β Scribed by S. R. Shukla; K. S. Kulkarni
No coin nor oath required. For personal study only.
Oligomers were obtained from polyester samples by solvent extraction and dissolution methods. Dioxane, chloroform, and chlorobenzene were used for the extraction method, whereas dimethyl formamide and phenol : tetrachloroethane (1 : 1 mixture) were used for the dissolution method. The oligomers were separated and analyzed by a thin-layer chromatographic technique. It was observed that extraction with chloroform and dissolution with phenol : tetrachloroethane gave higher oligomer contents. Also, the values were higher for as-spun fibers. Thin-layer chromatographic analysis showed that in all the cases lower oligomers were obtained with a maximum of the cyclic trimer, whereas the efficiencies of solvents varied for removal of higher oligomers.
π SIMILAR VOLUMES
New phthalide-containing bisphenols, phenolphthalein-N-(3-methylanilide) (3-PMA), and phenolphthalein-N-(4-methylanilide) (4-PMA), were synthesized from phenolphthalein and m-and p-toluidines. These bisphenols were polycondensed with terephthaloyl chloride (TPC) using an interfacial or solution poly
New polyester-sulfur compositions with increased tensile strength were obtained by using new thiopolyesters crosslinkable with sulfur, derived from diphenylmethane-4,4-di(methylthiopropionic acid) and ethanediol (E-P) or 2,2-oxydiethanol (ODE-P). Such characteristics as hardness, tensile, thermomech