Preparation of aqueous soluble polyamides from renewable succinic acid and citric acid as a new approach to design bio‐inspired polymers

A novel type of aqueous soluble polyamides were prepared as renewable substitutes for ecologically benign poly(aspartic acid) by polymerization of succinic acid ester and hexamethylene diamine in the presence of citric acid ester. The copolymerization resulted in the formation of poly(amide imide) intermediates, which were hydrolyzed to aqueous solutions of polyamides. The hydrolyzed products were confirmed to be copolymers of succinamide and citramide with COOH side chains, similar to poly(aspartic acid). The polyamides showed strong chelating abilities to Ca²⁺ and Pb²⁺ metals, comparable to poly(aspartic acid). Interestingly, they also demonstrated antifreeze activities in water by reducing the ice fractions. The polyamides represent a new class of metal chelators and antifreeze protein mimics derived from succinamide and citramide. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39807.     

Synthesis and characterization of new polyamides containing p‐phenylenediacryloyl moieties in the main chain

Six new polyamides 8a–f containing p‐phenylenediacryloyl moieties in the main chain were prepared by the direct polycondensation reaction of bis(p‐amidobenzoic acid)‐p‐phenylene diacrylic acid 6 with 1,4‐diphenylene diamine 7a , 1,3‐diamino toluene 7b , 1,5‐diamino naphthalene 7c , 4,4′‐diamino diphenyl ether 7d , 4,4′‐diamino diphenyl sulfone 7e , and 3,3′‐diamino diphenylsulfone 7f by using thionyl chloride, N‐methyl‐2‐pyrolidone, and pyridine as condensing agents. These new polymers 8a–f were obtained in high yield and inherent viscosity between 0.35–0.65 dL/g. The resulting polyamides were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test, FTIR and UV–vis spectroscopy. Diacid acid 6 as a new monomer containing p‐phenylenediacryloyl moiety was synthesized by using a three‐step reaction. First, p‐phenylenediacrylic acid 3 was prepared by reaction of terephthal aldehyde 1 with malonic acid 2 in the presence of pyridine, then diacid 3 was converted to p‐phenylenediacryloyl chloride 4 by reaction with thionyl chloride. Finally, bis(p‐amidobenzoic acid)‐p‐phenylene diacrylic acid 6 was prepared by the condensation reaction of phenylenediacryloyl chloride 4 with p‐aminobenzoic acid 5 . © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of new polyamides derived from 4‐(4′‐aminophenyl)urazole and aliphatic diacid chlorides

4‐(4′‐Aminophenyl)urazole (AmPU) was prepared from 4‐nitrobenzoic acid in six steps. The reaction of AmPU with acetyl chloride was performed in N,N‐dimethylacetamide solutions at different ratios, and the resulting disubstituted and trisubstituted amide derivatives were obtained in high yields and were used as models for polymerization reactions. Polycondensation reactions of AmPU with succinyl chloride, suberoyl chloride, and sebacoyl chloride were performed with conventional solution polymerization techniques in the presence of different catalysts, such as pyridine, triethylamine, and dibutyltin dilaurate, and led to the formation of novel aliphatic polyamides. The resulting novel polyamides had inherent viscosities of 0.11–0.22 dL/g in dimethylformamide or H₂SO₄ at 25°C. These polyamides were characterized with IR, ¹H‐NMR, elemental analysis, and thermogravimetric analysis. Some physical properties and structural characterization of these novel polyamides are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3173–3185, 2004     

Preparation of thermally stable and optically active organosoluble aromatic polyamides containing <Emphasis Type="SmallCaps">l</Emphasis>-leucine amino acid under green conditions

An optically active bulky dicarboxylic acid (2S)-4-[(4-methyl-2-phthalimidylpentanoylamino)benzoylamino]isophthalic acid (1), was synthesized in five step starting from l-leucine and phthalic anhydride. A set of new aromatic polyamides containing (N-phthaloyl-l-leucine) units was synthesized by the direct one-pot phosphorylation polycondensation of diacid 1 with various aromatic diamines in the presence of different imidazolium salts and triphenyl phosphite (TPP) without adding extra compounds (Method I). This method was compared with a classical method in a medium consisting of TPP, N-methyl-2-pyrrolidinone, pyridine, and calcium chloride (Method II) and the results are comparable. The polymers were produced with high yields and from moderate to high inherent viscosities (0.43–0.81 dL g⁻¹). Amino acid existence in this backbone results in optically active polymers. The chemical structures of some of these polymers were characterized by ¹H-NMR and elemental analysis, and all of them with FT-IR and specific rotation tools. By introduction of bulky and flexible clusters in these new polyamides pendent group; make them soluble in most polar aprotic solvents.     

Direct Polyamidation in Molten Tetrabutylammonium bromide: Novel and Efficient Green Media

This is the first report of application of molten ionic liquid (MIL) for the synthesis of polyamides (PAs) from the reaction of dicarboxylic acids with diisocyanates. A fairly inexpensive and readily accessible MIL, tetrabutylammonium bromide (TBAB) was used for the synthesis of polymers. Therefore, polycondensation of terephthalic acid with various commercially available diisocyanates was performed in molten TBAB with or without dibutyltin dilaurate (DBTDL) as a catalyst. The polymerization reaction gave similar results in the presence or absence of DBTDL, indicating that, the catalyst was not needed in this process. Various PAs were obtained with high yields and moderate inherent viscosities ranging from 0.36 to 0.71 dL/g. This method was compared with the polymerization reaction in conventional solvent and in the presence of DBTDL as a catalyst. In the case of using TBAB, higher yields and inherent viscosities were obtained. This process is safe and green since toxic and volatile organic solvent such as N-methylpyrrolidone (NMP) was eliminated.     

Polyaramides containing arylene sulfone ether linkages

Polyamides containing arylene sulfone ether linkages were synthesized from 4,4′[sulfonybis (p-phenyleneoxy)] dibenzoyl chloride (SPCI), 3,3′-[sulfonylbis (p-phenyleneoxy)] dibenzoyl chloride (SMCl) and various aromatic diamines (ARD), by solution and interfacial polymerization techniques. In solution polymerization, the effect of various acid acceptors such as propylene oxide (PO), lithium hydroxide (LiOH) in the presence of lithium chloride (LiCl), and triethylamine (TEA) on teh molecular weight of the olyamides was studied. The effect of structure of studied. The effect of structur of various aromatic diamine sof molecular weight and thermal properties of polyamides was also studied. The polyamides prepared were characterized by solution viscosity, elemental analysis thermo-gravimetric analysis, differential scanning calorimetry, and x-ray diffraction. Physical and thermal properties of polyamides prepared from SPcl and Ard were compared with the polyamides prepared from SMCl and ARD.     

Synthesis and properties of novel aromatic polyamides derived from 2,2‐bis[4‐(4‐amino‐2‐fluorophenoxy) phenyl]hexafluoropropane and aromatic dicarboxylic acids

A series of polyamides were synthesized by the direct polycondensation of 2,2‐bis[4‐(4‐amino‐2‐fluorophenoxy)phenyl]hexafluoropropane with various commercially available dicarboxylic acids such as terephthalic acid, isophthalic acid, 5‐t‐butyl isophthalic acid, and 2,6‐naphthalene dicarboxylic acid. The synthesized polyamides were soluble in several organic solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, and chloroform, and they exhibited inherent viscosities of 0.42–0.59 dL/g. The polyamides exhibited weight‐average molecular weights of up to 26,000, which depended on the exact repeating unit structure. These polyamides showed good thermal stability up to 440°C for a 10% weight loss in synthetic air. The polyamides synthesized from 5‐t‐butyl isophthalic acid and isophthalic acid exhibited glass‐transition temperatures of 217 and 185°C, respectively (by differential scanning calorimetry) in nitrogen. The polyamides synthesized from terephthalic acid and 2,6‐naphthalene dicarboxylic acid showed melting temperatures of 319 and 385°C, respectively. The polyamides films were pale yellow, with tensile strengths of up to 82 MPa, moduli of elasticity of up to 2.3 GPa, and elongations at break of up to 9%, which depended on the exact repeating unit structure. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 691–696, 2003     

Preparation and characterization of new photoactive polyamides containing 4‐(4‐dimethylaminophenyl)urazole units

4‐(4‐dimethylaminophenyl)‐1,2,4‐triazolidine‐3,5‐dione ( DAPTD ) was prepared from 4‐dimethylaminobenzoic acid in five steps. The compound DAPTD was reacted with excess acetyl chloride in N,N‐dimethylacetamide (DMAc) solution and gave 1,2‐bisacetyl‐4‐[4‐(dimethylaminophenyl)]‐1,2,4‐triazolidine‐3,5‐dione as a model compound. Solution polycondensation reactions of monomer with succinyl chloride (SucC), suberoyl chloride (SubC), and sebacoyl chloride (SebC) were performed under conventional solution polymerization techniques in the presence of triethylamine and pyridine as a catalyst in N‐methylpyrrolidone (NMP) and led to the formation of novel aliphatic polyamides. These novel polyamides have inherent viscosities in the range of 0.09–0.21 dL/g in N,N‐dimethylformamide (DMF) at 25°C. Fluorimetric studies of the model compound as well as polymers were performed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 947–954, 2007     

Synthesis and characterization of polyamides based on natural monomers: l-lysine and l-aspartic acid

Nonpeptidic diamine-diacid type polyamides were prepared from natural α-amino acids, l-lysine and l-aspartic acid, under mild conditions. l-lysine carboxylic group was protected as a benzyl ester; l-aspartic acid amino group was protected as benzyloxycarbonyl (Z) or t-butyloxycarbonyl (BOC) derivatives. The activated ester method provided polyamides with protected amino and carboxyl side groups. The deprotection of these side groups revealed to be perfectly selective when the amino groups were protected as t-butyloxycarbonyl derivatives. Received: 20 February 1997/Revised: 8 April 1997/Accepted: 14 April 1997     

Glycoconjugated polymer 6. Synthesis of poly[styrene-<Emphasis Type="Italic">block</Emphasis>-(styrene-<Emphasis Type="Italic">graft</Emphasis>-amylose)] via potato phosphorylase-catalyzed polymerization

Summary The potato phosphorylase-catalyzed polymerization of α-D-glucose-1-phosphate (G-1-P) onto poly[styrene-block-(4-vinylbenzyl maltohexaoside)] (1) was performed at the molar ratios of [G-l-P]₀ and [maltohexaose]₀ of 35, 80, and 250. The product was found to be soluble in dimethyl sulfoxide, which was a good solvent for amylose, and showed the complex-formation with iodine, indicating that the product was assignable to poly[styrene-block-(styrene-graft-amylose)] (2). The quantitative analysis of the liberated phosphoric acid gave the average degree of polymerization o f the glucose unit (n) as 27, 5 1, and 180 for 2-I, 2-II, and 2-III, respectively. Received: 29 November 2002/Accepted: 22 December 2002 Correspondence to Toyoji Kakuchi     

Synthesis and characterization of aromatic polyamides derived from various derivatives of 4,4’-oxydianiline

Three aromatic diamines, 2,2′-diiodo-4,4′-oxydianiline (DI-ODA 2), 2,2′-bis[p-(trifluoromethyl)phenyl]-4,4′-oxydianiline (BTFP-ODA 3) and 2,8-diaminodibenzofuran (DADBF 5) were synthesized by using 4,4-oxydianiline (4,4′-ODA) as the starting material. New aromatic polyamides 6, 7 and 8 were prepared from these three diamines and six commercially available aromatic diacids by direct polycondensation, respectively. Polyamides 6 and 7 contained bulky iodide and p-trifluoromethylphenyl substitutents that would hinder the chain packing and increase the free volume. They exhibited good optical transparency in visible light region and showed excellent solubility in organic solvents such as DMSO, DMAc, DMF and NMP. Polyamides 8 containing planar dibenzofuran moieties had the highest glass transition temperatures and decomposition temperatures among these polyamides. Polyamides 6 had the lowest decomposition temperatures due to the presence of weak carbon–iodine bond. All of these polyamides showed amorphous nature evidenced by wide angle X-ray diffraction. No endothermic peaks were observed from DSC thermograms up to their decomposition temperatures. High optical transparency and excellent solubility combined with good thermal stability make these polyamides attractive for potential soft electronics applications.     

Water-soluble polyamides as potential drug carriers,VII. Synthesis of polymers containing intrachain- or extrachain-type amine ligands by interfacial polymerization

Aliphatic polyamides comprising poly(ethylene oxide) chain segments of various lengths, designed for use as drug carriers, are synthesized by interfacial polymerization of succinyl chloride with the two Jeffamine types ED-900 and ED-2001, formally described by the supplier as O,O'-bis(2-aminopropyl)poly(ethylene glycol) 800 and O,O'-bis(2-aminopropyl)poly(ethylene glycol) 1900. Copolyamides comprising both short-chain diamine and Jeffamine segments are similarly prepared, as are polyamides made up of cystine and diamine segments. The polymerizations are performed in a two-phase methylene chloride-water system at temperatures near or below 0°C. The product polymers, crudely fractionated by staged aqueous-phase dialysis at an ultimate molecular-mass cut-off of 25000, are collected after freeze-drying as water-soluble resins or solids and are characterized microanalytically and by ¹H NMR spectroscopy. Inherent viscosities are in the range of 10–20 ml g^?1. The drug-binding potential of a representative target polymer is probed by the covalent anchoring of a ferrocene compound used as a drug model, giving a water-soluble polymer-ferrocene conjugate.     

Synthesis and characterization of polyamide resins from soy-based dimer acids and different amides

A series of soy-based polyamides with different dimer acids and diamines were synthesized using a condensation polymerization technique. The molecular weight of polyamides prepared from 1,4-phenylenediamine increases greatly with a reaction temperature above 260°C. The physical properties of the polyamides, such as glass transition temperature (T_g), melting point (T_m), decomposition temperature (T_d), crystalline behavior, and mechanical strength strongly depend on their molecular weight and flexibility of diamines used. The aromatic-based polyamides have a higher T_g, T_m, T_d, and stronger mechanical strength than that of aliphatic-based polyamides. X-ray diffraction patterns of the samples indicate that all of the resins synthesized present a typical semicrystalline morphology. Polyamides made from hydrogenated dimer acid possess lower T_g and higher mechanical strength, compared with polyamides from unsaturated dimer acid with different dimer and trimer ratios. These results are analyzed and discussed in accordance with the influence of rigid aromatic segments and the microstructure of different dimer acids. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68:305–314, 1998     

Synthesis of novel polymeric HALS stabilizers and chain transfer effect of hindered amine norbornene derivatives on ring-opening metathesis polymerization

Cyclooctadiene (COD) was polymerized via ring-opening metathesis polymerization (ROMP) in the presence of 5-norbornene-exo, endo-2-carboxylic acid 2,2,6,6-tetramethyl-4-piperidinyl ester (PN) or 5-norbornene-2-exo-3-endo-dicarboxylic acid bis(2,2,6,6-tetramethyl-4-piperidinyl) ester (2,3-PN) to prepare a new kind of polymeric hindered amine (HALS) stabilizers. Unexpectedly, hindered amine norbornene derivatives PN and 2,3-PN did not act as comonomer but acted as chain transfer agent (CTA). The resulting polymers were characterized by gel permeation chromatography (GPC) and ¹H-NMR. Investigation of polymerization behavior showed that hindered amine groups were introduced into polymer chain by virtue of chain degradation resulted from chain transfer. The molecular weight (M _n) and HALS content of the resulting polymeric HALS stabilizer could be regulated by varying molar ratio of initial monomer to catalyst.     

Synthesis and characterization of polyamides X 18

Step heating melt polycondensation was adopted in the preparation of polyamides based on 1,16‐octadecane diacid and α,ω? (CH₂)_2n diamines (n = 1–6). The structure was confirmed by various spectroscopic techniques (IR, Raman, ¹H‐NMR, and ¹³C‐NMR). High molecular masses were obtained only in the presence of an excess of diamine and when the diamine possessed low volatility. The molecular masses were between (0.94 and 2.1) × 10⁴ Da for all polyamides under consideration. An excellent correlation between size exclusion chromatography and ¹H‐NMR data was demonstrated in the measurement of the degree of polymerization. The melting temperatures of the polyamides decreased from polyamide 12 18 to polyamide 2 18 as the amide density along the molecular chain declined. No significant variation was observed in the glass‐transition and decomposition temperatures of the polyamides that were obtained. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1565–1571, 2005     

Degradable inorganic/polymer core-shell microspheres for pH-triggered release of indole-3-acetic acid

Abstract

The narrowly dispersed functional silica/poly(di(metacryloylooxy-1-ethoxy) methane-co-acryl amide) (SiO₂/P(DMOEM-co-AAm)) core-shell microspheres were synthesized by distillation precipitation polymerization of DMOEM as a degradable crosslinker and AAm as a functional monomer with the presence of 3-(methacryloxy)propyltrimethoxysilane (MPS) modified silica microspheres as seeds. Indole-3-acetic acid (IAA) can be efficiently loaded into the microspheres with a loading capacity of 37.5% via hydrogen-bonding interaction between the carboxylic acid group of IAA and the amide groups on the surface of SiO₂/P(DMOEM-co-AAm). The loaded IAA can be triggered released by pH due to the presence of pH-responsive crosslinker (DMOEM).     

Synthesis of high performance polyamides utilizing copper‐catalyzed amidation of a dibromoarene with different diamides

A series of diphenylquinoxaline‐containing polyamides were prepared from the condensation polymerization of 2,3‐bis (4‐bromophenyl) quinoxaline (DBQ) with various primary and secondary diamides via copper‐catalyzed amidation reaction. The polyamides were characterized with FTIR, NMR, GPC, differential scanning calorimeter, and thermo gravimetric analysis, and their solubility and viscosity were measured. The polyamides synthesized here are amorphous and showed relatively good solubility in polar aprotic solvents and demonstrate the ability to form brownish hard films by solvent casting; their inherent viscosities ranged from 49 to 55 mL/g. The average molecular weights of polyamides were in the range of M_w = 11,950–5592 g/mol (MWD = 1.21–1.87). These polyamides had relatively high thermal stability with T_g values up to 276°C, 10% weight loss temperatures (T_10%) in the range of 364–476°C, and char yields at 600°C in N₂ up to 72%. They also exhibit emission in the solid state and in dilute (0.2 g/dL) DMAc solution at 425–484 nm with photoluminescence quantum (?_f) yields in the range of 14–23%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,characterization, and properties of novel aromatic polyamides containing phthalazinone moiety

A unsymmetrical and kink non-coplanar heterocyclic dicarboxylic acid monomer, 4-[4-(4-carboxy phenoxy)-naphthyl]-2-(4-carboxyphenyl)phthalazin-1-one (3) was successfully synthesized with high purity and high yields. A series of novel polyamides containing phthalazinone were prepared from the newly synthesized dicarboxylic acid with various aromatic diamines by means of the phosphorylation polycondensation reaction. Molecular weights of the obtained polyamides were evaluated viscometrically, and the inherent viscosities (η_inh) measured were in the range 0.54–0.69 dL/g. These polyamides were amorphous and readily soluble in many organic solvents, such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimetheylformamide, dimethyl sulfoxide, pyridine, and m-cresol etc., and they could easily be solution-cast into transparent, flexible films with good mechanical properties, with tensile strength ranging from 63.9 to 81.6 MPa and elongation at break from 7.2 to 11.4%. These polymers still kept good thermal stability with high-glass transition temperatures in the range of 283–338 °C, and the decomposition temperature in nitrogen for a 10% weight-loss temperatures in excess of 490 °C, and char yield at 800 °C in nitrogen ranged from 56 to 63%. Furthermore, the polyamides films were essentially colorless; their cut-off wavelengths were between 365 and 379 nm.     

cis-Diaminedichloroplatinum(II) complexes reversibly bound to water-soluble polyaspartamide carriers for chemotherapeutic applications. I. Platinum coordination to preformed, carrier-attached ethylenediamine ligands

Copolyaspartamides3–5, bearing the ethylenediamine (en) ligand as a repetitive side-chain component in addition to various hydrosolubilizing groups, are synthesized from polysuccinimide1 by a two-step aminolytic ring opening reaction. The completely water-soluble polyamides, possessing inherent viscosities of 5–20 ml g^–1, are used as polymeric carriers for the anchoring of the biomedically important diaminedichloroplatinum(II) coordination complex. Conjugate formation is brought about by treatment of the carriers with the tetrachloroplatinate(II) dianion in aqueous solution at pH 6.0 ± 0.5. The resulting, water-soluble conjugates3-Pt-5-Pt, purified by dialysis (12,000–14,000 molecular mass cutoff) and isolated in the solid state by freeze-drying from aqueous solution, possess platinum contents in the typical range of 15–25%. The metal is bound as acis-dichloro-en-Pt(II) complex to the polymer main chain via a short spacer segment incorporating a biofissionable amide link suitable forin vivo release of the complex. The conjugates are of interest as water-soluble macromolecular platinum coordination compounds for potential use in the chemotherapy of cancerous diseases.Presented in part at the XXVII International Conference on Coordination Chemistry, Broadbeach, Australia, 2–7 July 1989, abstract T6.     

Preparation of poly(tert‐butyl acrylate)‐poly(acrylic acid) amphiphilic copolymers via radiation‐induced reversible addition–fragmentation chain transfer mediated polymerization of tert‐butyl acrylate

Poly(tert‐butyl acrylate) (PtBA) is a versatile hydrophobic macromolecule usually preferred in the development of new materials for a host of applications. PtBA homopolymers with well‐defined structure and controlled molecular weight in a wide range were successfully synthesized via radiation‐induced reversible addition–fragmentation chain transfer (RAFT) polymerization in the presence of a trithiocarbonate type RAFT agent. The polymerization of tBA was performed under ⁶⁰Co γ‐irradiation in the presence of 2‐(dodecylthiocarbonothioylthio)‐2‐methylpropionic acid (DDMAT) as the RAFT agent in toluene at room temperature with three [tBA]/[DDMAT] ratios (400, 600 and 1000) and different irradiation times. Radiation‐induced polymerization of tBA displayed controlled free radical polymerization characteristics: a narrow molecular weight distribution (M_w/M_n ~ 1.1), pseudo first order kinetics and controlled molecular weights. The system followed the RAFT polymerization mechanism even at very low amounts of RAFT agent ([tBA]/[DDMAT] = 1000), and molecular weights up to 113 900 with narrow dispersity (Ð =1.06) were obtained. PtBA was further hydrolysed into different amphiphilic PtBA‐co‐poly(acrylic acid) (PAA) copolymers by low (27.5%) and high (77.3%) degrees of hydrolysis. The pH sensitivity of the two copolymers was investigated by dynamic light scattering at pH 2 and pH 9 (above and below the pK_a value of PAA) and their hydrodynamic diameters and zeta potential values were determined. © 2020 Society of Chemical Industry