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Modyfikacje nienasyconych estrów skrobi aminami i tiolami

Stawski D.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

2005

z. 61

45-56

W pracy zsyntezowano estrowe pochodne skrobi (akrylan i metakrylan) metodą międzyfazowej estryfikacji skrobi odpowiednimi chlorkami kwasowymi. Zbadano nieopisaną dotąd w literaturze nukleofilową addycję amin pierwszo- i drugorządowych oraz tioli do grup winylowych akrylanu i metakrylanu skrobi. Określono wpływ temperatury, rodzaju aminy, stopnia podstawienia i rodzaju rozpuszczalnika na kinetykę addycji do akrylanu skrobi. Porównano odporność termiczną skrobi, jej pochodnej estrowej i aminowej. Wykazano działanie antyelektrostatyczne oraz sorpcyjne trzeciorzędowych i czwartorzędowych pochodnych skrobi.

Ester derivatives of starch, which contain reactive vinyl bonds, such as starch acrylate and methacrylate, were synthesized. The synthesis of these compounds, which had not been sufficiently described as yet, was carried out at a low temperature (about -7°C) by the interfacial esterification of starch with appropriate acid chlorides. Under these conditions no degradation of the polysaccharides chain and no side reactions of vinyl bonds take place. Based on the results of elementary analysis and FTIR, H-NMR and C-NMR spectra, the chemical composition of the esterification products has been confirmed. The second stage of this study was intended for detailed investigation of the so far unreported reactions of nucleophilic addition of primary and secondary amines and dodecanitiole to vinyl groups of starch acrylate and methacrylate under the conditions of pseudo-first order reaction. Based on the obtained results it has been found that the effect of temperature on the reaction rate is consistent with the general assumption of chemical kinetics. The calculated activation energies for the secondary amine addition ranged from 13.2 to 24.2 kJ/mol and those for primary amines from 11.7 to 13.0 kJ/mol. A slight effect of THF and dioxane on the addition kinetics was also observed, while the reaction course was slower in DMSO, which is characterized by a considerably higher dielectric constant. On the other hand, a clear decrease in the constants of pseudo-first order reaction rates was observed in the case of primary and secondary amines with different lengths of aliphatic chain. The presence of amine and thiol groups in the products of addition was confirmed by the methods of FTIR, H-NMR and C-NMR. On the basis of the results of thermogravimetric analysis of starch and products of its modification it has been found that the thermal resistance of starch acrylate is slightly higher than that of initial starch and the degree of substitution with ester groups exerts no significant influence on their thermal stability. The starch derivatives containing tertiary amine groups and anionic groups were successfully used as an antistatic finish for polyester fabrics. The use of N,N-dipropylaminepropionate of starch as a sorbent of copper ions has been also investigated. The results obtained show that the amine derivatives of starch can combine about 1.5 mmole of Cu2+/g sorbent after 10 h.