Search

The sulphonation of commercially available PEEK in powder form (Gatone™, Gharda Chemicals Limited, India) was carried out using conc. H2SO4 under different reaction conditions. The duration of reaction was varied from 3-5 h, polymer concentration 4-10% (w/v) and temperature 35-50°C. Structural characterisation of sulphonated polymers was done by elemental analysis, FT-IR and1H-NMR spectroscopy. The degree of sulphonation as calculated from1H-NMR and elemental analysis (S-content) was found to be in the range of ~ 50-80%. Multistep mass loss was observed in thermogravimetric traces (recorded in N2 atmosphere). The first step (50-225 ± 25°C) was due to loss of moisture (1-10%) and second step (250-425 ± 25°C) has been attributed to volatilization of SO3 from the sulphonic group. The backbone degradation takes place above 450°C. The mechanical properties and proton conductivities of various sulphonated samples was also evaluated. [ABSTRACT FROM AUTHOR]

Structurally different poly(arylene ether sulphone) (PES) copolymers were synthesized by reacting stoichiometric amount of dichlorodiphenyl sulphone (DCDPS) with bisphenols. The molar ratio of bisphenol-A and phenolphthalein (ESP)/hydroquinone (ESH)/resorcinol (ESR) was varied to prepare nine copolymer samples. Structural characterization was done by FT-IR and 1H-NMR studies. The initial decomposition temperature as well as temperature of maximum rate of mass loss in ESR and ESH copolymers were similar and a marginal decrease in these decomposition temperatures were observed by increasing the isopropylidine units in the backbone. High char residue at 800°C was observed in polymers having high content of phthalein units. [ABSTRACT FROM AUTHOR]

Reviews the synthesis, characterization, physicochemical, thermal and mechanical properties of polymeric binders containing pendant azido group. Preparation of azido polymers; Physical properties of azido polymers; Thermal behavior; Photodecomposition of the polymers.

Disusses the effect of structure on thermal behavior of homopolymers and copolymers of itaconimides. Synthesis of itaconimides; Characterization of itaconimides; Polymerization; Modifications of itaconimides polymers.

Examines the state of the art of the unsaturated polyester (UP) thermoset resins. Characterization of UP resins; Classification of UP resins; Synthesis of UP by the reaction of unsaturated and saturated dibasic acids with dihydric alcohols.