Segmented-Block Poly(ether amide)s Containing Flexible Polydisperse Polyethyleneoxide Sequences and Rigid Aromatic Amide Moieties

We describe the synthesis and characterization of three novel aromatic diamines containing oxyethylene sequences of different lengths. These diamines were polymerized using the low-temperature solution polycondensation method with isophthaloyl chloride (IPC), terepthaloyl chloride (TPC), [1,1’-biphenyl]-4,4’-dicarbonyl dichloride (BDC), and 4,4′-oxybis(benzoyl chloride) (OBE), obtaining twelve poly(ether amide)s with short segments of polydisperse polyethyleneoxide (PEO) sequences in the polymer backbone. These polymers show reasonably high molecular mass materials (Mw > 12,000), and the relationship between their structure and properties has been carefully studied. Compared with conventional polyamides containing monodisperse PEO sequences, the polydispersity of the PEO segments within the structural units exerts a significant influence on the crystallinity, flexibility, solubility, and the thermal properties of the polymers. For instance, the all-para oriented polyamides (TPCP-A), with an average number of 8.2 ethylenoxide units per structural unit can be transformed conventionally (Tm = 259 °C) in comparison with thermally untransformable polymer with 2 ethylenoxide units (Tm = 425 °C).

Heteroaromatic Polyamides with Improved Thermal and Mechanical Properties

We prepared high-performance aromatic copolyamides, containing bithiazole and thiazolo-thiazole groups in their main chain, from aromatic diamines and isophthaloyl chloride, to further improve the prominent thermal behavior and exceptional mechanical properties of commercial aramid fibers. The introduction of these groups leads to aramids with improved strength and moduli compared to commercial meta-oriented aromatic polyamides, together with an increase of their thermal performance. Moreover, their solubility, water uptake, and optical properties were evaluated in this work.

Methods for the synthesis of dichloroanhydrides of phthalic acids

Dichloroanhydrides of isophthalic (isophthaloyl chloride) and terephthalic (terephthaloyl chloride) acids are, undoubtedly, strategically important compounds. Among their main application areas is synthesis of Aramid fibers to be used for manufacturing dual use materials including synthesis of Terlon®, Phenylon®, Armos®, Tegelen®, SVM®, and Rusar® fibers. Specific requirements for quality of the target anhydrides and feedstock determine the choice of the synthetic methods. In the review paper, various methods, including catalytic methods, for the synthesis of iso- and terephthaloyl chlorides based on the use of different types of feedstock are discussed. Main methods for analysis of these compounds are described in detail.

Synthesis of a tethered dibenzotetramethyltetraaza[14]annulene macrocycle and the di-nickel(ii) derivative

Selective reaction of 2,6-isophthaloyl chloride at the methine positions of two dibenzotetramethyltetraaza[14]annulene (tmtaa) units results in tethering of the macrocycles by either one or two 2,6-isophthaloyl bridging groups.

Novel organosoluble polyarylates based on diphenylamine-fluorene units

Two kinds of polyarylates with diphenylamine-fluorene units were synthesized from the bisphenol monomer “ N, N-di(4-hydroxyphenyl)-2-amino-9,9-dimethylfluorene” with two different benzenedicarbonyl chlorides. These polyarylates were highly soluble in N, N-dimethylacetamide, tetrahydrofuran, and chloroform and could be easily solution-cast into transparent films. Both of the polyarylates exhibited a couple of reversible redox with half-wave potentials in the range of 0.87–0.90 V. During the electrochromic process, the color of the film changed from colorless (neutral state) to grey green (oxidation state) with a high coloration efficiency of 242 cm2 C−1. Compared with the polyarylates prepared from terephthaloyl chloride, the polyarylates prepared from isophthaloyl chloride exhibited enhanced fluorescence because of the reduced charge-transfer effect. Furthermore, its fluorescence could be reversibly switched under the applied potentials.

An alternative synthesis of benziporphyrins starting from isophthaloyl chloride

An alternative route to benziporphyrins has been developed. Reaction of an [Formula: see text]-unsubstituted pyrrole ethyl ester with isophthaloyl chloride in the presence of aluminum chloride afforded a diketone that underwent selective reduction with diborane to give a benzitripyrrane. Cleavage of the ethyl esters with sodium hydroxide in refluxing ethylene glycol, followed by acid catalyzed condensation with a pyrrole dialdehyde and oxidation with DDQ, generated the targeted benziporphyrin product. Spectrophotometric titration of the benziporphyrin with trifluoroacetic acid (TFA) demonstrated the sequential formation of mono- and dicationic species. At lower dilutions, the free base benziporphyrin showed unusually strong [Formula: see text] coupling between two adjacent methyl substituents, indicating that the connecting unit has substantial olefinic characteristics.

Preparation and characterization of new aromatic poly(ether ester)s bearing cardo xanthene groups

A series of new aromatic poly(ether ester)s containing cardo xanthene groups were synthesized by phase transfer–catalyzed interfacial polycondensation of three cardo bisphenols such as 9,9-bis(4-hydroxyphenyl)xanthene, 9,9-bis (4-hydroxy-3-methylphenyl)xanthene, and 9,9-bis(4-hydroxy-3,5-dimethylphenyl)xanthene with terephthaloyl chloride and isophthaloyl chloride. Inherent viscosities and number average molecular weights of the polymers were in the range 0.56–0.80 dL g−1 and 30,300–36,200, respectively. The resulting poly(ether ester)s exhibited high glass transition temperatures ranged from 208°C to 274°C, and their 10% weight loss temperatures were in the range of 440–458°C with char yields above 45% at 600°C under a nitrogen atmosphere. All the poly(ether ester)s were amorphous and readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, meta-cresol, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidinone at room temperature and could be cast into tough, transparent, and flexible films with tensile strengths of 68.2–86.8 MPa, elongations at break of 2–3%, and tensile moduli of 5.7–7.8 GPa.

Synthesis and Characterization of the Hyperbranched Polyamide with Triphenyl Phosphorus Structure and the Influence on Mechanical Property of Nylon-6

Due to the unique molecular structure, hyperbranched polymers showed many characteristics,such as high solubility, low viscosity and high-activity. Therefore, it had been widely applied in different areas. In this paper, isophthaloyl chloride (IPC) was used as A2monomer and tri (3-aminophenyl) phosphine oxide (TAPPO) was used as B3monomer, compounding hyperbranched polyamide with triphenyl phosphorus structure . The best reaction conditions were obtained that the molar ratio of TAPPO and IPC was 1.5:1, the reaction temperture was 50°C, the reaction concentration was 0.1 mol/L and the reaction time was 2h.Besides, the structure of the polymer was characterized by FT-IR and H1-NMR analysis.The1H-NMR result showed that the branched degree of hyperbranched polyamide was 0.36.The DSC result showed that the glass transition temperature (Tg) was 130.7 °C. When the addition of P-HBPA content was 0.5% in PA6/P-HBPA blends, the properties of tensile strength, elongation at break and impact strength reached the maximum.