polymer films

Cross-linked polymer films based on polyvinyl alcohol and polyacrylamide have been prepared via radical cross-linking initiated by peroxide containing reactive copolymers. The influence of temperature, nature and concentration of cross-linking agents onto gel-fraction value and properties of polymer films has been studied. Obtained cross-linked polymer films are characterized by improved physico-mechanical properties that depend on the content of peroxide containing copolymer and on the presence of additional cross-linking agent.

The effect of filling on water uptake has been studied for coatings based on aqueous dispersion Acronal-290D and pigment part consisting of titanium dioxide and calcium carbonate. It was found that an increase in the pigment volume concentration is accompanied by an increase in the rate of water absorption, but the maximum value of water uptake is characterized by a minimum near the critical pigment volume concentration.

Crosslinking of epoxy-oligoesteric mixtures composed of ED-20 dianic epoxy resin and TGM-3 oligoesteracrylate has been studied in the presence of dioxydiphenylpropane diglycidyl ether modified with adipic acid (DCDER). Crosslinking was carried out at room temperature and while heating at 383, 403 or 423 K using polyethylene polyamine as a hardener. The procedure of DCDER synthesis has been developed. The structural changes were controlled by determining film hardness and gel-fraction content. The chemistry of films formation was confirmed by IR-spectroscopy. 

The present paper describes a simple circuit for construction of a cyclic voltage generator, which can be used in electrochemical synthesis of conducting polymer films like polyaniline(PANI), polythiophene, polypyrrol etc. The circuit consists of a clock generator; its frequency is converted into digital voltage which is further converted to analog form using digital to analog converter (DAC). This analog voltage, after boosting, is used as a source of voltage in the synthesis of conducting polymer.

Through the process of modification of chitosan films obtained from solutions in acetic acid, the possibility of obtaining iodine polymer films with controlled release of iodine has been shown.