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Covalent-bonded immobilization of lipase from burkholderia cepacia onto two poly(phenylene sulfide) (PPS) dendrimers with different generations (two and three) was achieved using carbodiimide as a coupling reagent. The hydrolysis activity of olive oil to fatty acid was studied on enzyme-immobilized PPS dendrimers. Enzyme activity was proportional to the enzyme loading, and highest recovered activity was obtained at the medium enzyme loading for both G2 and G3 dendrimers. The immobilization improved the optimum pH and caused the temperature range to widen. Immobilization of enzyme has enhanced the thermal stability of enzyme activity in comparison with free enzyme. The immobilized enzyme as a biocatalyst for batch hydrolysis of olive oil retained 80 approximately 90% activity even after 20 times of recycling. This retention of activity after recycle is very valuable and powerful in enzyme technology. The present noteworthy and vital availability on enzyme reaction of the covalently bonded immobilized lipase on dendrimer came from the structure of dendrimer with a large number of functional terminal groups, which are easily available for immobilization of many lipases at the situation keeping reactive enzymes on the surface of dendrimer.

Poly(phenylene sulfide) dendrimers up to fourth generation were synthesized by divergent method from 1,3,5-tris(4-chloro-phenylene-1-thio)benzene. All the dendrimers are soluble in polar organic solvents at room temperature. The chemical structures at the synthesis steps were confirmed by spectroscopic method. X-Ray diffraction study revealed that all dendrimers are semi-crystalline in nature. Carboxy focal poly(phenylene sulfide) dendrons were synthesized up to second generation by divergent method from 3,5-dichlorobenzoicacid. On surface pressure-area iso- therm at air-water interface, third generation poly(phenylene sulfide) dendrimer displayed hysteresis. Its occupied sur- face area was smaller than the calculated values as well as a case of second generation poly(phenylene sulfide) dendron. Atomic force microscopic images of their LB films presented accumulation and aggregation of molecular layers. On the other hand, adsorption films of dendrimer and dendron were fundamentally monolayer. Molecular arrangements in the LB and adsorption films and the driving forces of the film formation were discussed.

The synthesis of poly(thio- 1,4-phenylene) (PPS) at room temperature by the reaction of diphenyl disulfide with potassium persulfate (K2S2O8) in non-basic solvents, in the presence of trifluoromethanesulfonic acid, is reported. The reaction in chlorinated solvents, such as dichloromethane and tetrachloroethane, resulted in partial oxidation of sulfide to sulfoxide and sulfone. On the other hand, the polymerization proceeded well in nitrobenzene and the PPS formed was free of branches, crosslinks and thianthrene units. The molecular weight of the polymers formed in different solvents were in the range 2000–8000. The reaction proceeded under identical conditions with bis(2,6-dimethylphenyl) disulfide as well, but the polymer yield was lower.