Synthesis of conducting PPy/pTHF copolymers

Living polytetrahydrofuran (pTHF) was terminated with the potassium salt of pyrrole to yield polymers with pyrrole end groups. Copolymerization of THF and pyrrole with short and long I,THF segments was achieved by constant potential electrolysis. Syntheses of the block copolymers were performed using tetrabutylammonium tetrafluoroborate, sodium pel:chlorate, and sodium p-toluenesulfonate as the supporting electrolytes. Characterization of the block copolymers were based on scanning electron microscopy, differential scanning calorimetry, thermal gravimetry analysis, cyclic voltammetry, and FTIR studies. No significant effect of the chain length on the properties of the copolymers was observed; however, use of different dopants resulted in different thermal and electrochemical behaviors, surface morphologies, and conductivities. (C) 1999 John Wiley & Sons, Inc

Conducting copolymers of polypyrrole/polytetrahydrofuran

Bifunctional living polytetrahydrofuran (PTHF) was terminated with potassium salt of pyrrole to yield polymers with electrochemically active end groups. These polymers were employed in the second stage to obtain conducting polypyrrole/polytetrahydrofuran block copolymers with short and long polytetrahydrofuran segments by potentiostatic anodic polymerization of pyrrole in different electrolytic media. Syntheses of block copolymers were achieved in media where tetrabutylammonium fluoroborate, sodium perchlorate and sodium p-toluenesulfonate were used as the supporting electrolytes. Characterizations were based on DSC, TGA, SEM, FTIR and CV analyses. No significant effect of the chain length of polytetrahydrofuran segments on the properties of the copolymers was observed; however, thermal, electrochemical behaviors, and surface morphologies of the films were greatly affected by the supporting electrolytes

Immobilization of invertase in conducting polypyrrole polytetrahydrofuran graft polymer matrices

Four different polypyrrole/polytetrahydrofuran/invertase electrodes were constructed by the entrapment of invertase in conducting polymer matrices via electropolymerization. Immobilization of the enzyme was achieved by the application of a 1.1 V constant potential to a platinum electrode for 30 min in a solution containing 0.01 M pyrrole, 0.4 mg/ml invertase and 0.4 mg/ml sodium dodecyl sulphate. Performance of each electrode was optimized by examining the effects of pH and temperature on the properties of the electrodes. The changes in the maximum velocity of the reaction and variation of Michaelis-Menten constant upon immobilization were investigated. The enzyme immobilized in those matrices retained its activity for several months. (C) 1999 Elsevier Science S.A. All rights reserved