Polyamides were synthesized from diacids containing a s‐triazine ring and two aromatic diamines, namely 4,4′‐diaminodiphenyl ether (ODA) and 4,4′‐diaminodiphenylmethane (MDA), by direct polycondensation using the phosphorylation reaction. Polymers thus obtained were characterized by viscosity measurement, IR spectroscopy, thermogravimetry, X‐ray diffraction, and solubility tests. These polyamides had inherent viscosities in the range of 0.51–0.77 dL/g, and were amorphous in nature. All the polymers were readily soluble in various organic solvents and did not lose weight below 270°C in air.
SynopsisEight new diisocyanate monomers containing s-triazine ring have been prepared from the parent diacids via the Curtius rearrangement of the corresponding diacyl azides. The parent diacids were synthesised by the reaction of pand m-hydroxybenzoic acid with 6-methoxy-2,4dichloro-s-triazine, 6-phenoxy-2,4-dichloro-s-triazine, 6-phenyl-2,4-dichloro-s-triazine, and 2-diphenylamino-4,6-dichloro-s-triazine respectively. Polyurethanes have been synthesised by solution polymerization of these diisocyanates with ethylene glycol in N, N-dimethylacetamide (DMAC). The resulting polymers were characterized by IR spectroscopy, viscosity measurement, solubility tests, and softening points.
SYNOPSISAs a part of our work in the area of transesterification chemistry, we have studied the transesterification of dimethyl terephthalate/isophthalate with bisphenol-A for the synthesis of aromatic polyester. The process comprises two steps. The first step comprises preparation of aromatic polyester prepolymer by reacting the dimethyl esters of terephthalic/isophthalic acids and bisphenol-A in the melt phase via catalyzed interchange reaction. The second step involves the postpolycondensation of aromatic polyester prepolymer under reduced pressure, eliminating the by-product and driving the equilibrium of the reversible reaction to the formation of a high molecular weight aromatic polyester. In both steps, methanol is eliminated as a by-product. The method explored is the simplest one, permits the use of commercial materials as the feed stock, and leads to a low boiling by-product that can be recycled. 0 1996 John Wiley & Sons, Inc.
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