivity ratios (r ₁, r ₂), Q, and e for IA with the four monomers were determined. The reactivity ratios show a tendency toward alternation, while the Q and e of IA indicate that it is an electron-accepting monomer. The polymers obtained were characterized by FT-IR, x-ray diffraction, intrinsic viscosity, and thermal stability measurements.     

Investigation of the effect of type and concentration of ionizable comonomer on the collapse behavior of N-isopropylacrylamide copolymer gels in water

This work was done to investigate the effect of three different ionizable components (acrylic acid, AA; itaconic acid, IA; maleic acid, MA) on the volume phase transitions and swelling equilibria of thermoshrinking type N-isopropylacrylamide (NIPAAM) gels in water. NIPAAM copolymer gels were synthesized by free radical crosslinking copolymerization of NIPAAM with each of AA, IA, and MA, the difference being both between configurations and carboxyl group numbers, and pK values, in the presence of N,N′-methylene-bis-acrylamide (MBAAM). The influence of comonomer concentrations (1, 5, and 10 mol %), MBAAM content (0.0096, 0.0193, and 0.0288 g), and comonomer type (AA, IA, and MA) on the external views, the percentages of equilibrium mass, and volume swellings [S %(m), S % (v)], the number-average molecular weight between crosslinks (M̄_c), effective crosslinking densities (ν_e), the change of the collapse temperatures, and swelling ratios in the swelling–shrinking process of the gels were examined. It was observed that phase transition temperature and swelling degree in the case of MA having a cis configuration and higher pK value are larger than those of the samples containing IA and AA. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1847–1855, 1999     

Terpolymerization of ethyl methacrylate,N‐phenylmaleimide,and itaconic acid

The terpolymerization of ethyl methacrylate (EMA), N‐phenylmaleimide (NPMI), and itaconic acid (IA) was investigated. The terpolymer composition was determined by elemental analysis and ¹H NMR spectroscopy. The reactivity ratios of the three binary systems (EMA/NPMI, EMA/IA, and NPMI/IA) were calculated and used for the calculation of the terpolymer composition with the terminal model equations. A comparison between the experimental and theoretical compositions was made. The rate of the terpolymerization process was measured dilatometrically at two total monomer concentrations; this was done to establish the presence of intermolecular interactions between the investigated monomers. The thermal analysis of the obtained terpolymers was performed by thermogravimetric analysis. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3180–3187, 2003     

Network structure and swelling–shrinking behaviors of pH‐sensitive poly(acrylamide‐co‐itaconic acid) hydrogels

pH‐sensitive poly(acrylamide‐co‐itaconic acid) [P(AAm/IA)] hydrogels were prepared by radiation induced copolymerization of acrylamide (AAm) and itaconic acid (IA) at various ratios. Swelling and shrinking behaviors of these hydrogels were found greatly dependent on the composition of the hydrogel and pH of the buffer solution. The basic structural parameters of the P(AAm/IA) networks such as the molecular weight between crosslinks (M _c) and polymer–solvent interaction parameter (χ) were also determined using the modified Flory‐Rehner equations. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2586–2594, 2004     

The synthesis of biscitraconimides and polybiscitraconimides

A series of N-alkylene biscitraconimides was synthesized from the corresponding N-alkylene-biscitraconamic acids or directly from itaconic anhydride and a homologous series of aliphatic diamines, H₂N(CH₂)_nNH₂, where n = 2 through 12. The biscitraconamic acids were synthesized from the α,ω-diamino-alkanes and itaconic anhydride. Isomerization of itaconic anhydride to citraconic anhydride occurs in the presence of the diamines to yield biscitraconamic acids instead of bisitaconamic acids expected and observed in similar studies. The intermediate biscitraconamic acids or the biscitraconimides were polymerized thermally between 175 and 225°C to tough ambered-colored films of polybiscitraconimides that exhibit good thermal stability.     

Synthesis and solution properties of comblike poly(mono-n-alkyl itaconates). I. Poly(monodecyl itaconate)

The monoester of itaconic acid with n-decyl alcohol was prepared and polymerized. The polymer was fractionated and characterized by viscometry, size-exclusion chromatography (SEC) and light scattering. Some of the common semiempirical relations for flexible and rigid polymers were used in order to obtain the unperturbed dimensions and the conformational parameters. Thermodynamic and dimensional parameters were determined and calculated. The results are compared with those reported previously for similar compounds.     

Base-catalyzed polymerization of maleimide and some derivatives and related unsaturated carbonamides

Basic catalysts in dimethylacetamide solution initiated the polymerization of maleimide to yield a low molecular weight polymer which has a copolymer structure. Approximately 75–85% of the recurring units are formed by hydrogen transfer and 15–25% by vinyl polymerization, as shown by hydrolysis, to yield aspartic acid on the one hand and ammonia and polymaleic acid on the other. Several maleimide derivatives have been prepared, but none has given a high molecular weight polymer by basic catalysis. Some unsaturated carbonamides such as p-vinylbenzamide, mono-N-acrylyl-hexamethylenediamine, and mono-N-acrylyl-p-phenylenediamine have been synthesized and polymerized by basic catalysts. Polymers with low molecular weights were obtained, but the complete structures of all these polymers were not established.     

Enzyme-catalyzed synthesis of natural and unnatural polysaccharides

Synthesis of natural and unnatural polysaccharide was achieved via “enzymatic polymerization” by utilizing a glycoside hydrolase as catalyst. Particularly, hyaluronan, chondroitin, and their derivatives belonging to glycosaminoglycans have been prepared using sugar oxazoline monomers designed on the basis of the concept “transition-state analogue substrate”. The oxazoline derivatives of N-acetylhyalobiuronate [GlcAβ(1→3)GlcNAc] and N-acetylchondrosine [GlcAβ(1→3)GalNAc], which have the repeating disaccharide structures of hyaluronan and chondroitin, respectively, were successfully polymerized by the catalysis of hyaluronidase, giving rise to synthetic hyaluronan and chondroitin. Their 2-substituted oxazoline derivatives were also polymerized to the corresponding N-acylated hyaluronan and chondroitin derivatives. Furthermore, N-acetylchondrosine oxazoline derivatives sulfated at the C4, the C6, and both the C4 and C6 of the GalNAc unit were catalyzed by hyaluronidase; the monomer sulfated at the C4 was polymerized to chondroitin 4-sulfate with well-defined structure, whereas the other two monomers were exclusively hydrolyzed to the corresponding disaccharides. These different kinds of natural and unnatural polysaccharides having relatively high molecular weights were produced in all cases by the catalysis of hyaluronidase. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5014–5027, 2006     

Conducting hydrogels based on semi‐interpenetrating networks of polyaniline in poly(acrylamide‐co‐itaconic acid) matrix: synthesis and characterization

In this work, acrylamide/itaconic acid copolymeric hydrogels are prepared by free radical polymerization initiated by redox initiators of potassium persulfate and N ,N ,N ′,N ′‐tetramethyl ethylene diamine; N ,N ′methylene bisacrylamide was employed as a crosslinking agent. Aniline monomer was absorbed in the network of poly(acrylamide‐co‐itaconic acid) P(AAm‐co‐IA) hydrogel and followed by gamma radiation induced polymerization at room temperature. The novel semi‐interpenetrating network was comprised of linear polyaniline immersed in P(AAm‐co‐IA) matrix. Electrical conductivity of the hydrogels was measured using four‐probe technique. The conductivities for the prepared hydrogels are found to increase from 5.5 × 10^?7 S cm^?1 for P(AAm‐co‐IA) alone to 4.4 × 10^?3 S cm^?1 for semi‐interpenetrating polymer network P(AAm‐co‐IA)/polyaniline. Thus, a new composite hydrogel with good conductive properties also displaying enhanced mechanical strength and pH sensitivity was prepared. Copyright © 2017 John Wiley & Sons, Ltd.     

Description of the turbidity measurements near the phase transition temperature of poly(N-isopropyl acrylamide) copolymers: the effect of pH, concentration, hydrophilic and hydrophobic content on the turbidity

Absorbance values between 300 and 800 nm of aqueous solutions of poly(N-isopropyl acrylamide-co-itaconic acid-9.80), poly(N-isopropyl acrylamide-co-itaconic acid-52.05) and poly(N-isopropyl acrylamide)s containing Tegomer H-Si 2111 end groups and/or blocks were measured using a Shimadzu 160-A UV-visible spectrometer. Turbidities obtained from these absorbance values were used to interpret the macromolecular phase transition from a hydrophilic to a hydrophobic structure of the polymers. The effects of comonomer type and content, concentration of the solutions, pH and temperature on the coil-globule transition were discussed in terms of turbidity form factor, β related to size and shapes of particles and calculated by using the simplified form of Debye equation.The results presented in this work show that the presence of Tegomer H-Si 2111 (Si containing end groups and/or blocks) or high amount of itaconic acid (IA) in the chains prevent a collapse transition from hydrated extended coils to hydrophobic globules, which aggregate and form a separate phase (β<2). Furthermore, it was observed that in the case of concentrated solutions intermolecular hydrophobic interactions between isopropyl groups overcame the repulsive forces resulting from the ionized carboxylic acid groups of IA or surface active nature of Si containing hydrophobic groups (β>2). This stage of the transition corresponds to macroscopic phase separation after an intramolecular process.     

Anionic living polymerization of styrenes containing electron-withdrawing groups

Six styrene derivatives containing electron-withdrawing groups were synthesized and polymerized with anionic initiators in THF to afford stable anionic living polymers. The electron-withdrawing substituents are N,N-dialkylamide(1), N-alkylimino(2), oxazoline(3), tert-butyl ester(4), N,N-dialkylsulfonamide(5) and cyano(6) moieties. The polymers obtained have predictable molecular weights and narrow molecular weight distributions. The respective postpolymerizations proceeded with quantitative efficiency indicating that each polymer chain end retained the propagating reactivity. However, the resulting living polymers could not initiate the polymerizations of styrene and isoprene. On the other hand, the styrene derivatives(5 and 6) were polymerized with weak nucleophilic initiators, such as living polymer of tert-butyl methacrylate. These results suggest that the electron-withdrawing groups stabilize the living ends and also activate the respective monomers for anionic polymerization. The substitution effect reflects on the ¹³C NMR chemical shift of β-carbon of each vinyl group. The signal of the β-carbon appeared at lower magnetic field than that of styrene indicating electron deficiency on the carbon-carbon double bond of these monomers.     

Synthesis and Characterization of pH‐sensitive Poly(IA‐co‐AAc‐co‐AAm) Hydrogels via Frontal Polymerization

In this work, we report a series of poly(itaconic acid‐co‐acrylic acid‐co‐acrylamide) (poly(IA‐co‐AAc‐co‐AAm)) hydrogels via frontal polymerization (FP). FP starts on the top of the reaction mixture with aid of heating provided from soldering iron gun. Once polymerization initiated, no further energy is required to complete the process. The influences of IA/AAc weight ratios on frontal velocities, temperatures, and conversions on the reaction time are thoroughly investigated and discussed where the amount of AAm monomer remains constant. Fourier transform‐infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), dynamic mechanical analysis, and the swelling measurement are applied to characterize the as‐synthesized poly(IA‐co‐AAc‐co‐AAm) hydrogels. Interestingly, the swelling ratios of the hydrogels are changed with different IA/AAc contents, and the maximum swelling ratios are ~4439% in water. SEM images describe highly porous morphologies and explain good swelling capabilities. Moreover, the poly(IA‐co‐AAc‐co‐AAm) hydrogels exhibit superior pH‐responsive ability. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2214–2221     

Effect of chemical structure on the properties of some hydrogels prepared by using gamma radiation polymerization

Several hydrogels were prepared using radiolytic polymerization of aqueous solutions of acrylamide or acrylamide containing appropriate comonomer such as acrylic acid, maleic acid, itaconic acid, and maleic anhydride. The hydrogels have been prepared at an irradiation dose of 30 kGy. The effects of the chemical structure of the monomer(s) and crosslinking agents on the yield of homopolymer(s) or copolymers have been studied. These crosslinking agents include N, N′‐methylene dimethacrylate (MDA) and N, N′‐methylene bisallyamide (MBA). The hydrogels obtained were characterized using swelling technique, thermal and spectroscopic analysis. The results obtained showed that the prepared samples are able to reject sodium ions and are not able to recover the Basic Blue Dye from their aqueous solution. © 2005 John Wiley & Sons, Ltd.     

Synthesis and water sorption studies of pH sensitive poly(acrylamide-co-itaconic acid) hydrogels

Superabsorbent copolymers of acrylamide (Am) and itaconic acid (ItA) were prepared by free radical solution polymerization using sodium persulfate and N,N,N′,N′-tetramethylenediamine (TMEDA) as initiating system at 35 °C. Two series were prepared. The first series (SA series) used varied amount of itaconic acid and fixed amount of N,N′-methylenebisacrylamide (MBAm), while in the second series (SB series) the amount of (MBAM) changed and the amount of itaconic acid was fixed. The swelling behavior was studied at room temperature and the swelling percentage, swelling kinetics parameters such as initial swelling rate, swelling rate constant, and diffusion parameters were determined. The effect of pH and saline sensitivity on swelling behavior was also studied.     

Influence of gel composition on the solubility parameter of poly(2‐hydroxyethyl methacrylate‐itaconic acid) hydrogels

The solubility parameters of pure poly(2‐hydroxyethyl methacrylate) (PHEMA) and poly(2‐hydroxyethyl methacrylate/itaconic acid) [P(HEMA/IA)] hydrogels were determined by 20 solvents with various solubility parameters in swelling experiments. The solubility parameter of pure PHEMA was 26.93 ± 0.46 (MPa)^1/2. The effect of mole percentages of itaconic acid (IA) in P(HEMA/IA) hydrogels on the solubility parameter was investigated. The measured values were compared to literature and solubility values theoretically determined by group contribution values of van Krevelen and Hoy. The incorporation of IA into the hydrogel system slightly increased the solubility parameter. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1995–2003, 2002     

Radical polymerization of N-substituted itaconamic esters and itaconamides

Two kinds of itaconamic esters, α-substituted acrylate derivatives (IAE-I) and α-substituted acrylamide derivatives (IAE-II), as well as itaconamides (IAm) were prepared and polymerized with a radical initiator. It has been revealed that N,N-disubstituted IAE-I as an acrylate is more reactive in polymerization than N,N-disubstituted IAE-II as an acrylamide and that N,N′-dialkyl substituted IAm homopolymerizes but N,N,N′,N′;-tetraalkyl substituted one does not. In radical copolymerization with styrene, IAE-I showed a higher polymerization reactivity than IAE-II. The effects of the N-substituents on the polymerization reactivity were discussed on the basis of conformation of the monomers. The polymers obtained were also characterized. © 1994 John Wiley & Sons, Inc.     

Ring‐opening metathesis polymerization of amino acid‐functionalized norbornene derivatives

Amino acid‐derived novel norbornene derivatives, N,N′‐(endo‐bicyclo[2.2.1] hept‐5‐en‐2,3‐diyldicarbonyl) bis‐L ‐alanine methyl ester (NBA), N,N′‐(endo‐bicyclo[2.2.1]hept‐5‐en‐2,3‐diyldicarbonyl) bis‐L ‐leucine methyl ester (NBL), N,N′‐(endo‐bicyclo[2.2.1]hept‐5‐en‐2,3‐diyldicarbonyl) bis‐L ‐phenylalanine methyl ester (NBF) were synthesized and polymerized using the Grubbs 2nd generation ruthenium (Ru) catalyst. Although NBA, NBL, and NBF did not undergo homopolymerization, they underwent copolymerization with norbornene (NB) to give the copolymers with M_n ranging from 5200 to 38,100. The maximum incorporation ratio of the amino acid‐based unit was 9%, and the cis contents of the main chain were 54–66%. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5337–5343, 2006     

Synthesis and network structure of ionic poly(N,N-dimethylacrylamide-co-acrylamide) hydrogels: Comparison of swelling degree with theory

At four different charge densities, ionic hydrogels based on N,N-dimethylacrylamide (DMAAm), acrylamide (AAm), and itaconic acid (IA) were synthesized by free-radical cross-linking copolymerization in water with N,N-methylenebis(acrylamide) (BAAm) as the cross-linker, ammonium persulfate (APS) as the initiator, and N,N,N′,N′-tetramethylenediamine (TEMED) as the activator. The swelling behaviors of these hydrogels were analyzed in buffer solutions at various pH. It was observed that the swelling behavior of cross-linked ionic poly(N,N-dimethylacrylamide-co-acrylamide) [P(DMAAm-co-AAm)] hydrogels at different pHs agreed with the modified Flory-Rehner equation based both on the phantom network and affine network models and the ideal Donnan theory. In addition, the kinetics of swelling of the hydrogels was studied in pH 2, 5 and 9 buffer solutions. The swelling curves exhibited the characteristic features of transport process, apparently the Fickian diffusion of fast rates.