In this paper, we report on the synthesis of five high molecular weight random copolyesters containing chalcone moieties in their main chain by the polycondensation of a chalcone diol with an aromatic diacid chloride (terephthalic acid) and four varying aliphatic diacid chlorides malonyl chloride, pimeloyl chloride, suberoyl chloride, azelaoyl chloride and sebacoyl chloride in a DMF/triethylamine medium. The chalcone used in the copolymerization process was prepared by an acid-catalyzed Claisen-Schmidt reaction. The synthesized aliphatic-aromatic random chalcone copolyesters were characterized by quantitative solubility and viscosity measurements which proved the copolyesters to have invariably high molecular weights. The microstructure of repeat units in the copolymer chain was established with the aid of FT-IR, 1H-NMR and 13C-NMR spectroscopic techniques. The thermal analysis by the differential scanning calorimetry (DSC) gave the glass transition temperature (Tg), the melting temperature (Tm), and the isotropization temperature (Ti) indicating a semicrystalline nature of copolyesters while the values of Tg (21.4C) and Tm (108.8C) concluded the copolyesters well suited for drug delivery applications. The inhibitory efficacy of the all five synthesized random copolyesters against the pathogenic bacteria (B. subtilis & E. coli) and the fungi (A. niger & C. albicans) was tested with the well diffusion method which demonstrated the copolyesters as good bactericidal and fungicidal agents but not as strong as the standard antibiotic, the streptomycin and the standard antifungals viz. the clotrimazole and the fluconazole.

Keywords : Random Aliphatic-Aromatic Copolyesters; Polycondensation; Chalcones; Copolymerization; GlassTransition; Melting; Isotropization; Drug-Delivery; Bactericidal; Fungicidal