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EFFECT OF IONIC CROSSLINKING ON DENSITY OF HYDROGEL CHITOSAN MEMBRANES

100%

Gierszewska-Drużyńska M. , Ostrowska-Czubenki J. , Kwiatkowska A.

tom 18

nr 18

49-57

Ionically crosslinked chitosan membranes were prepared and their density was determined using modified pycnometer method. High molecular compound: sodium alginate (NaAlg) and low molecular compounds: pentasodium tripolyphosphate (TPP) and trisodium citrate (CIT) were used as ionic crosslinkers of chitosan. As a reference liquid n-heptane solution was chosen. It was found out that density of modified chitosan membranes is strongly affected by the type of ionic crosslinker and membrane preparation conditions

Synthesis and characteristics of chemically modified chitosan membranes with sulfuric acid

86%

Ostrowska-Czubenko J. , Pieróg M.

Polish Journal of Applied Chemistry

2009

tom Vol. 53, nr 2

155-160

Chemically modified chitosan membranes were obtained by treatment of chitosan membranes with sulfuric acid. The effect of chemical modification conditions on molecular and supcrmolecular structure and some physicochemical properties of synthesized membranes were studied using FTIR spectroscopy, X-ray diffraction method, SEM and elemental analysis. FTIR spectra of unmodified and modified chitosan membranes were compared and conclusions concerning the formation of ionic crosslinks between protonated amine groups of chitosan and sulfate anions were drawn out. X-ray analysis indicates that strong interactions between chitosan -NH3~ groups and SO42' ions influence chitosan membrane crystallinity.

Synthesis and characterization of star-shaped poly(ε-caprolactones)s

86%

Łukaszczyk J. , Jelonek P. , Trzebicka B.

Polish Journal of Applied Chemistry

2009

tom Vol. 53, nr 2

147-153

A scries of star-shaped hydroxyl-terminated poly(e-caprolactone)s (SPCLs), with various number of arms and their lengths, was synthesized. SPCLs were synthesized via the ring-opening polymerization of ?-caprolactonc (CL) carried out in the presence of multifunctional alcohol as an initiator and stannous octoate (SnOct2) catalyst. Variation in the number of arm was achieved by using alcohols having 3 (glyccrin), 4 (pcntaerithritol), and 6 (dipcntacrithritol) hydroxyl group. Various arm lengths were obtained by controlling monomer to hydroxyl group molar ratio ([CL]:[OH]). Expected chemical structure of SPCLs was confirmed by NMR and IR spectroscopy. Molar mass of polymers was calculated from 'H NMR and determined by means of SEC-MALLS analysis. Thermal properties of polyesters were investigated using differential scanning calorimetry (DSC).