Diisopropyl Fumarate Research Articles

Stannyl phosphaketene as a synthon for phosphorus analogues of β-lactams.

The reaction of the stannyl phosphaketene (Nacnac)SnPCO 1 (Nacnac = CH{(CMe)(2,6-iPr2C6H3N)}2) with B(C6F5)3 produced the 1,4-addition product of (Nacnac)SnPCO(B(C6F5)3). However, the corresponding reactions in the presence of dimethyl maleate, diisopropyl fumarate or diethyl-but-2-ynedioate gave [2+2] addition yielding four-membered phosphacycles, ((Nacnac)Sn(MeO2C))CHPC(OB(C6F5)3)CH(CO2Me), [(C6F5)3B)PC(OSn)C(CO2Me)CH(CO2Me)]2, (Nacnac)Sn(iPrO2C)CC(OAl(C6F5)3)P[CH(CO2iPr)CH2(CO2iPr)]CH(CO2iPr), and (Nacnac)SnP (EtO2CCC(CO2Et))CO(B(C6F5)3), respectively. In contrast, the corresponding reaction of phenylacetylene gave the FLP-addition product (Nacnac)SnOC(P)C(Ph)CH(B(C6F5)3). Collectively, this reactivity demonstrates that the stannyl phosphaketene 1 can act as a synthon for P-analogues of β-lactam derivatives.

Dielectric relaxation and glassy dynamics in poly(diisopropyl fumarate) and its copolymers with acrylate segments

Dynamical behavior and glass transitions in copolymers of diisopropyl fumarate (DiPF) with 1-adamantyl acrylate (AdA) or n-butyl acrylate (nBA) are investigated by dielectric relaxation spectroscopy (DRS) to elucidate the effect of structural constraint due to the absence of a CH2 spacer on the dynamics. DRS measurements revealed that the two copolymers exhibit three dynamical processes: α-, β-, and γ-processes. The relaxation time of the β-process can be described by the Vogel-Fulcher-Tammann (VFT) law in addition to the α-process. Hence, two glass transition temperatures, Tg, can be evaluated from α- and β-processes. The AdA and nBA fraction dependence of Tgs is consistent with that obtained by dynamical mechanical analysis. The Vogel temperature of the α-process is nearly equal to that of the β-process for the PDiPF homopolymer. With the increase in the AdA fraction, the difference in the Vogel temperature between the α- and β-processes increases. This result suggested that there is an intrinsic correlation between the α- and β-processes for PDiPF, and the correlation changes with the AdA fraction. From the nBA fraction dependence of the β-process, the β-process of PDiPF can be related to the segmental motion of the main chain. Nevertheless, PDiPF exhibits a solid-like property up to the Tg, which is related to the α-process. The physical origins of other processes also were discussed.

Terpolymer-chitosan membranes as biomaterial.

The present study shows a novel copolymer synthesis, its application in the membrane design and the physicochemical and biological characterization of the biomaterial obtained. Terpolymer starting diisopropyl fumarate (F), vinyl benzoate (V) and 2-hydroxyethyl methacrylate (H) was prepared by thermal radical polymerization. This polymer (FVH) was obtained in several monomer ratios and characterized by spectroscopic and chromatographic methods (FTIR, 1 H-NMR and SEC). The best relationship of F:V:H was 5:4:1, which allows efficient interaction with chitosan through cross-linking with borax to achieve scaffolds for potential biomedical applications. The membranes were obtained by solvent casting and analyzed by scanning electron microscopy (SEM), swelling behavior and mechanical properties. In addition, we studied the possible cytotoxicity and biocompatibility of these materials using a murine macrophage-like cell line (RAW 264.7) and bone marrow mesenchymal progenitor cells (BMPC), respectively, taking into account their intended applications. The results of this study show that the terpolymer obtained and its combination with a natural polymer is a very interesting strategy to obtain a biomaterial with possible applications in regenerative medicine and this could be extended to other structurally related systems.

Relaxation behavior of poly(diisopropyl fumarate) including no methylene spacer in the main chain

Poly(diisopropyl fumarate) (PDiPF) has dynamic mechanical properties different from the relaxation processes of conventional vinyl polymers, due to the absence of a methylene spacer in the main chain. In this study, we investigated the relaxation behavior of PDiPF using dielectric spectroscopy (DS), differential scanning calorimetry (DSC), wide angle X-ray scattering (WAXS), and dynamic mechanical analysis (DMA). We have demonstrated that the β relaxation of PDiPF has unusual characteristics originating from the absence of a methylene spacer; for example, the β relaxation of PDiPF follows the Vogel–Fulcher–Tammann (VFT) equation, causes a clear step in the DSC curve, and enhances the microscopic packing of the polymer chains in the solid state. These β relaxation behaviors of PDiPF reflect the enlarged cooperative rearranging region (CRR).

Facile synthesis of graft copolymers containing rigid poly(dialkyl fumarate) branches by macromonomer method

ABSTRACTGraft copolymers show microphase separated structure as seen in block copolymers and have lower intrinsic viscosity than block copolymers because of a branching structure. Therefore, considering molding processability, especially for polymers containing rigid segments, graft copolymers are useful architectures. In this work, graft copolymers containing rigid poly(diisopropyl fumarate) (PDiPF) branches were synthesized by full free‐radical polymerization process. First, synthesis of PDiPF macromonomers by addition‐fragmentation chain transfer (AFCT) was investigated. 2,2‐Dimethyl‐4‐methylene‐pentanedioic acid dimethyl ester was found to be an efficient AFCT agent for diisopropyl fumarate (DiPF) polymerization because of the suppression of undesired primary radical termination, which significantly took place when common AFCT agent, methyl 2‐(bromomethyl)acrylate, was used. Copolymerization of PDiPF macromonomer with ethyl acrylate accomplished the generation of the graft copolymer having flexible poly(ethyl acrylate) backbone and rigid PDiPF branches. The graft copolymer showed a microphase separated structure, high transparency, and characteristic thermal properties to PDiPF and poly(ethyl acrylate). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2474–2480

Relaxation behavior of random copolymers containing rigid fumarate and flexible acrylate segments by dynamic mechanical analysis

Due to the absence of a methylene spacer in the main chain, poly(substituted methylene)s with rigid structures possess some distinguished properties including a unique β-relaxation process. In this study, two series of random copolymers of diisopropyl fumarate (DiPF) with 1-adamantyl acrylate (AdA) and n-butyl acrylate (nBA) with various compositions were synthesized. The relaxation behavior of the copolymers was investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The α-relaxation temperature of the copolymers decreased as the acrylate content increased. Depending on the glass transition temperature (Tg) of the counterpart copolymers, that is, Tg = 156 °C for the homopolymer of AdA and Tg = –53 °C for the homopolymer of nBA, the β-relaxation temperature from the DiPF segments systematically shifted. While the β-relaxation temperature increased when copolymerized with AdA, the temperature decreased when copolymerized with nBA. Both copolymers maintained a high storage modulus of more than 10 MPa in the range between the α- and β-relaxation temperatures. The merging of the α and β processes at an intermediate composition was also observed. The random copolymerization of DiPF and acrylates enables us to fine tune the properties associated with the β-relaxation of DiPF segments. The relaxation behavior of random copolymers of diisopropyl fumarate (DiPF) with 1-adamantyl acrylate (AdA) and n-butyl acrylate with various compositions was investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The β relaxation temperature systematically shifted depending on the glass transition temperature of the counterpart copolymers, and the merging of the α and β processes at an intermediate composition was also observed. Thus, the random copolymerization of DiPF and acrylates enables us to fine tune the properties associated with the β relaxation of DiPF segments.

Matrices based on lineal and star fumarate-metha/acrylate copolymers for bone tissue engineering: Characterization and biocompatibility studies.

This article presents the preparation of matrices from two new families of fumaric copolymers and the effect of structural differences on their physicochemical and biological behavior. Diisopropyl fumarate (DIPF) and poly(ethylene glycol) methyl ether methacrylate (OEGMA) or N-isopropylacrylamide (NIPAM) were copolymerized by conventional radical and RAFT polymerization to obtain lineal or start architectures, respectively. These copolymers were characterized by spectroscopic (FTIR and 1 H-NMR) and chromatographic methods. The thermal stability was studied by thermal gravimetric analysis, showing some differences in relation to the architecture and chemical nature of copolymers. SEM morphological analysis demonstrated that the surface of the matrices derived from OEGMA exhibited an irregular and rough surface, while DIPF-NIPAM copolymers presented smooth surface with nearly no significant porosity. The matrix obtained of both kinds of copolymers presented no cytotoxicity as it was evaluated using a model of macrophages on culture. Moreover, cell growth was better on the surfaces of the DIPF-NIPAM matrices, suggesting a good interaction with this matrix and its potential application as matrices for tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 195-203, 2019.

Synthesis of transparent block copolymers consisting of poly(diisopropyl fumarate) and poly(2‐ethylhexyl acrylate) segments by reversible addition‐fragmentation chain transfer polymerization using trithiocarbonates as the chain transfer agents

ABSTRACTThe reversible addition‐fragmentation chain transfer polymerization of diisopropyl fumarate (DiPF) was carried out using ethyl 2‐[[(dodecylthio)thioxymethyl]thio]‐2‐methylpropionate (T1) and 1,1′‐(1,2‐ethanediyl) bis[2‐[[(dodecylthio)thioxymethyl]thio]‐2‐methylpropionate] (T2) as the monofunctional and difunctional chain transfer agents (CTAs) to synthesize poly(diisopropyl fumarate) (PDiPF) with a rigid chain conformation. The obtained PDiPF had a well‐controlled molecular weight, molecular weight distribution, and structure of the chain ends. Size exclusion chromatography and NMR measurements revealed an excellent introduction efficiency (84–98%) of the terminal trithiocarbonate group into the polymer chain end. They were available as the monofunctional and difunctional macro‐CTAs to synthesize the AB and ABA block copolymers, respectively. While the well‐controlled block copolymers were solely obtained by the polymerization of 2‐ethylhexyl acrylate as the second monomer in the presence of PDiPF as the macro‐CTA, the block copolymerization of DiPF using poly(2‐ethylhexyl acrylate) as the macro‐CTA failed. The trithiocarbonate group at the chain end was completely removed by the reaction with n‐butylamine and it was valid for the improvement of the coloration and other optical properties of the transparent polymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2584–2594

Reversible addition‐fragmentation chain transfer polymerization of diisopropyl fumarate using various dithiobenzoates as chain transfer agents

ABSTRACTDialkyl fumarates as 1,2‐disubstituted ethylenes exhibit unique features of radical polymerization kinetics due to their significant steric hindrance in propagation and termination processes and provide polymers with a rigid chain structure different from conventional vinyl polymers. In this study, we carried out reversible addition‐fragmentation chain transfer polymerization of diisopropyl fumarate (DiPF) in bulk at 80 °C using various dithiobenzoates with different leaving R groups as chain transfer agents to reveal their performance for control of molecular weight, molecular weight distribution, and chain end functionality of the resulting poly(DiPF) (PDiPF). 2‐(Ethoxycarbonyl)‐2‐propyl dithiobenzoate (DB1) and 2,4,4‐trimethyl‐2‐pentyl dithiobenzoate (DB2) underwent fragmentation and reinitiation at a moderate rate and consequently led to the formation of PDiPF with well‐controlled chain structures. It was confirmed that molecular weight of PDiPF produced by controlled polymerization with DB1 and DB2 agreed with theoretical one and molecular weight distribution was narrow. Dithiobenzoate and R fragments were introduced into the polymer chain ends with high functionality as 95% by the use of DB1. In contrast, polymerizations using 1‐(ethoxycarbonyl)benzyl dithiobenzoate (DB3), 1‐phenylethyl dithiobenzoate (DB4), and 2‐phenyl‐2‐propyl dithiobenzoate (DB5) resulted in poor control of molecular weight, molecular weight distribution, and chain end structures of PDiPF. Fragmentation and reinitiation rates of the used benzoates as chain transfer agents significantly varied depending on the R structures in an opposite fashion; that is, introduction of bulky and conjugating substituents accelerated fragmentation, but it retarded initiation of DiPF polymerization. It was revealed that balance of fragmentation and reinitiation was important for controlled polymerization of DiPF. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3266–3275

UV and γ-ray resistance of poly(N-methylmaleimide-alt-isobutene) and poly(diisopropyl fumarate) as transparent polymer films

UV and γ-ray resistance of transparent polymers obtained by radical polymerization of maleic and fumaric acid derivatives, i.e., an alternating copolymer of N-methylmaleimide and isobutene (PMI) and poly(diisopropyl fumarate) (PDiPF), was investigated. Transmittance in UV and visible regions of these polymers were examined after UV irradiation and compared with the results for poly(methyl methacrylate) (PMMA) and polycarbonate (PC) as conventional transparent polymers. The order of stability toward UV irradiation was PMMA≈PDiPF>PMI>>PC, deduced from changes in the transmittance of 380nm light. Tensile mechanical properties, such as elastic modulus, maximum strength, and elongation values of PMI, PDiPF, and PMMA were also investigated after UV and γ-radiation. UV irradiation induced the side chain scission of PMI and PDiPF via Norrish I type reaction as well as crosslinking by combination between formed polymer radicals, leading to deterioration in their optical and mechanical properties. γ-radiation induced significant changes in molecular weight and mechanical properties of the polymers. In conclusion, PMI exhibited unchanged mechanical properties and PDiPF maintained its high transparency under various irradiation conditions.

Thermal and mechanical properties of random copolymers of diisopropyl fumarate with 1‐adamantyl and bornyl acrylates with high glass transition temperatures

ABSTRACTWe report the thermal, optical, and mechanical properties of random copolymers produced by radical copolymerizations of diisopropyl fumarate (DiPF) with 1‐adamantyl acrylate (AdA) and bornyl acrylate (BoA). The effects of a methylene spacer included in the main chain and bulky ester alkyl groups in the side chain on the copolymer properties are discussed. The produced copolymers are characterized by NMR and UV–vis spectroscopies, size exclusion chromatography, thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis (DMA). The copolymerization rate and the molecular weight of the copolymers increase with an increase in the acrylate content in feed during the copolymerization (Mw = 25–110 × 103). The onset temperature of decomposition (Td5) and the glass transition temperature (Tg) of the copolymers also increase according to the content of the acrylate units (Td5 = 296–329 °C and 281–322 °C, Tg = 80–133 °C and 91–106 °C for the copolymers of DiPF with AdA and BoA, respectively). Transparent and flexible copolymer films are obtained by a casting method and their optical properties such as transparency and refractive indices are investigated (nD = 1.478–1.479). The viscoelastic data of the copolymers are collected by DMA measurements under temperature control. The storage modulus decreases at a temperature region over the Tg value of the copolymers, depending on the structure and amount of the acrylate units. The sequence structure of the copolymers is analyzed based on monomer reactivity ratios and composition in order to discuss the copolymer properties related to chain rigidity and sequence length distribution. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 288–296

Dilute solution properties of poly(di-tert-butyl fumarate)

The mean-square radius of gyration 〈S 2〉 is determined for poly(di-tert-butyl fumarate) (PDtBF) for a range of weight-average number of repeat units n w from 382 to 1520 in tetrahydrofuran at 30.0 °C. The data are analyzed on the basis of the Kratky–Porod (KP) wormlike chain with excluded volume (EV). It is shown that the average chain dimension of PDtBF is significantly larger than that of poly(diisopropyl fumarate) (PDiPF) because of a remarkable difference in chain stiffness between the two polymers.

Living radical polymerization of diisopropyl fumarate to obtain block copolymers containing rigid poly(substituted methylene) and flexible polyacrylate segments

ABSTRACTLiving radical polymerizations of diisopropyl fumarate (DiPF) are carried out to synthesize poly(diisopropyl fumarate) (PDiPF) as a rigid poly(substituted methylene) and its block copolymers combined with a flexible polyacrylate segment. Reversible addition‐fragmentation chain transfer (RAFT) polymerization is suitable to obtain a high‐molecular‐weight PDiPF with well‐controlled molecular weight, molecular weight distribution, and chain‐end structures, while organotellurium‐mediated living radical polymerization (TERP) and reversible chain transfer catalyzed polymerization (RTCP) give PDiPF with controlled chain structures under limited polymerization conditions. In contrast, controlled polymerization for the production of high‐molecular‐weight and well‐defined PDiPF is not achieved by atom transfer radical polymerization (ATRP) and nitroxide‐mediated radical polymerization (NMP). The block copolymers consisting of rigid poly(substituted methylene) and flexible polyacrylate segments are synthesized by the RAFT polymerization. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2136–2147

Thermal characterization of novel p-nitrobenzylacrylate–diisopropyl fumarate copolymer synthesized under microwave energy

Copolymers of p-nitrobenzyl acrylate and diisopropyl fumarate with different feed ratios were synthesized under microwave and thermal heating conditions, and then characterized by IR, 1H-, and 13C-NMR spectroscopy. Average molecular weights were analyzed by size exclusion chromatography (SEC). Monomer reactivity ratios were obtained from an extended Kelen–Tudos method. Differential scanning calorimetry and thermogravimetry were used to evaluate the thermal behavior of all copolymers synthesized under microwave energy. Based on the products analyzed by SEC and gas chromatography–mass spectrometry, a possible mechanism of degradation is postulated.

Novel Copolymer of Diisopropyl Fumarate and Benzyl Acrylate Synthesized Under Microwave Energy and Quasielastic Light Scattering Measurements

Microwave assisted free radical copolymerization of diisopropyl fumarate (DIPF) and benzyl acrylate (BzA) with different copolymer compositions was performed using benzoyl peroxide as initiator. The effect of the reaction conditions on the macromolecular characteristics, monomer reactivity ratio and copolymer properties were studied. The monomer conversion and average molecular weights increase with the content of BzA units in the copolymer. The copolymers were characterized by IR, 1H and 13C-NMR spectroscopies and the molecular weights were analyzed with size exclusion chromatography (SEC). The reactivity ratios obtained from an extended Kelen-Tüdös method under microwave irradiations are a factor which is double than those obtained by thermal copolymerization. The product r1r2 = 0.152 suggests a preference of both propagating macroradicals toward consecutive homopolymerization. The hydrodynamic and polydispersity size were measured in ethylacetate, tetrahydrofuran and methylethylketone with a quasi-elastic light scattering (QELS) technique showing that the quality of the solvents increases in the order: EA < THF < MEK.

Characterization of Poly(ε-caprolactone)/Polyfumarate Blends as Scaffolds for Bone Tissue Engineering

There is considerable interest in the design of polymeric biomaterials that can be used for the repair of bone defects. In this study, we used ultrasound to prepare a compatibilized blend of poly(ε-caprolactone) (PCL) and poly(diisopropyl fumarate) (PDIPF). The formation of post-sonication inter-polymer coupling products was verified by SEC analysis of a blend with azo-labeled PDIPF. We also analyzed the physicochemical and mechanical properties of the compatibilized blend. When compared to PCL alone, the PCL/PDIPF blend showed no difference in its resistance as evaluated by the elastic modulus, although it did show a 50% decrease in ultimate tensile stress (P < 0.05) and an 84% decrease in elongation-at-break (P < 0.05). However, the mechanical properties of this blend were comparable to those of trabecular bone. We next evaluated biocompatibility of the PCL/PDIPF blend, and of homo-polymeric PCL and PDIPF films for comparison, with UMR106 and MC3T3E1 osteoblastic cells. Osteoblasts plated on the compatibilized blend adhered and proliferated more than on either homo-polymer, showed a greater number of cellular processes with a better organized actin cytoskeleton and expressed more type-I collagen and mineral, both markers of osteoblast phenotype. These results support the hypothesis that this new compatibilized blend could be useful in future applications for bone regeneration.

Transport Coefficients of Poly(diisopropyl fumarate) in Dilute Solution

Top of pageAbstract The intrinsic viscosity [η] was determined for 13 samples of poly(diisopropyl fumarate), each with the fraction of racemo diads fr = 0.22, in the range of weight-average molecular weight Mw from 4.02 × 104 to 8.59 × 105 in tetrahydrofuran at 30.0 °C. The translational diffusion coefficient D was also determined from dynamic light scattering measurements for 12 of them in the range of Mw from 4.95 × 104 to 8.59 × 105 under the same solvent condition. The data so obtained were analyzed on the basis of the corresponding transport theories for the unperturbed Kratky–Porod (KP) wormlike cylinder model combined with the quasi-two-parameter theory for the intramolecular excluded–volume effect. It is shown that the experimental values are in quantitative agreement with the perturbed KP theory ones by the use of the model parameter values consistent with those determined previously from analyses of the mean-square radius of gyration (S2) and second virial coefficient A2. An examination was also made of behavior of the Flory–Fox factor Φ and reduced hydrodynamic radius ρ−l as functions of Mw. Keywords: Poly(diisopropyl fumarate), Intrinsic Viscosity, Translational Diffusion Coefficient, Kratky–Porod Wormlike Chain Model, Excluded-Volume Effect, Quasi-Two-Parameter Theory

Mean-Square Radius of Gyration and Second Virial Coefficient of Poly(diisopropyl fumarate) in Dilute Solution

The mean-square radius of gyration <S2> and second virial coefficient A2 were determined from light scattering measurements for 13 samples of poly(diisopropyl fumarate) (PDiPF), each with the fraction of racemo diads fr=0.22, in a range of weight-average molecular weight from 4.02×104 to 8.59×105 in tetrahydrofuran at 30.0 °C. From a simultaneous analysis of the present data for <S2> and A2 on the basis of the Kratky–Porod (KP) wormlike chain with excluded volume, the KP model parameters for PDiPF, i.e., the stiffness parameter λ−1 and the shift factor ML are determined to be 113 Å and 89 Å−1, respectively, the ML value being consistent with that estimated on the basis of chain conformations of PDiPF. The λ−1 value indicates that PDiPF is stiffer than typical flexible polymers but not so stiff as typical semiflexible polymers such as poly(n-hexyl isocyanate).

Molecular orientation in Langmuir–Blodgett films of polyfumarates carrying isopropylester and isopropylamide side chains

Molecular orientation in Langmuir–Blodgett (LB) films of poly(diisopropyl fumarate) (PDiPF) and poly(isopropyl N-isopropyl fumaramate) (PiPFAE), prepared by solution polymerization and emulsifier-free emulsion polymerization, respectively, was investigated. The π– A isotherms of both polymers indicated formation of stable Langmuir monolayers. The refractive index measurements as well as the polarized IR and UV spectroscopy of the LB films revealed that the backbones of the polymers were oriented parallel to the dipping direction of the substrate. The LB films were applied to a nematic liquid crystal alignment film, and the relationship between optical axes of the LB films and the alignment direction of the liquid crystal molecules was characterized. Utilization of PDiPF and PiPFAE as a matrix polymer for polymer dispersed liquid crystals was also examined, and a higher performance with a better contrast ratio was obtained for PiPFAE.

Polymerization of diisopropyl fumarate under microwave irradiation

AbstractDiisopropyl fumarate (DiPF), a representative monomer of dialkyl fumarates, was polymerized by microwave irradiation at three different powers (140, 210, and 280 W), using a domestic microwave oven. The nature and concentration of initiators [2,2′‐azobisisobutyronitrile (AIBN) and benzoyl peroxide (BP)], power and energy of microwave irradiation on the conversion, weight average molecular weight (Mw), and polydispersity index (Mw/Mn) were analyzed. The results indicate that the microwave conditions have a significant nonthermal effect in enhancing the polymerization rate of DiPF. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3785–3791, 2007