Shanti R. Patel

Synthesis and characterization of furfural-acetone polymers

Abstract The polymeric products obtained from 2-furfurylidene methyl ketone and from furfural and acetone in the presence of base have been characterized by u.v. and i.r. spectral study, molecular weight estimation by vapour pressure osmometry and viscometric study of solutions in dioxane. Gel Permeation Chromatography of selected polymer samples was carried out to estimate polydispersity index; thermal behaviour was studied by thermogravimetric analysis. A likely course of the polymerization and the structure of polymers prepared from 2-furfurylidene methyl ketone (PFMK) are proposed.

Synthesis, characterization of m-aminophenol-furfural and m-diethylaminophenol-furfural resins

Abstract The polycondensations of m-aminophenol and m-diethyl-aminophenol with furfural has been studied under various reaction conditions. The resin samples have been characterized by i.r. spectral studies, measurement of solution viscosity, estimation of M n and by thermogravimetric analysis. The curing of selected samples by hexamine has been studied by measuring the proportion of cured material as a function of time at various temperatures.

Synthesis and characterization of keto-sulphide resins

Abstract Polycondensations of acetophenone and its 4-chloro-, bromo-, and methyl- and 3-nitro derivatives with formaldehyde in the presence of sodium hydrosulphide afford the corresponding keto-sulphide resins. These resins have been characterized by elemental analyses, estimation of M n by vapour pressure osmometry, measurement of solution viscosity in DMF, i.r. spectra and thermal gravimetric analysis. The formation of the resins is explained.

Friedel-Crafts Polymers. 8. Friedel-Crafts Polycondensation of β-Resorcylic Acid or Resorcinol with p-Xylylene Dichloride, p,p′-Dichloromethyldiphenyl Ether, and p,p′-Dichloroacetyldiphenyl Ether

Abstract Friedel-Crafts polycondensation of β-resorcylic acid (BRA) with p-xylylene dichloride (PXDC) or 4,4′-dichloromethyldiphenyl ether (DDE) in dioxane could be effected without simultaneous decarboxylation of BRA. The similar polycondensation of BRA with PXDC, DDE, or 4,4′-dichloroacetyldiphenyl ether (DADE) in nitrobenzene or in the absence of solvent at 150°C was associated with decarboxylation of BRA. Polymers having structures isomeric with those of the polycondensation product of BRA formed with subsequent in situ decarboxylation were prepared by Friedel-Crafts polycondensation of resorcinol with the above dichlorides. All the polymer samples were characterized, and those with related structures were compared. The ion-exchange properties of the polymer sample prepared from BRA and DDE in dioxane were studied.

Preparation and Study of Polymeric Metal Chelates of Poly(8-hydroxyquinoline-7,5-diylethylene)

Abstract Polymeric chelates prepared by reacting a solution of poly(8-hydroxyquinoline-7,5-diylethylene) with various metal ions in acetic acid are characterized by elemental analysis, IR and UV reflectance spectral studies, and magnetic susceptibility measurements. These properties are explicable in terms of their expected structures. TGA and electrical conductivity of these polychelates are compared mutually and also with those of the parent polymer sample. The polymeric chelates are found to be less stable than the parent polymer sample.

Synthesis and characterization of new polyetheramides

Abstract Polyetheramides (PEAs) are prepared by polycondensation of N,N′-diacetyl-o-tolidide with Bisphenol A, C, or F, phenolphthalein, resorcinol, catechol, hydroquinone, or 1,5- or 2,7-dihydroxynaphthalene or ethylene, butylene, propylene, diethylene, or triethylene glycol. The fusible and soluble oligomers are characterized. An attempt is made to bring out the relationship between various properties of PEAs and their structures.

Friedel-Crafts Polymers. 10. Polycondensation of 4-4′-Dichloromethlydiphenyl Ether with Phenol and Isomeric Cresols

Abstract Friedel-Crafts polycondensations of 4, 4′-dichloromethyldiphenyl ether (DDE) with phenol and isomeric cresols were carried out under different experimental conditions. The molecular weight of the polymer products was estimated by end group analysis, that of soluble products by VPO, and they were characterized by TGA and solution viscosity. DMF solutions of samples prepared from phenol and p- and m-cresols, but not those from o-cresol, showed abnormal viscosity behavior. However, the viscosity behavior of DMF-water solutions was normal. Abnormal vis-cisoty data of DMF solutions were correlated by an empirical relation. Curing of one fusible and soluble DDE-phenol polymer sample with hexamine was studied by measuring the percentage of cured material as a function of time at selected temperatures.

Friedel-Crafts Polymers. 9. Friedel-Crafts Polycondensation of 4,4′-Dichloroacetyldiphenyl Ether with Phenols

Abstract The Friedel-Crafts polycondensation of 4,4′-dichloroacetyldiphenyl ether (DADE) with phenol, o- and p-chlorophenols, and isomeric cresols was carried out in the presence of different molar proportions of AICI3 under different experimental conditions, proving that this dichloro monomer is a much weaker reagent than dichloromethyldiphenyl ether and p-xylylene dichloride in Friedel-Crafts polycondensation. The polyketoethers thus prepared from DADE under identical conditions are characterized by elemental analysis, IR spectral study, viscometric measurements in dioxane, and estimation of Mn by nonaqueous conducto-metric titration and by TGA in air. The polyketoethers are reduced by the Wolf-Krishner reaction. The properties of the reduced polyketoethers, which show no C[dbnd]0 bands in their IR spectra, are compared with those of their corresponding parent polyketoethers.

Synthesis, characterization and curing of bisphenol-f-furfural resin

Abstract Polycondensation of bisphenol-F with furfural has been carried out under various conditions. The resin samples have been characterized by spectral studies and viscometry and by estimation of number-average molecular weight. TGA of selected resin samples has been carried out. The curing of three resin samples has been studied by measurement of the amount of cured material as a function of time at specified temperatures. The kinetics of curing of one resin sample have been investigated by DSC.

Synthesis and characterization of copolymers from 4-halo(chloro, bromo) salicylic acid

Copolymers have been prepared by condensing a mixture of either 4-chloro or 4-bromosalicylic acid and any one of the comonomer like salicylic acid,p-hydroxybenzoic acid,p-aminosalicylic acid,p-aminobenzoic acid,p-cresol andp-halo(chloro, bromo)phenol with formaldehyde in the presence of 5M H2SO4. Copolymer composition of each of the copolymer has been estimated on the basis of halogen content and/or on the basis of results of non-aqueous titrations of the copolymer against standard sodium methoxide and/or tetra-n-butylammonium hydroxide. The IR spectral characteristics of copolymers have been noted. The viscometric and thermal studies of copolymers have also been carried out.