Production of 5-(chloromethyl)furan-2-carbonyl chloride and furan-2,5-dicarbonyl chloride from biomass-derived 5-(chloromethyl)furfural (CMF)

Biomass-derived CMF is oxidized to the acid chloride CMFCC in a single step using inexpensive t-butyl hypochlorite. Likewise, DFF, also a CMF derivative, is oxidized directly to the diacid chloride FDCC. The products are platforms for a variety of chemical derivatives of carbohydrates.

Microwave-assisted synthesis and characterization of some optically active poly(ester-imide) thermoplastic elastomers

Pyromellitic dianhydride (1) was reacted with L-leucine (2) to result in [N,N'-(pyromellitoyl)-bis-L-leucine diacid] (3). This compound (3) was converted to N,N'-(pyromellitoyl)-bis-L-leucine diacid chloride (4) by reaction with thionyl chloride. The microwave-assisted polycondensation of this diacid chloride (4) with polyethyleneglycol-diol (PEG-200) and/or three synthetic bisphenols furnish a series of new PEIs and Co-PEIs in a laboratory microwave oven (Milestone). The resulting polymers and copolymers have inherent viscosities in the range of 0.31- 0.53 dl g-1. These polymers are optically active, thermally stable and soluble in polar aprotic solvents such as DMF, DMSO, NMP, DMAc and sulfuric acid. All of the above polymers were fully characterized by IR spectroscopy, 1H NMR spectroscopy, elemental analyses, specific rotation and thermal analyses. Some structural characterizations and physical properties of these optically active PEIs and Co-PEIs are reported.

Probing the Properties of Nanocomposites Synthesized from Aramid and Surface-Modified Clay

Nanocomposites were prepared by the inclusion of layered silicates into the aramid matrix via a solution intercalation technique. Polyamide was synthesized by reacting 4,4′-oxydianiline with isophthaloyl chloride and then end-capping with carbonyl chloride end groups using excess diacid chloride. The compatibility between the two phases was obtained through surface modification of montmorillonite with long-chain alkyl diamine. The nanocomposites were characterized with regard to structural, morphological, mechanical, thermal, and water absorption measurements. These investigations confirmed the formation of delaminated and disordered intercalated nanostructures at different clay loadings. Mechanical properties were significantly enhanced relative to pristine polyamide, even with the addition of only 2 wt-% of nanoclay. Thermal decomposition temperatures of the nanocomposites were in the range 300–450°C. Glass transition temperature data exhibited improvement (123°C) up to 16 wt-% addition of organoclay. Water absorption of the neat aramid was rather high (5.7%), but decreased with augmenting clay content.

Synthesis and Characterization of Highly Soluble and Heat Stable New Poly(amide-ether)s Containing Pyridine Rings in the Main Chain

A pyridine-based diacid containing ether linkage was synthesized via reaction of 2,6-dichloropyridine with 3-hydroxybenzoic acid in presence of potassium hydroxide in dimethyl sulfoxide (DMSO). The corresponding diacid chloride was synthesized by reaction of the diacid with oxalyl chloride. New poly (amide-ether)s were prepared by solution polycondensation reaction of the prepared diacid chloride with different commercial aromatic diamines. The synthesized polymers were characterized by elemental analysis, IR, and 1H NMR spectra, wide-angle X-ray diffraction, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC); inherent viscosity and solubility were studied. These polymers showed high thermal stability and good solubility.

Study on synthesis and characterization of novel optically active poly(amide-imide)s based on bis(p-aminobezoic acid)-N-trimellitylimido-S-valine via direct polycondensation

N-Trimellitylimido-S-valine (3) was prepared by reaction of trimellitic anhydride (1) with S-valine (2) in acetic acid solution at refluxing temperature. This diacid was reacted with thionyl chloride and N-trimellitylimido-S-valine diacid chloride (4) was obtained in quantitative yield. The reaction of this diacid chloride with p-aminobenzoic acid was carried out in dry tetrahydrofurane and bis(paminobenzoic acid)-N-trimellitylimido-S-valine (5) was obtained as a novel optically active amide-imide diacid monomer in high yield. The direct poly condensation of amide-imide diacid monomer with aromatic diamins such as 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, benzidine, 4,4'-diaminodiphenyl methane, 1,4- phenylene diamine and 2,5-diamino toluene was carried out in tosyl chloride/ pyridine/dimethylformamide system. The resulting novel optically active poly(amide-imide)s (PAIs) with inherent viscosities ranging from 0.24-0.76 dLg-1, were obtained in good yield. All of these polymers were fully characterized with FTIR spectroscopy and specific rotation. Some elemental analysis, thermal properties and 1H-NMR of these new optically active PAIs are also reported.