Preparation and properties of polyamides containing thianthrene units

New polyamides containing thianthrene tetraoxide were synthesized from 2,7-dichloroformylthianthrene-5,5′,10,10′-tetraoxide (A) and various diamines by the low temperature solution polycondensation technique. The resulting polyamides were characterized by i.r. and ¹H-NMR spectra and elemental analysis. The polyamides had inherent viscosities of 0.56–1.21 dl/g in DMA at 30°. All the polymers dissolved readily at room temperature in polar aprotic solvents. Density, crystallinity and thermal stability of these polyamides have been determined. In order to characterize the polymers, a model compound was also prepared from A and p-toluidine.     

Preparation of new poly(ether-amide-imide)s from 1,4-bis-[4-(trimellitimido)phenoxy]butane and aromatic diamines via direct polyamidation

Several new Poly(ether-amide-imide)s were prepared by direct polycondensation reactions of 1,4-bis-[4-(trimellitimido)phenoxy]butane with various aromatic diamine. Two direct polycondensation techniques were used: direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone/triphenyl phosphite/calcium chloride/pyridine and direct polycondensation in a tosyl chloride/pyridine/N,N-dimethylformamide system. All the monomers and polymers were fully characterized by means of FTIR, ¹H-NMR spectroscopy and elemental analyses and properties of the polymers including solution viscosity, thermal behavior and solubility were studied.     

Narrow molecular weight distribution of condensation polymers achieved by adding monomers in many batches

The Z transform method has been used to calculate the molecular weight distribution (MWD) of condensation polymers. The MWD obtained by using Z transform is explicitly discrete. The method is illustrated for two cases: (1) further polycondensation of AB prepolymers with certain initial MWD, and (2) polycondensation of AB and Ar (r is the number of A type functional groups) monomers where AB monomers are added in several batches. In the latter case, it is found that the resulting MWD is much narrower than that of one-batch polycondensation. The trick of producing narrow MWDs of condensation polymers is merely a consequence of keeping AB monomer concentration as low as possible during the reaction in order to suppress the condensation reaction between monomeric AB molecules. The theoretical prediction has been confirmed by Monte Carlo simulation. Therefore, it provides a new possible technique for obtaining narrow MWD polymers through polycondensation reactions.     

A convenient room temperature polycondensation toward hyperbranched AB2‐type all‐aromatic polyesters with phenol terminal groups

As a convenient alternative to the classical melt polycondensation the one‐pot solution polycondensation of suitable AB₂ monomers under mild conditions has been successfully adapted to hyperbranched all‐aromatic polyester with phenol terminal groups. The polymerization was performed in solution at room temperature directly using commercially available 3,5‐dihydroxybenzoic acid as monomer and 4‐(dimethylamino) pyridinium 4‐tosylate as catalyst to suppress the formation of N‐acylurea. Different carbodiimides as coupling agents were investigated to find the optimal esterification conditions. The polymers have been characterized extensively and were compared with their well‐known analogs synthesized in melt. The characterization was carried out by NMR spectroscopy, size exclusion chromatography, and asymmetric flow‐field flow fractionation as an alternative separation technique for multifunctional polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5158–5168, 2009     

Palladium‐Catalyzed Chain‐Growth Polycondensation of AB‐type Monomers: High Catalyst Turnover and Polymerization Rates

Chain‐growth catalyst‐transfer polycondensations of AB‐type monomers is a new and rapidly developing tool for the preparation of well‐defined π‐conjugated (semiconducting) polymers for various optoelectronic applications. Herein, we report the Pd/PtBu₃‐catalyzed Negishi chain‐growth polycondensation of AB‐type monomers, which proceeds with unprecedented TONs of above 100 000 and TOFs of up to 280 s^?1. In contrast, related AA/BB‐type step‐growth polycondensation proceeds with two orders of magnitude lower TONs and TOFs. A similar trend was observed in Suzuki‐type polycondensation. The key impact of the intramolecular (vs. intermolecular) catalyst‐transfer process on both polymerization kinetics and catalyst lifetime has been revealed.     

Synthesis and Characterization of Photosensitive Phosphorus Based Polymers Containing α,β‐Unsaturated Ketones in the Main Chain

1,3‐Bis(4‐hydroxyphenyl)propenone (BHPP) and 3‐(4‐hydroxy‐3‐methoxy phenyl)‐1‐(4‐hydroxyphenyl)propenone (HMPHPP) were used as monomers for preparing photosensitive phosphorus containing polyesters. The photosensitive monomers BHPP and HMPHPP were prepared respectively by refluxing 4‐hydroxybenzaldehyde and 3‐methoxy‐4‐hydroxybenzaldehyde with 4‐hydroxy acetophenone. The polyesters were synthesized by interfacial polycondensation of photosensitive diols with N‐phenylphosphoramidic dichloride using hexadecyltrimethyl ammonium bromide (HDTMAB) as phase‐transfer catalyst. Copolymers were also prepared by incorporating terephthaloyl chloride in the polymer backbone. The synthesized monomers and polymers were characterized by UV, FT‐IR and ¹H, ¹³C and ³¹P‐NMR spectroscopic techniques. The resulting polymers had inherent viscosities in the range of 0.15–0.51 dL/g and showed good solubility in polar organic solvents. The thermal properties of the polymers were studied by thermogravimetric analysis and differential scanning calorimetry under nitrogen atmosphere. The TGA data revealed that the 10% weight loss occurs at 275–320°C and all the synthesized polymers showed high char residues. DSC studies indicate that these polymers possess T_g in the range of 48 to 64°C. The photosensitive property of the polymers in film and solution state was investigated by ultraviolet spectroscopy. The effect of incorporation of terephthaloyl unit on photocrosslinking and thermal properties of the polymers was also studied.     

New thermally stable condensation polymers containing central ketal moieties derived from malonaldehydetetramethyl acetal and dihydroxyaromatic compounds

Abstract

A number of new condensation polymers with acetal units in the main chain and having linear and ladder-form structure and high thermal stability were synthesized by solution polycondensation of dihydroxyaromatic compounds with malonaldehydetetramethyl acetal as a reactive protected 1,3-dicarbonyl compound. Optimal conditions for polycondensation were obtained via study of the model compounds. In order to obtain high molecular weight polymers, general investigations on the influence of reaction conditions, such as monomer concentration and reaction temperature were carried out. All polymers were obtained in high yields and moderate inherent viscosity ranging from 0.25 to 0.41?dL/g. The proposed chemical structures of condensation polymers were confirmed by ¹H-NMR, ¹³C-NMR, FTIR spectroscopies, TGA, and DSC. Thermal analysis indicated that these polymers are stable up to 360?°C, and a 10% weight loss (T₁₀) were recorded on the TG curves in the temperature range of 381–411?°C in nitrogen atmosphere, indicating their good thermal stability.     

Synthesis and characterization of new unsaturated polyesters and copolyesters containing azo groups in the main chain

A new interesting class of linear unsaturated polyesters based on dibenzylidenecycloalkanones have been synthesized by interfacial polycondensation of 4,4^′-azodibenzoyl chloride or 3,3^′-azodibenzoyl chloride with: 2,5-bis(p-hydroxybenzylidene)cyclopentanone I, 2,6-bis(p-hydroxybenzylidene)cyclohexanone II, 2,6-divanillylidenecyclohexanone III, or 2,7-bis(p-hydroxybenzylidene)cycloheptanone IV at ambient temperature. The copolyesters are also synthesized from the monomers I, II, III or IV with the diacid chlorides. The resulting polyesters and their copolyesters were characterized by elemental analyses, IR spectroscopy and solubility. Additionally, inherent viscosity of the polyesters in the range 0.32-0.86 dL g⁻¹ and the inherent viscosity of the copolyesters in the range 0.28-0.65 dL g⁻¹ were determined. The UV-visible spectra of certain polymers were measured in m-cresol solution and showed a characteristic absorption band at 435-473 nm due to n-π^* transition. The thermal properties of the polymers were evaluated by thermo gravimetric analysis and differential scanning calorimetry measurements and correlated with their structural units. The crystallinity of some polyesters and copolyesters were tested. In addition, the electrical properties of all polyesters and copolyesters were measured.     

Studies on heat resistant poly(aryl pyromellitimide-ether)s

A new series of aromatic heterocyclic poly(aryl pyromellitimide-ether)s have been synthesized from various disodium metal bisphenolate salts with an N,N′-bis(p-nitrophenyl)pyromellitimide via aromatic nitro displacement solution polycondensation in dipolar aprotic solvent at elevated temperature. The reaction was rapid and free of side reactions, with good yield. The resultant polymers were characterized by intrinsic viscosity, infrared and ¹H-, ¹³C-NMR spectroscopy. Thermal behavior of the synthesized polymers was evaluated by thermogravimetric analysis and correlated with their structures. The poly(tetraphenyl methane pyromellitimide-ether) showed better thermal stability than the other polymers. © 1996 John Wiley & Sons, Inc.     

Thermal and optical properties of some phosphorus‐containing poly(1,3,4‐oxadiazole‐ester‐imide)s

A series of phosphorus‐containing poly(1,3,4‐oxadiazole‐ester‐imide)s was prepared by polycondensation reaction of an aromatic dianhydride, namely 1,4‐[2‐(6‐oxido‐6H‐dibenz<c,e><1,2>oxaphosphorin‐6‐yl)]‐naphthalene‐bis(trimellitate)dianhydride, with different aromatic diamines containing 1,3,4‐oxadiazole ring. A solution imidization procedure was used to convert quantitatively the poly(amic acid) intermediates to the corresponding polyimides. The chemical structures of the monomers and polymers were confirmed by Fourier transform infrared, ¹H NMR and ³¹P NMR spectroscopy. The polymers were easily soluble in polar solvents such as N‐methyl‐2‐pyrrolidone (NMP), N,N‐dimethylformamide and tetrahydrofuran. They exhibited good thermal properties having the decomposition temperature above 380°C and the glass transition temperature in the range of 201–232°C. Due to the presence of phosphorus the polymers gave high char yield in termogravimetric analysis, hence good flame retardant properties. Optical properties were analyzed in solution by using UV–vis and photoluminescence spectroscopy. Solutions of the polymers in NMP exhibited photoluminescence in the blue region. Copyright © 2010 John Wiley & Sons, Ltd.     

Phosphorus containing polymers. III. Polyimidophosphonates

Synthesis of dihydroxybisimide monomers and their subsequent polycondensation with dichlorophenylphosphine oxide by use of a phase-transfer catalyst are reported. The monomers were characterized by melting point, elemental analysis, and IR spectroscopy. The polyimidophosphonates were characterized by viscosity measurement, molecular weight determination, elemental analysis, IR, ESCA, ¹H-NMR, ³¹P-NMR, and X-ray diffraction. Thermal stability and glass transition temperature (T_g) of the polymers were evaluated by TGA, DTA, and TMA. These polymers are self-extinguishing and readily soluble in highly polar solvents like DMF, DMSO, DMAC, NMP, HMPA, etc. © 1994 John Wiley & Sons, Inc.     

Carbazole main-chain polymers for multifunctional materials: Synthesis and characterization

A series of α,ω-bis(3-formylcarbazolyl)alkane monomers have been prepared starting from carbazole and α,ω-dibromoalkane in two steps. Main-chain polymers with carbazole substituted with one acceptor group as the nonlinear optical (NLO) chromophores and photoconductive moieties were synthesized by the Knoevenagel polycondensation of α,ω-bis(3-formylcarbazolyl)alkane and 1,6-bis(cyanoacetoxy)hexane using 4-(N,N-dimethyl)pyridine (DMAP) as a base. This Knoevenagel polycondensation involved two stages: polycondensation was first carried out in tetrahydrofuran solution, and then polycondensation was allowed to continue in the solid-state after removal of solvent. All of these main-chain polymers characterized by spectroscopic methods and elemental analyses are soluble in common low boiling organic solvents, such as chloroform. These polymers were found to be amorphous with glass transition temperatures in the range of 94–117°C by differential scanning calorimetry. This two-stage polycondensation gave polymers with weight-average molecular weight in the range of 25,000–72,000 g/mol by gel permeation chromatography. The study of the nonlinear optical and photorefractive properties of these polymers is in progress. © 1996 John Wiley & Sons, Inc.     

s‐Triazine‐based hyperbranched polyethers: Synthesis,characterization, and properties

A series of s‐triazine‐based hyperbranched polyethers (HBPE) have been synthesized to obtain thermostability but flexible polymers by an interfacial polycondensation of different diols as A₂ and cyanuric chloride as B₃ monomers using A₂ + B₃ approach in the presence of a phase transfer catalyst. The polymerization reaction parameters are optimized, and the results indicate that the optimum conditions for the interfacial polycondensation are a 2:3 mole ratio of cyanuric chloride to diol using butanediol, benzyldimethylhexadecyl ammonium chloride as the catalyst, dichloromethane as the organic solvent, and a three‐step procedure with keeping the reaction mixture at different low temperatures for 2h/2h/5h. Other techniques such as high‐temperature solution, one‐step polycondensation, and transesterification were also carried out to synthesize the HBPE but proved to be not suitable due to large number of side reactions. The synthesized polymers were characterized by FTIR, ¹H NMR, and ¹³C NMR spectroscopy, hydroxyl number determination, solution viscosity measurements, and GPC analysis. The thermal behavior of the hyperbranched polymer was investigated by thermogravimetric analysis and differential scanning calorimetry. All the results were compared with those from an analogous linear polyether, obtained from 2‐methoxy‐4,6‐dichloro‐s‐triazine and butanediol by using the same polymerization technique. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3994–4004, 2010     

New poly(amide-imide) siloxane copolymers by polycondensation

Some new poly(amide-imide) siloxane copolymers have been synthesized by solution polycondensation of some aromatic diamines with siloxanic diacids having preformed imide rings. Two polycondensation techniques were used: polycondensation of aromatic diamines with diacid chlorides and direct polycondensation of aromatic diamines with diacids in the presence of organic phosphites, following the Yamazaki-Higashi phosphorylation technique. In all cases the reactions were carried out using equimolecular amounts of the two monomers, in polar aprotic solvents and inert atmosphere.The obtained compounds were characterized by elemental C, H and Si analysis, solubility tests, IR and ¹H-NMR spectrometry. Thermogravimetric curves were also recorded. All data agree with the proposed structures.     

Ferrocene‐based organophosphorus liquid–crystalline polymers: Synthesis and characterization

Ferrocene‐containing polyphosphate and phosphonate esters were synthesized by the solution polycondensation method. The structure of the polymers was confirmed using various spectroscopic techniques. The formation of two types of chain blocks was confirmed by ³¹P NMR spectroscopy. Hot stage optical polarized microscope (HOPM) analysis revealed that all the polymers have a liquid–crystalline property. The char yields of the synthesized similar polymers were much higher than those of nonphosphorus polymers already reported in the literature. DSC analysis confirmed our predictions over the liquid–crystalline property, glass‐transition temperature, isotropization temperature, and thermal stability of the polymers. The effects of substitution on the side chain, structure of the liquid‐–crystalline phase, and thermal stability of the polymers have also been discussed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2396–2403, 2001     

Synthesis and properties of polycondensation polymers from compounds with asymmetric functional groups

The effect of conditions of polycondensation on the structure of polymers formed from monomers with symmetric and asymmetric functional groups by nonequilibrium polycondensation has been studied for the system with acceptor-catalytic polyesterification of β-hydroxyethyl ethers of bisphenols and terephthalic acid chloride in the presence of triethylamine. Polymers with statistical or regular arrangement of diol residues in the chain can be produced in such systems, depending on the way in which starting compounds are introduced in the reactor. A difference in the reactivity of functional groups in an asymmetric monomer is not sufficient to produce polycondensation polymers with a regular structure. Gradual introduction of the symmetric monomer is essential to yield polymers with predominant “head-to-head” (“tail-to-tail”) configurations. Some properties of the resulting polymers have been studied. Polymers with ordered residues of the asymmetric monomers in the macromolecules have higher softening temperatures and an increased tendency for crystallization than the statistic polymers.     

Significant Difference in Semiconducting Properties of Isomeric All‐Acceptor Polymers Synthesized via Direct Arylation Polycondensation

The direct arylation polycondensation (DArP) appeared as an efficient method for producing semiconducting polymers but often requires acceptor monomers with orienting or activating groups for the reactive carbon‐hydrogen (C‐H) bonds, which limits the choice of acceptor units. In this study, we describe a DArP for producing high‐molecular‐weight all‐acceptor polymers composed of the acceptor monomers without any orienting or activating groups via a modified method using Pd/Cu co‐catalysts. We thus obtained two isomeric all‐acceptor polymers, P1 and P2, which have the same backbone and side‐chains but different positions of the nitrogen atoms in the thiazole units. This subtle change significantly influences their optoelectronic, molecular packing, and charge‐transport properties. P2 with a greater backbone torsion has favorable edge‐on orientations and a high electron mobility μ_e of 2.55 cm² V^?1 s^?1. Moreover, P2‐based transistors show an excellent shelf‐storage stability in air even after the storage for 1 month.     

Grafting on crosslinked polymer beads by ATRP from polymer supported N-chlorosulfonamides

Grafting of methyl methacrylate (MMA) and ethyl acrylate (EA) monomers from immobilized N-chlorosulfonamide (NCSA) groups on crosslinked polystyrene-based beads have been achieved by copper mediated atom transfer radical polymerisation (ATRP) methodology. The initiation takes place via NCSA groups on the polymer, created by chlorination of crosslinked polystyrene sulfonamides. Using CuBr and hexacishexyl triethylenetetramine ligand for MMA and EA grafting showed a first order kinetics for each monomers.Polymers with 3.18 mmol g⁻¹ of NCSA groups have a progressive mass increase in accordance with increasing MMA graft polymerisation up to 380.0% grafting obtained after 6 h.By the method presented, grafting of MMA and EA have been successfully achieved with negligible amounts of free polymer formation (6.2%) in the solution. Hence grafting by ATRP through polymer supported NCSA is superior to the common radical grafting methods which are yielding free polymers simultaneously.The method provides an efficient procedure in preparing core-shell type of polymers, with retention of the bead shapes.     

氟取代聚芳醚酮低温合成及其结构研究

通过傅克酰基化反应合成4,4'-二(4-氟苯甲酰基)二苯醚、4,4'-二(五氟苯甲酰基)二苯醚、4,4'-二(4-氟苯甲酰基)二苯硫醚以及4,4'-二(五氟苯甲酰基)二苯醚4种长链双卤单体,并进一步制备了含二氮杂萘酮聚芳醚酮聚合物.通过多氟取代双卤单体在含二氮杂萘酮聚芳醚酮聚合物主链中引入氟原子.多氟取代双卤单体具有多...     

Synthesis and characteristics of the poly(carboxybetaine)s and the corresponding cationic polymers

Two types of carboxybetaines and their corresponding cationic monomers and polymers are synthesized in this study. Comparing the chemical shifts of the methylene groups in the cationic monomers and carboxybetaines in both ¹H- and ¹³C-NMR spectra reveal that the respective methylene groups are clearly distinguished from their chemical shifts in ¹H- and ¹³C-NMR spectra. The solubilities, moisture regain properties, and solution properties of the poly(carboxybetaine)s and cationic polymers are investigated in relation to their molecular structures. Because the cationic polymers were ionized in an aqueous solution, the cationic polymers were more soluble than the poly(carboxybetaine). For the various functional groups of poly(carboxybetaine)s and cationic polymers, the order of tendency for moisture regain is  COO >  CONH . Results obtained from the reduced viscosity for cationic poly(TMMPAMS) are reversed from that for zwitterionic poly(DMAEAPL). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3527–3536, 1997