gel-fraction

The paper represents the results of the investigation of the formation of a polymeric matrix of hydrogel due to the structuring of polyacrylamide using its reactive polymeric derivative – poly-N-(hydroxymethyl) acrylamide. Research determined zones of optimum conditions of synthesis and characterized hydrogel depending on pH of media, the ratio between the concentration of prepolymers, and time of synthesis.

Physico-mechanical properties of the products based on filled epoxy-oligomeric mixtures composed of Epidian-5 epoxy resin, oligoesteracrylate TGM-3 and monoperoxide derivative of Epidian-6 epoxy resin (PO) have been investigated. CaCO3 was used as a filler and polyethylene polyamine was a curing agent. The effect of PO and CaCO3 on the gel-fraction content and physico-mechanical properties was examined. Using a scanning electron microscopy (SEM) the morphology of the samples has been studied.

The processes of receiving and the properties of thin polymer pellicles of network structure on the basis of reactionary copolymers were researched. It was shown that the cross linked network structures are formed as a result of the reactions of peroxide groups presented in polymer structure as well as due to the interactions of anhydride groups with bifunctional alcohols. The optimal conditions and component correlation for the formation of network three-dimensional structures with high linking level were determined.

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. 

Cross-linking of epoxy-oligomeric mixtures based on ED-20 industrial epoxy dianic resin and TGM-3 oligoesteracrylate in the presence of fluorine-containing peroxy oligomers has been studied. Oligomers used for the cross-linking have been obtained via chemical modification of peroxy derivative of ED-24 epoxy resin with alcohols-telomers by general formula HOCH2–(CF2–CF2)nH, where n is 3 or 4. The thermal stability of peroxy groups in the initial material, fluorine-containing peroxy oligomers and stability of cross-linked films have been examined using derivatographic methods.

The possibility of chemical modification of ED-24 epoxy resin peroxy derivative (PDER) by C9H4F16O fluorine-containing alcohol-telomer (FAT-C9) has been shown using 18-Crown and ZnCl2 catalytic system. The effect of catalyst amount, temperature and process time on the reaction rate has been studied. New peroxy oligomer containing fluorine atoms (FPO) has been synthesized and characterized. The FPO structure has been confirmed by IR-spectroscopy.

New epoxy resins with fluorine atoms have been synthesized via chemical modification of dianic epoxy resin with fluorine-containing alhocols-telomers C7, C9 and C13, using benzyltriethylammonium chloride and KOH as a catalyst system. Their characteristics have been examined. The structure of synthesized products has been confirmed by IR-spectroscopy. It has been shown that new epoxy resins may be used as active plasticizers for industrial epoxy resin.

Crosslinking of epoxy-oligomeric mixtures has been studied at room temperature and at heating to 383, 403 and 423 K for 15, 30, 45, 60 and 75 min in the presence of polyethylenepolyamine. The mixtures consist of industrial ED-20 epoxy resin, oligoesteracrylate TGM-3 and carboxy-containing derivative of ED-24 epoxy resin. The effect of mixture composition, temperature and process time on the gel-fraction content and hardness of polymeric films has been examined. Using IR-spectroscopy the chemism of network formation has been determined.

The reaction between novolac phenol-formaldehyde resin and glycidylmethacrylate has been studied in the presence of potassium hydroxide and the synthesis procedure of phenol-formaldehyde resin with unsaturated side bonds has been suggested. The effective rates and activation energy of the mentioned reaction have been calculated. The structure of synthesized resin was confirmed by IR-spectroscopy. The synthesized resin may be used as active component of polymeric blends based on ED-20 industrial epoxy resin, its peroxy derivative (PO) and TGM-3 oligoesteracrylate.

The possibility of epoxy resin carboxy-containing derivative (CDER) obtaining has been studied on the basis of dianic epoxy resin ED-24 and adipic acid (AA). The synthesized CDER contains epoxy and carboxy groups at the same time. Used catalysts were benzyltriethylammonium chloride (BTEACh); 1,4-diazobicyclo[2,2,2]octane; N,N-dimethylaminopyridine; 18-Crown-6, potassium hydroxide, triethylamine and 18-Crown-6+ZnCl2 catalytic system. The effect of the catalyst nature and amount, reagents ratio, process temperature and time on the reaction proceeding between ED-24 and AA has been determined.