TiO 2 nanoparticles, obtained by acid catalyzed hydrolysis of titanium isopropoxide, were surface modified by three gallic acid esters with different hydrophobic part length: octyl, decyl and lauryl gallate, and then used to prepare TiO 2 /epoxy nanocomposites. The characterization of the surface modified TiO 2 nanoparticles was performed by FTIR and UV-Vis spectroscopy. The influence of different gallic acid esters and content of modified TiO 2 nanoparticles on the glass transition temperature (Tg), rheological, barrier and mechanical properties of the nanocomposites was investigated by DSC, DMA, water vapor permeability test and König pendulum. The presence of the surface modified TiO 2 nanoparticles in epoxy resin caused the increase of Tg and decrease of the water vapor permeability. However, the length of the nonpolar gallate part showed no effect on Tg of the synthesized nanocomposites, while the increase of the nanofiller content resulted in the increase of Tg. With increasing the hydrophobic part chain length of gallate ligand, the water vapor transmission rate decreased, while the hardness of the nanocomposites did not change.

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

Twelve modified dithiocarbamates and a thiuramdisulfide used for the initiation of methyl methacrylate (MMA) polymerization were synthesized in this study. The polymerization of MMA was followed by determine the yield and molar mass of the obtained PMMA as a function of polymerization time. Four of the synthesized dithiocarbamates S-benzyl-N,N-dibenzyldithiocarbamate, S-allyl-N,N-dibenzyldithiocarbamate S-benzyl-N,N-diisobutyldithiocarbamate and S-benzoyl-N,N-diisobutyldithiocarbamate, as well as N,N,N',N'-tetrabenzylthiuramdisulfide acted as iniferters. They were active as the initiators of the photo and/or thermally initiated radical polymerization of MMA in bulk and inert solvents (benzene and toluene). S Benzyl - N,N - dibenzyldithiocarbamate can be successfully used for the initiation of MMA polymerization in a polar solvent such as dimethylacetamide

Carboxymethyl starch was synthesized by the esterification of starch with monochloroacetic acid in ethanol as a reaction medium. Three samples of carboxymethyl starch having different degrees of substitution were prepared. The influence of temperature on the viscosity of concentrated carboxymethyl starch solutions, as well as the dynamic-mechanical properties of the concentrated solutions were investigated. The activation energy of viscous flow was determined and it was found that it decreased with increasing degree of substitution. The results of the dynamic-mechanical measurements showed that solutions of starch and carboxymethyl starches with higher degrees of substitution behave as gels. Values of the storage modulus in the rubbery plateau were used to calculate the molar masses between two points of physical crosslinking, the density of crosslinking and the distance between two points of crosslinking