Dialkyl Itaconates Research Articles

Simple One-Pot Synthesis of Fully Biobased Unsaturated Polyester Resins Based on Itaconic Acid.

For the preparation of fully biobased unsaturated polyester resins (UPRs), the replacement of styrene with alternate nonpetroleum-based monomers turned out to be one of the most challenging tasks. Its complexity lies in the fact that reactive diluents (RD) have to have low viscosity and volatility, good compatibility with prepolymer, and capability to homopolymerize and copolymerize with its unsaturations. In this context, we directed our efforts to develop fully biobased UPRs using the dialkyl itaconates as an alternative to styrene. Therefore, a series of 100% biobased UPRs were prepared from itaconic acid and 1,2-propandiol and diluted by dialkyl itaconates. The resins were characterized by Fourier transform infrared spectroscopy, NMR, volatility, and viscosity measurements, while the cured samples were characterized by dynamic mechanical properties, thermomechanical analysis, thermogravimetric analysis data, and tensile tests. The influence of RD structure on the properties of cured samples was discussed in detail. It was shown that the prepared resins had evaporation rates of dialkyl itaconates of several orders of magnitude less compared to styrene. The cured resins with dimethyl itaconate showed comparable or even better thermal and mechanical properties compared to the one with styrene. This investigation showed that itaconic acid and dialkyl itaconates are promising bioresources for the preparation of fully biobased UPRs for mass consumption.

Modified PAMAM dendrimer with 4-carbomethoxypyrrolidone surface groups-its uptake, efflux, and location in a cell

Traditional amine terminated PAMAM dendrimers may be readily surface engineered by a facile one-pot conversion with dialkyl itaconate esters into 4-carbomethoxypyrrolidone terminated PAMAM (G=0-4) dendrimers. These terminated dendrimers are uniquely characterized by exhibiting blue fluorescence emissions (λexc=370nm, λmaxem=440nm). Thanks to this property they can be directly analyzed by confocal microscopy and flow cytometry without additional fluorescence labeling, treatment of dendrimers with chemicals or adjusting pH. These intrinsically fluorescent dendrimers were shown to be very effective for assessing important biological cell features such as cellular entry, intracellular trafficking/localization and efflux properties. For example, all tested cell lines (e.g., B14, BRL-3A, and mHippoE-18) rapidly accumulated PAMAM-pyrrolidone dendrimer. The BRL-3A cell line exhibited both cytoplasmic and nuclear localization patterns; whereas in B14 cells and mHippoE-18 cells, the blue dendrimer fluorescence could only be detected in intracellular endosome-like structures. The dendrimer was observed to be released from all three cell lines during the first 24h; however, efflux was substantially slower from the B-14 cell line. The highest efflux rate was observed for the mHippoE-18 cells. This first successful biological experiment opens a broad spectrum of using these dendrimers as new bioimaging agents for extensive biological cell characterizations.

Pendant Chain Effect on the Synthesis, Characterization, and Structure–Property Relations of Poly(di-n-alkyl itaconate-co-isoprene) Biobased Elastomers

A series of biobased elastomers, poly(di-n-alkyl itaconate-co-isoprene)s (PDAIIs), were prepared by using itaconic acid as a renewable starting material. It is revealed that pendent chain profoundly affected the structure and properties of PDAIIs. The molecular structures of the PDAIIs were analyzed by 1H NMR and FTIR. Dialkyl itaconate to isoprene reactivity ratios measured by Kelen–Tudos method demonstrated that PDAIIs with short side chains tended to alternate copolymerized and the long side chain ones tented to gradient copolymerized. Glass transition temperature, dielectric properties, and thermal stability of the PDAIIs were studied and these properties were tunable by varying the side chain length. Tensile tests revealed that cross-linked PDAIIs are elastic with a high elongation at break. With renewable resources and the side chain adjustability, PDAII elastomers potentially have a positive economic and ecological impact.

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

AbstractTemperature‐ 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 Tgs. In the case of NIPAAm/IA and NIPAAm/MMeI copolymers, the presence of the carboxyl groups forming hydrogen bonds increased the Tg, while the monoalkyl and dialkyl itaconates such as MBuI, MOcI, MCeI and DMI lead to a decrease in Tg 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.

Nanophase-separated regions and side-chain relaxation in dialkyl itaconate copolymers

SAXS data for two dialkyl itaconate copolymer series are presented, showing that two characteristic nanophase-separated domains occur when the side-chain lengths are sufficiently different, and provides support for the model of independent side-chain relaxation in these polymers.

13C NMR and electron spin resonance analyses of the radical polymerization of diisopropyl itaconate

AbstractRadical polymerizations of dialkyl itaconates were performed in benzene at 50 °C. The 13C NMR spectra of the obtained polymers indicated that intramolecular chain‐transfer reaction had taken place more frequently in the polymerizations of itaconates with bulkier ester groups as follows: isopropyl (i‐Pr) > n‐butyl (n‐Bu) ≈ ethyl (Et) > methyl (Me). In addition to the 13C NMR analysis, an electron spin resonance (ESR) analysis was conducted for polymerizations of diisopropyl itaconate, the ESR spectra of which consisted of two kinds of resonances due to the radicals with different conformations. It was assumed that the difference in conformation was attributable to the stereosequences near the propagating chain end because the relative intensity ratios of the resonances varied with the magnitude of the intramolecular chain‐transfer reaction, which was accompanied by a decrease in the syndiotacticity of the obtained poly(diisopropyl itaconate)s. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4513–4522, 2002

ESR study of the radicals obtained from adducts of dialkyl itaconates with bromotrichloromethane

Three kinds of bromides were prepared from the reaction of dialkyl itaconates with bromotrichloromethane as precursors of analogous radicals for the propagating radicals of some dialkyl itaconates, i.e., the methyl, deuterated methyl, and adamantyl ester derivatives. The radicals were generated by photoirradiation of a toluene solution of the bromides in the presence of hexabutylditin at -60 to 60°C, and ESR spectra were recorded. Hyperfine splitting and the temperature dependence of the linewidth were determined. The β-deuterated radicals were also characterized to determine a coupling to β-hydrogens.

ESR study of the radicals obtained from adducts of dialkyl itaconates with bromotrichloromethane

Three kinds of bromides were prepared from the reaction of dialkyl itaconates with bromotrichloromethane as precursors of analogous radicals for the propagating radicals of some dialkyl itaconates, i.e., the methyl, deuterated methyl, and adamantyl ester derivatives. The radicals were generated by photoirradiation of a toluene solution of the bromides in the presence of hexabutylditin at −60 to 60°C, and ESR spectra were recorded. Hyperfine splitting and the temperature dependence of the linewidth were determined. The β-deuterated radicals were also characterized to determine a coupling to β-hydrogens. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1969–1978, 1999

Heck Reaction: Stereo Selective Synthesis of Trisubstituted Olefins: Useful Intermediates for Anthraquinone Carboxylic Acid Derivatives

Palladium catalyzed arylation of dialkyl itaconate in presence of Pd(OAc)2/PPh3 as a catalyst, afforded trisubstituted olefins stereo selectively. These alkenes are useful intermediates for the synthesis of anthraquinone carboxylic acid derivatives. A new coumarin is also synthesized using this protocol.

Synthesis, Reactivity Ratios, and Solution Behavior of Vinylpyrrolidone-co-Monoalkyl Itaconate and Vinylpyrrolidone-co-Dialkyl Itaconate Copolymers

Copolymers containing vinylpyrrolidone and mono and dialkyl itaconate units with different length in the side chains were synthesized and characterized. Copolymers of vinylpyrrolidone with three different compositions of monomethyl, monoethyl, monopropyl, monoamyl, dimethyl, diethyl, dipropyl, and diamyl itaconate were obtained by radical polymerization. The reactivity ratios was estimated by using the classical Fineman−Ross and Kelen Tüdos procedures. These parameters were also estimated using a computer program based on nonlinear minimization algorithm, starting from the values of r1 and r2 obtained by the linear procedures. The copolymers can be considered as random. Fractionation of the copolymers were achieved by fractional precipitation. Fractions were characterized by viscometry and light scattering measurements. The unperturbed dimensions were determined using the Stockmayer−Fixman method. Higher rigidity indexes and characteristic ratios are observed in copolymers containing diitaconate units than that with monoitaconate moieties. The dependence of the glass transition temperature Tg with copolymer composition and its correlation with the chain stiffness is also analyzed.

Propagation and termination rate constants of dialkyl itaconates bearing cyclohexyl-based ester groups in radical polymerization

Radical polymerization of dialkyl itaconates bearing cyclohexyl-based ester alkyl groups was examined kinetically. The propagation and termination rate constants were determined during the polymerization with dimethyl 2,2′-azobisisobutyrate in benzene at 60 ° by electron spin resonance spectroscopy. It was confirmed that the large kinetic orders with respect to the monomer in these polymerizations were related to the variable termination rate constant depending on the monomer concentration.

Miscibility of poly( p-vinylphenol) with poly(dialkyl itaconate)s and poly(methoxycarbonylmethyl methacrylate)

The miscibility of poly( p-vinylphenol) (PVPh) with several poly(dialkyl itaconate)s and poly(methoxy-carbonylmethyl methacrylate) (PMOCMA) was studied by d.s.c. and Fourier transform infra-red ( FTi.r.) spectroscopy. Poly(dimethyl itaconate) and a low molecular weight poly(diethyl itaconate) are miscible with four PVPh samples with molecular weights ranging from 1.7 to 30 kg mol −1. A high molecular weight poly(diethyl itaconate) sample is completely miscible with only two PVPh samples with low molecular weights. Poly(di- n-propyl itaconate), poly(di- n-butyl itaconate) and PMOCMA are not completely miscible with PVPh as shown by the presence of two glass transitions in some blends. FTi.r. studies show the existence of hydrogen bonding interactions between PVPh and the carbonyls of −CH 2COOR in poly(dialkyl itaconate)s and the carbonyl of −COOCH 3 in PMOCMA, but the interactions are weaker than the self-association of PVPh.

Blends of Poly(N-vinyl-2-pyrrolidone)/Poly(dialkyl itaconates) and Poly(methacrylates)

Abstract Blends containing poly(N-vinyl-2-pyrrolidone) (PVP) and poly(dialkyl itaconates) (PDI) and poly(methacrylates) (PMA) with different side chain structures were prepared. Polymer blends of various compositions were studied by Differential Scanning Calorimetry (DSC) and Thermomechanical Analysis (TMA). The effect of the substitution on the lateral chain is also analyzed. One Tg value, over the whole range of compositions is observed for the majority of the blends reflecting compatibility. Inmiscible polymer blends are also observed which is apparently dependent on the structure of the side chain.

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

AbstractN‐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.

Effect of .alpha.- and .beta.-ester alkyl groups on the propagation and termination rate constants for radical polymerization of dialkyl itaconates

Radical polymeriiations of seven dialkyl itaconates (DRIs) with methyl, isopropyl, or tert-butyl ester groups were carried out with dimethyl 2,2'-azobis(isobutyrate) in benzene at 60°C. The effects of the α- and β-ester alkyl substituents of the DRIs on the polymerization rate (R p ) and the propagation and termination'rate constants (k p and k t ) were examined. For a-substitution R p decreased with increasing bulkiness of the alkyl group, whereas the opposite was observed for β-substitution. ESR data revealed that K p decreases with bulkiness of the α-ester alkyl group in the order methyl> isopropyl> t-butyl

Influence of hydrogen bonding on the formation of one-phase blends in binary mixtures of modified poly(α-methyl styrene) with alkyl acrylate, alkyl methacrylate and di-alkyl itaconate polymers

Two series of poly(α-methyl styrene), PαMS, based copolymers have been synthesized. In the PαMS (I) series the phenyl ring in the α-methyl styrene unit has been modified to varying degrees by the introduction of a methyl carbinol unit, whereas the trifluoro methyl carbinol unit has been used in the PαMS (II) series. These groups are potential hydrogen bond donor sites of differing acidic strength. It has been found that the introduction of these specific interaction sites allows the formation of one-phase blends with polymers containing an acceptor site, with which unmodified poly(α-methyl styrene) is immiscible. When these acceptor polymers are poly(alkyl acrylate)s and poly(alkyl methacrylate)s then one-phase blends are obtained with the methyl, ethyl and t-butyl derivatives. The range of one-phase blends can be extended to include the n-propyl derivatives if the modified PαMS are mixed with poly(di-alkyl itaconate)s. Glass transition temperatures, T g and lower cloud point (LCP) temperatures have been recorded for all the one-phase blends. The T g values are usually higher than predicted by the simple rule of mixtures and all blends then phase separate on raising the temperature well above T g. These observations, and the differences in phase equilibrium behaviour exhibited amongst the various blends, are discussed in relation to steric restrictions to hydrogen bond formation, and the effect of both the number and strength of the hydrogen bonds formed on the phase stability of the blends.

Radical polymerization reactivity of dialkyl itaconates and characterization of their polymers

Radical polymerizations and copolymerizations of dialkyl itaconates (DRI) having the same two ester alkyl groups were carried out in the presence of 2,2 ′-azobisisobutyronitrile as an initiator. The eighteen kinds of DRIs homopolymerized easily to give vinylidene-type polymers having molecular weights of 7000–110,000. The polymerization behaviour of DRIs, consisting of diisopropyl, dicyclohexyl and di-tert-butyl esters, was investigated kinetically. The polymerization reactivities of butyl (Bu) esters were found to be in the order: nBu ≅ iBu > sBu > tBu, contrary to those for dialkyl fumarates (DRF) (nBu ≅ iBu < sBu < tBu). The ESR spectra due to the propagating radical were observed in the radical polymerization of DRIs at 60°, indicating that the bimolecular termination hardly occurs due to the 1,1-disubstituted structure similar to that of DRFs. From the results of radical copolymerizations of DRIs with styrene, the monomer reactivity ratios ( r 1, r 2) and Q, e values for DRIs were determined. The relative reactivities of DRIs were found to be correlated with both polar and steric effects of the ester alkyl groups from the results of Taft's plot. The characterization of poly(DRIs) obtained was also investigated and discussed.

Group contribution method for predicting polymer-polymer miscibility: binary blends of poly(p-vinylphenol) and ester-containing polymers

The ability of the modified Guggenbeim quasichemical (MGQ) group contribution method for predicting polymerpolymer miscibility has been tested in blends composed of poly(p-vinylphenol) (PVPh) and ester-containing polymers (polyacrylates, polymethacrylates, aliphatic polyesters, and ethylen-co-(vinyl acetate) (EVA) copolymers). The model reproduces quite well the experimental miscibility range of these systems and predicts miscibility in the PVPh/poly(dialkyl itaconate) family from poly(dimethyl itaconate) to poly(dioctyl itaconate)

Synthesis and characterization of polymers from itaconic acid derivatives

AbstractSome itaconic acid derivatives were prepared and polymerized, in which itaconic acid (IA), β‐monoalkyl itaconates (mRI), dialkyl itaconates (DRI), N‐substituted itaconamates (IAE), itaconamides (IAm), itaconic anhydride (IAn), N‐alkylitaconimides (RII), and N‐(alkyl‐substituted phenyl)itaconimides (RPhII) are included. The polymerization reactivity was examined, and discussed in relation to the structure of the monomers. The structure and some properties of the resulting polymers were investigated. Some citraconic acid (CA) and mesaconic acid (MA) derivatives were also polymerized, and their reactivities were compared with the corresponding IA derivatives.

Blends of poly(α-methylstyrene- stat-acrylonitrile) with poly(alkyl acrylate)s, poly(alkyl methacrylate)s, poly(di-alkyl itaconate)s and alkyl methacrylate copolymers

The miscibility behaviour of the copolymer poly(α-methylstyrene- stat-acrylonitrile) (MSAN) with poly(alkyl acrylate)s, poly(alkyl methacrylate)s and poly(dialkyl itaconate)s has been investigated, where the alkyl groups were methyl, ethyl, n-propyl and n-butyl. Only in the poly(alkyl methacrylate) series were miscible blends obtained; no miscible systems were found for mixtures of MSAN with the other two sets of polymers. “Miscibility windows” were established for the MSAN-poly(alkyl methacrylate) blends and lower critical solution temperatures were also measured. From a knowledge of the phase boundaries, segmental interaction energy density parameters ( B ij ) were calculated and used to make predictions about various copolymer-copolymer blends based on the appropriate monomers. These predictions were tested for blends of poly(α-methylstyrene- stat-acrylonitrile) and poly(methyl methacrylate- stat-acrylonitrile) and found to be very satisfactory.