cross-linking

The vulcanization process of elastomeric blends based on chlorinated aromatic nitrile-butadiene rubber (SKN-40M) has been studied in the present work. The structural parameters (molecular weight, plasticity, rigidity, number of network chains, cross-linked molecules) in thermovulcanizates were investigated on an example of nitrile-butadiene rubber blend with polyvinyl chloride using viscometry and the sol-gel process.

Melamine formaldehyde oligomers with peroxy groups (MFOP) have been synthesized based on melamine or urea and melamine in the presence of tert-butyl peroxymethanol or tert-butyl hydroperoxide. Zinc oxide was used as a catalyst. The effect of peroxide nature, ratio of the starting components and process time on the characteristics and yield of MFOP has been studied. The structure of the synthesized MFOP was confirmed by IR- and PMR-spectroscopy. The chemistry of the cross-linked structures formation was studied.

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.

Cross-linked polymeric and nanocomposite films based on poly(2-ethyl-2-oxazoline) and modified mineral nanoparticles of hydroxyapatite and silica have been obtained via radical cross-linking initiated by peroxide containing reactive copolymers. The influence of temperature and additional cross-linking agents on the peculiarities of curing process has been studied. The obtained results reveal that at high temperatures the dependence of film gel-fraction values on time has the extremal character.

The series of reactive peroxide macroinitiators (RC) based on acryl amide (AcAm), butyl methacrylate (BMA), maleic anhydride (MA) and peroxidic monomer 5-ter-butylperoxy-5-methyl-1-hexene-3-yne (PM), which can be used for biocompatible polymer cross-linking, were synthesized via radical copolymerization in organic solvent.

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 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.

Carboxy-containing peroxy oligomer (CPO) has been synthesized via the reaction of peroxy derivative of ED-24 epoxy resin with free peroxy and epoxy groups with adipic acid in the presence of benzyl triethylammonium chloride. The effect of catalyst amount, reaction temperature and process time on the reaction rate has been determined. The effective rate constants and activation energies have been calculated. CPO synthesis procedure has been developed. CPO structure has been confirmed by chemical and IR-spectroscopic analyses.