New aryloxy-substituted condensation polymers

Large family of new aromatic diamines containing aryloxy side groups was developed. All the diamines were obtained on the basis of 2,4,6-trinitrotoluene (TNT) — very cheap and available explosive material. TNT was converted into 1,3,5-trinitrobenzene (TNB); subsequent aromatic nucleophilic nitro-displacement reactions led to mono- and diaryloxy-substituted mono- and dinitrobenzenes which were converted into the final aryloxy-substituted diamines.

Interaction of the diamines obtained with aromatic dicarboxylic acids chlorides and aromatic tetracarboxylic acids dianhydrides led to the formation of new aryloxy-substituted polyimides and polyimides combining high thermal properties with solubility in organic solvents.     

Soluble rigid rod-like polyimides and polyamides containing curable pendent groups

Soluble rod-like aromatic polyimides and polyamides containing curable pendent groups were synthesized. The polyimides (PIEANs) and polyamides (PAEANs) containing pendent enaminonitrile groups showed good thermal stability, and underwent curing reactions without the emission of volatile by-products above 300 °C to stable materials which were not soluble in any organic solvents. However, the polyimides (PIEONs) and polyamides (PAEONs) containing pendent enoxynitrile groups started to decompose around 300 °C, because of the instability of enoxynitrile groups. PAEONs underwent curing reactions around 420 °C in spite of the initial decomposition, but PIEONs exhibited only thermal degradation process. Thermal analyses of these polymers and the corresponding model compounds revealed that the curing of enaminonitrile groups proceeded via intermolecular crosslinking as well as intramolecular cyclization, while the enoxynitrile groups, known to undergo self-curing reaction, could not be cured by itself, and a reactive amine group was essential for the curing of the enoxynitrile groups.     

Syntheses of functional condensation polymers. II. A polyamide having epoxy groups and its ring-opening derivatives

Polyamides having epoxy groups and their ring-opening derivatives were prepared and characterized, and some of their properties were investigated. Reaction conditions for the low-temperature polycondensation of cis-2,3-epoxysuccinyl chloride (ESC) with aromatic diamines and the interfacial copolycondensation of ESC and adipyl chloride (AC) with aromatic diamines were established to obtain a high molecular weight polyamide having epoxy groups. In addition, the ring-opening reactions of the epoxy groups in the polyamides were carried out with various amines in order to obtain polyamides having hydrophilic pendent groups such as amino and hydroxyl. It was found that the polyamides prepared by ring-opening reaction of the epoxy group with ethylenediamine (EDA) or ethanolamine (EA) had a higher affinity for moisture than those with hexamethylenediamine (HMD) or n-butylamine (n-BA), which might be ascribed to the distance of hydrophilic groups from the polyamide chain. Those polyamides having hydrophilic pendent groups decomposed upon heating at less than 200°C.     

Novel nonlinear optical polymers with crosslinkable functional groups

Summary Monomers with non linear optical (NLO) and photocrosslinkable (cinnamate) active side group have been synthetized. The study of their copolymerization has shown that a third monomer is necessary to increase the yield of copolymerization from 9% to 53%. The monomers reactivity ratios were estimated to be close to each other. Glass transition temperatures are relatively high though inherent viscosities of the terpolymer are low.     

Implementation of ionic liquids as activating media for polycondensation processes

Ionic Liquids (ILs) have been used for polycondensation processes, especially for polyimide synthesis. The influence of various reaction parameters including IL's cations and anions nature, monomer structure and concentration, reaction temperature, upon polyimide molecular weight (η_inh) was investigated. The possibility of process activation by the application of IL's small additives in one step polyimide synthesis in common organic solvents was demonstrated. The peculiarities of C-H?Br contacts in solid state were carried out using single crystal X-ray diffraction data. Various high molecular weight polyimides including commercial and sulfonated ones have been obtained in quantitative yields with inherent viscosities ranging from 0.10 to 2.17 dl g⁻¹.     

Synthesis and properties of organosoluble polyimides based on 2,2′-diphenoxy-4,4′,5,5′-biphenyltetracarboxylic dianhydride

A novel method for the preparation of 2,2′-diphenoxy-4,4′,5,5′-biphenyltetracarboxylic dianhydride have been investigated. This new dianhydride contains flexible phenoxy side chain and a twist biphenyl moiety and it was synthesized by the nitration of an N-methyl protected 3,3′,4,4′-biphenyltetracarboxylic dianhydride and subsequent aromatic nucleophilic substitution with phenoxide. The overall yield was up to 75%. The dianhydride was polymerized with five different aromatic diamines to afford a series of aromatic polyimides. The polyimide properties such as inherent viscosity, solubility, UV transparency and thermaloxidative properties were investigated to illustrate the contribution of the introduction of phenoxy group at 2- and 2′-position of BPDA dianhydride. The resulting polyimides possessed excellent solubility in the fact that the polyimide containing rigid diamines such as 1,4-phenylenediamine and 4,4′-oxydianiline were soluble in various solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide and chloroform. The glass-transition temperatures of the polymers were in the range of 255-283 °C. These polymers exhibited good thermal stability with the temperatures at 5% weight loss range from 470 to 528 °C in nitrogen and 451 to 521 °C in air, respectively. The polyimide films were found to be transparent, flexible, and tough. The films had a tensile strength, elongation at break, and Young's modulus in the ranges 105-168 MPa, 15-51%, 1.87-2.38 GPa, respectively.     

Synthesis and properties evaluation of novel halogenated polyimides designed to prepare functional polymers

Three new aromatic polyimides containing one or two replaceable halogen atoms in the repeat unit have been prepared by one-pot polycondensation at high temperature from dianhydrides and diamines containing halogen atoms. The halogenated polyimides exhibited good thermal properties and great solubility in a wide range of organic solvents, which make them good candidates to prepare functional polymers. They also showed film-forming capabilities, good mechanical properties, and a very low ability to take water, with values of only around 1% water uptake. To show the usefulness of these polyimides as functional polymers, the halogen group of two of them was successfully replaced by 4-tert-butyl phenyl or 4-tert-butyl phenyl ethynyl groups by a Suzuki or a Sonogashira reaction, respectively.     

Reactive carbon black having acyl imidazole or acid anhydride groups: Preparation and reaction with functional polymers having hydroxyl or amino groups

The introduction of acyl imidazole groups onto a carbon black surface was achieved by the reaction of the carboxyl groups on the surface with N N′-carbonyldiimidazole, the loading of acyl imidazole groups introduced was determined to be 0.28 mmol/g. In addition, reactive carbon black having acid anhydride groups was prepared by the reaction of phenolic hydroxyl groups with trimellitic anhydride chloride; the amount of acid anhydride groups introduced onto the surface was determined to be 0.20 mmol/g. The reaction of acyl imidazole groups on carbon black with commercially available polymers having hydroxyl or amino groups such resulted in polymers that were found to be grafted onto the surface via ester or amide bonds. The percentage of grafting of diol-type poly(propylene glycol) and diamine-type polydimethylsiloxane was increased to 27.2 % and 42.5 %, respectively. Furthermore, acid anhydride groups on carbon black also reacted with functional polymers having hydroxyl or amino groups to give polymer-grafted carbon blacks. The grafting reaction was accelerated by the addition of tertiary amines. These polymer-grafted carbon blacks produced a stable colloidal dispersion in good solvents for the grafted polymer, but readily precipitated in poor solvents.     

Novel rapid switching and bleaching electrochromic polyimides containing triarylamine with 2-phenyl-2-isopropyl groups

A series of novel organosoluble polyimides and copolyimides with a propeller-shaped triarylamine unit were prepared from diamine and various aromatic dianhydrides via direct polycondensation. All of the polymers possessed tough, flexible, and strong films with high molecular weights. The polyimide and copolyimide films revealed electrochromic characteristics, with a color change from pale yellowish at its neutral state, to green, and finally to blue at its oxidized state, at applied potentials ranging from 0 to 1.50 V. The polyimide (Ib) film exhibited switching times of 4.5 s at 1.08 V at 424 and 877 nm and 1.9 s for fast bleaching due to a pendent substituted 2-phenyl-2-isopropyl group. Cyclic voltammetry (CV) of the polymer films showed two reversible redox couples at potentials of 0.91-0.99 V and 1.30-1.38 V, respectively. The CV results of the model compound M1 and model polyimide M2, were not a match to the oxidation peaks of polyimide Ib, indicating that the contribution of the oxidation was not only from the electron removal of nitrogen atoms.     

Enantioface differentiation by using soluble chiral polymers having 2,3-exo-bornanediol groups

Soluble linear polymers containing 2,3-exo-dihydroxy-3-endo-p-tolyl-3-bornyl groups prepared by reaction of lithiated linear polystyrenes with (-)-2-exo-hydroxy-3-bornanone, are treated with lithium aluminium hydride to form complexes which can be used as reducing reagents. The highest enantioselectivity compared with those cases using crosslinked polystyrene as carrier and chiral low molecular weight compounds is achieved by linear polystyrene having chiral groups. The advantages of soluble polymer-bound chiral reagents are discussed. The effect of alcohols, the reaction temperature, the sort of solvents, and the molar ratio of the reagent to ketone on the asymmetric reduction is also discussed.     

Novel luminescent polymers containing backbone triphenylamine groups and pendant quinoxaline groups

Novel, conjugated polyfluorene derivatives that comprised an electron-donating triphenylamine group in the backbone and pendant, electron-accepting quinoxaline moieties, were synthesized via the Suzuki coupling reaction and their UV–vis absorption, fluorescence emission and electrochemical properties were investigated. The copolymers were readily soluble in common organic solvents and displayed good film-forming ability and excellent thermal stability. Electroluminescence devices, comprising indium tin oxide/poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonic acid)/emitting polymer/Ba/Al, in which the polymers were employed as emissive layers, exhibited superior performance compared to that of corresponding, poly(9,9-dioctylfluorene) and poly(9,9-dioctylfluorene-co-4,4′-triphenylamine) based devices, indicating that the polymers offer promise as emissive materials in polymeric light-emitting diodes.     

Multicomponent anion exchange with a resin having weakly and strongly basic groups

Multicomponent anion exchange with a resin having both weakly and strongly basic groups was investigated by means of modelling and column experiments. Our objective was to develop a model able to predict the evolution of the composition of a water treated by such a resin. The studied resin was Purolite S108, used for boron removal from water, on which ternary and quaternary amines were attached (additionally to boron complexing groups). Column dynamics were modelled with the computer code IMPACT, devoted to reactive transport in porous media. A reaction scheme was proposed to represent anion exchange on the two types of groups, with a quaternary anionic system including hydroxide, chloride, sulphate and nitrate at a given ionic concentration. This reaction scheme needed eight parameters: concentrations of weak and strong-base groups and the anion exchange selectivities. These parameters were measured through binary anion exchange, without or with pH step. The breakthrough curves of the binary experiments were in very good agreement with the experimental one. The model was then used to predict the results of a more complex experiment in which the column had been fed by a mixture of acids. The main features of the experimental behaviour were fairly well predicted, even if the agreement was not perfect. These discrepancies were attributed to the model assumptions, mainly to the expressions of anion exchange selectivities. These results enabled us to predict almost quantitatively the evolution of the water composition during its treatment. This point is an improvement in the prediction of the dynamics of an anion exchange with two types of groups. In the future, the model would have to be extended to take into account different expressions of the exchange selectivities, and nonequilibrium conditions.     

Soluble polyimides with trifluoromethyl pendent groups

Unsymmetrical and symmetrical diamine monomers containing trifluoromethyl groups, 2-trifluoromethyl-4,4′-diaminodiphenyl sulfide and 2,2′-bis(trifluoromethyl)-4,4′-diamino-diphenyl sulfide, were synthesized from 2-chloro-5-nitrobenzotrifluoride as a starting material in two steps, respectively. Diamine monomers were polymerized with PMDA, BPDA, BTDA, and ODPA using a solution imidization method with N-methyl-2-pyrrolidone as a solvent at 190 °C to obtain the corresponding polyimides. They had inherent viscosities that ranged from 0.54 to 0.71 dL/g in N-methyl-2-pyrrolidone at 30 °C. All of the synthesized polyimides showed good solubility in polar aprotic solvents and phenolic solvents regardless of the number of trifluoromethyl groups. The 5% weight loss temperatures of the polyimides are in the range of 534–561 °C in nitrogen, and 505–542 °C in air. The T_g values and the thermal expansion coefficients of these polymers are in the range of 234–325 °C and in the range of 47.4–63.2 ppm/°C, respectively. Also, all of the synthesized polyimides have relatively low refractive indices (around 1.6) and birefringence (below 0.36).     

Synthesis and characterization of novel aromatic condensation polymers containing rigid benzoxazole pendent groups

A new aromatic diamine monomer containing benzoxazole substituents was prepared by a multistep synthesis starting from 1,4‐dibromo‐2,5‐difluorobenzene. The diamine was polymerized with commercial aromatic dianhydride or dicarboxylic acid chloride monomers to provide several different poly(amic acid)s and polyamides with their inherent viscosities in the range of 0.24–0.46 dL/g. Thermal properties of these polymers including thermal imidization of poly(amic acid)s into polyimides were investigated by using FTIR, DSC, and TGA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 178–185, 2004     

Theory of chromatography of linear and cyclic polymers with functional groups

We discuss the chromatographic behavior of linear polymers and rings having specific (functional) adsorption-active groups. Functionalized eight-shaped, daisy-like and theta-shaped macromolecules are considered as well. By using a model of an ideal chain with point-type defects in a slit-like pore we derive equations for the distribution coefficient covering all modes of chromatography of functionalized polymers of any molar mass in both narrow and wide pores. Additionally simple approximate formulae are obtained for a number of important modes of chromatography; chromatograms are simulated for model mixtures of polydisperse non-functional and functional polymers. By using the theory we analyze separation of polymers by molar mass, functionality and topology. Although there is a principal possibility to use adsorption chromatography or size-exclusion chromatography (SEC), we conclude that the liquid chromatography at the critical condition (LCCC) is especially efficient for separation of polydisperse polymers by both functionality and topology. The theory predicts that functionalized linear and cyclic polymers can be separated from each others by LCCC even better than non-functionalized ones. The LCCC behavior of some other types of polymers such as comb-like and semicyclic ones is discussed as well.     

Electroless plating of copper on polyimide films modified by surface grafting of tertiary and quaternary amines polymers

Argon plasma-pretreated polyimide (PI, Kapton^® HN) films were subjected to UV-induced surface graft copolymerization with N,N′-(dimethylamino)ethyl methacrylate (DMAEMA) and 2-(trimethylammonium)ethyl methacrylate chloride (TMMAC). The DMAEMA graft-copolymerized PI (DMAEMA-g-PI) surfaces were also quaternized and amino-functionalized with 3-bromopropylamine hydrobromide (the Q-DMAEMA-g-PI surfaces). The surface composition and the degree of quaternization of the graft-modified PI films were determined by X-ray photoelectron spectroscopy. The DMAEMA-g-PI, Q-DMAEMA-g-PI and TMMAC graft-copolymerized PI (TMMAC-g-PI) surfaces can be activated directly by PdCl₂, in the absence of prior sensitization by SnCl₂ (the ‘Sn-free’ activation process), for the subsequent electroless plating of copper. A shorter induction time for the electroless deposition of copper was found for the palladium-activated Q-DMAEMA-g-PI and TMMAC-g-PI surfaces than for the palladium-activated DMAEMA-g-PI surface. The T-peel adhesion strength of the electrolessly deposited copper with the Q-DMAEMA-g-PI surface was enhanced to above 6 N/cm, in comparison to only about 4 N/cm for the DMAEMA-g-PI surface, about 2.5 N/cm for the TMMAC-g-PI surface, or about 0.5 N/cm for the PI surface with argon plasma treatment alone.     

Synthesis and characterization of polyesteramides having short Nylon-6 segments in the main chains through polycondensation and chain extension

A Nylon-6 oligomer (PrePA) was synthesized by ring-opening polymerization from ε-caprolactam with 2-amino-ethanol under the catalysis of H₃PO₃. Polyesteramide prepolymers (PrePEAs) having amide content from 10 to 60 mol% were prepared through melt polycondensation from adipic acid, 1,4-butanediol and the PrePA. Chain extension of PrePEAs was carried out at 200 °C using 2,2′-(1,4-phenylene)-bis(2-oxazoline) and carbonylbiscaprolactamate as combined chain extenders. The chain-extended polyesteramides (ExtPEAs) with intrinsic viscosity up to 0.61 dL/g were synthesized. The ExtPEAs were characterized by FT-IR and ¹H NMR spectra, differential scanning calorimetry, wide angle X-ray scattering, thermogravimetric analysis and tensile test. The results showed that the ExtPEAs mainly crystallized in the Nylon-6 crystallites. ExtPEAs had T_g from −46.71 to 4.28 °C, T_m from 106.69 to 139.92 °C, thermal stability with initial decomposition temperature over 339 °C, tensile strength up to 30.89 MPa and stain at break higher than 797.1%. These ExtPEAs were strong, thermally stable and tough thermoplastic polymers.     

Cellular affinity of polyamides having various functional groups. I. Platelet adhesion

Various polyamides having a different density of hydrogen bonding, of hydrophilic character, and containing ionic groups have been synthesized and their blood compatibilities were evaluated in terms of the adhesion behavior of blood platelets on polyamide by the microsphere column method. Polyamides containing anionically charged groups such as carboxylate or sulfonate groups adsorbed fewer blood platelets than those with undissociated carboxylate groups. Polyamides having thioether groups adsorbed fewer platelets than those having ether groups. Introduction of a rigid piperazine unit caused an increase in platelet adhesion.