The basic raw materials for the chemical industry, which also means for polymer production, are mineral oil and natural gas. Mineral oil and natural gas resources are limited so that sooner or later they will be consumed. For this reason alternative, renewable raw materials for the chemical industry have become the object of intensive investigation all over the world. Some of the results of these investigations concerning renewable raw materials for the production of polymer materials are presented in this paper

The subject of the study was investigation of influence of substituent type on the properties of starch derivates in diluted solutions. Three samples were prepared: two anionic (carboxymethyl starch, CMS) and one cationic starch (KS). Starch derivates were synthesized in two steps. The first step was preparation of alkali starch by the addition of sodium-hydroxide to the starch dispersed in ethanol or water. In the second step, the required amount of sodium monocloracetate or 3-chloro-2-hydroxypropyl-threemethylamonium chloride was added to the obtained alkali starch in order to prepare CMS or KS, respectively. The degree of substitution of carboxymethyl starch was determined by back titration method, and the degree of substitution of cationic starch was determined by potentiometric titration. The degrees of substitution of prepared samples were: 0.50 (assigned as CMS-0.50) and 0.70 (assigned as CMS-0.70) for carboxymethyl starch and 0.30 (assigned as KS-0.30) for cationic starch. The properties of starch derivatives in dilute solutions were investigated by the methods of static and dynamic light scattering. Aqueous solutions of sodium chloride of different concentrations were used as solvent. The values of the mass average molar mass, MW, radius of gyration, Rg, and second virial coefficient, A2, were determined for all samples together with hydrodynamic radius, Rh. Molar masses of the samples were: 5.06×106, 15.4×106 and 19.2×106 g/mol for CMS-0.50, CMS-0.70 and KS-0.30, respectively. The samples, CMS-0.70 and KS-0.30 had similar molar mass and hydrodynamic radius, but radius of gyration of KS-0.30 was smaller then radius of gyration of CMS-0.70 at all sodium chloride concentrations. Consequently, ρ value for KS-0.30 was smaller then for CMS-0.70, as a result of more compact architecture of KS-0.30 then of CMS-0.70. Kratky graph confirmed this result. For all samples, radius of gyration and hydrodynamic radius decreased with increasing of sodium chloride concentration, but decrease of the radius was greater for CMS-0.50 then for other two samples due to its significantly lower molar mass. On the other hand, change of both radius of gyration and hydrodynamic radius of CMS-0.70 and of KS-0.30 with increasing sodium chloride concentration were similar. It can be concluded that the decrease of both Rg and Rh with increasing sodium chloride concentration in water depends far more on molar mass than on degree of substitution

The rheological properties of corn and potato starch concentrated aqueous solutions were investigated at 25ºC. The starches were previously dispersed in water and the solutions were obtained by heating of dispersions at 115-120ºC for 20 minutes. The solutions of potato starch were transparent, while the corn starch solutions were opalescent. The results of dynamic mechanical measurements showed that the values of viscosity, h, storage modulus, G′, and loss modulus, G″, of the corn starch solutions increased with the storage time. This phenomenon was not observed for the potato starch solutions. It was assumed that the increase of h, G′ and G″ is the result of starch solutions retrogradation. The potato starch solutions retrogradation did not occur probably because of the phosphates presence. The viscosity of 2 mass % corn starch solution is less than the viscosity of 2 mass % potato starch solution. By increasing the concentration of corn starch solution the gel with elastic behavior was formed. The corn starch solutions formed gel as early as at 4 mass % concentration, while potato starch solutions achieved the gel state at the concentration of 5 mass %. The value of exponent m (G′ and G″ µ wm) during the transition of potato starch solutions to gel is 0.414, which gives the fractal dimensions for corn starch of 2.10. The obtained value of fractal dimension corresponds to slow aggregation. The corn starch solutions with the starch concentrations higher than 4 mass % form weak gels. For these solutions the values of modulus in rubber plateau were determined. It was found that the modulus in rubber plateau increased with the concentration by the exponent of 4.36. Such high exponent value was obtained in the case when the tridimensional network is formed, i.e. when supermolecular structures like associates or crystal domains are formed