Novel regular network polyester films from benezenetricarboxylic acids and glycols

Abstract

SynopsisNovel regular network polyester films were prepared from benzenetricarboxylic acids of trimesic (Y) and trimellitic (Z) acids, and glycols of ethylene (2G), tetramethylene (4G), and hexamethylene (6G) glycols. Prepolymers prepared by melt polycondensation for a short period within 1 h were cast from a DMF solution and successively post-polymerized a t various temperatures and times t o form a network. The resultant films were transparent, flexible, and insoluble in any solvents. Distortion temperature measured by a penetration mode of thermomechanical analysis (TMA) increased with increasing post-polymerization time and temperature, and leveled out at 222, 168, 125 and 75"C, for the 2GY, 2GZ, 4GY, and 6GY films, respectively. Temperatures close to 400°C a t which the probe had completely penetrated corresponded t o the thermal decomposition temperature of these films. Two broad but strong peaks in the x-ray diffraction curves appears for the 2GY, 4GY, and 6GY, suggesting the formation of some ordered supramolecular structure owing t o the regular network formed by symmetrical trimesic acid moiety, and the intensity of diffraction peaks became higher with increasing length of the methylene chain of the glycol monomer. Densities of the 2GY and 2GZ films decreased with increasing post-polymerization time and temperature. Tensile strength and Young's modulus increased and elongation decreased with increasing network formation. These tensile properties was affected by the chemical structure of the network films.

Synthesis, characterization, and enzymatic degradation of network aliphatic copolyesters

“…Biodegradable network copolyesters were prepared from glycerol (Yg) and sebacic acid (10) with succinic acid (4), 1,12-dodecanedicarboxylic acid (14), 1,18-octadecanedicarboxylic acid (20), or terephthalic acid (T). The enzymatic degradation rate of Yg10 was rapidly reduced with increasing 4, 20, and T comonomer contents and the weight loss was hardly observed for the Yg-10/4, Yg-10/20, and Yg-10/T films at the composition of more than 50 mol % comonomers.…”

“…20°for the Yg10 and copolymer films, which implies the formation of some ordered structure for these network aliphatic polyester films. [13][14][15][16][17] In addition, the diffraction peak angle is hardly affected by the copolymerization. Similar behavior was observed for Yg-10/4, Yg-10/20, and Yg-10/T films.…”

“…Succinic acid (4), sebacic acid (10), 1,12-dodecanedicarboxylic acid (14), 1,18-octadecanedicarboxylic acid (20), and dimethyl terephthalate (T) were used as received. Glycerol (Yg) was distilled under reduced pressure.…”

“…The incorporation of network structure into the polymer backbone is also expected to give better physical and chemical properties such as resistance to heat distortion and resistance to chemicals. [13][14][15][16][17][18][19] In previous papers, 20,21 we reported that network polyester films prepared from aliphatic dicarboxylic acids with medium methylene chain length (C 8 -C 12 ) and glycerol (Yg) were degraded markedly by lipase enzymes. Above all, a Yg10 film from sebacic acid and Yg lost about 60% of its original weight after incubation in a Rhizopus delemar lipase buffer solution for 2 h at 37°C.…”

Synthesis and Enzymatic Degradation of Aliphatic Polyesters Copolymerized with Trimesic Acid

“…shows wide-angle x-ray scattering (WAXS) intensity curves of 2G6A homopolymer, copolymers, and 2GY (Y-100) prepared from Y and 2G[5]. 2G6A homopolymer film exhibits a distinct crystalline pattern, whereas copolymer films show only amorphous peaks, demonstrating crystallinity of the polymer, are largely destructed by incorporation of the Y component.…”