Thermo-mechanical and adhesion properties of polymers and composites as affected by nature of epoxy isocyanate binders

The differential scanning calorimetry method was used to study kinetics of cyclo-polymerization of epoxy resins with di- and polyisocyanates of different nature. To reduce a temperature interval in which the reaction between epoxy novolac resin and isophoronodiisocyanate progresses, efficient catalysts — the complexes of zinc dichloride with imidazole and tributylphosphate — were proposed. Highly heat-resistant polymers and composites were obtained due to cyclic oxazolidones and isocyanurates contained in their structure. Adhesion capacity of epoxy isocyanate compositions to aluminium and its alloys was studied as well.

Study of Interstitial Impurities Influence on Properties of Titanium Alloy Ti-5Al-5V-5Mo-3Cr-1Zr

The effect of different interstitial impurities content (oxygen, carbon) on β - transus temperature and complex of properties in the heat-strengthened condition of the Ti-5Al-5V-5Mo-3Cr-1Zr (VST55531) titanium alloy has been studied. The possibility of determining alloy β - transus temperature by the differential scanning calorimetry method with accuracy comparable with the test quenching method is shown in this paper. It is shown that under identical aging regimes an increase of oxygen content from 0.176 to 0.25 wt.% and carbon content from 0.009 to 0.025 wt.% in VST55531 alloy results in higher strength, plastic characteristics and lower ductility, toughness characteristics, especially those which related to the crack propagation.

KINETIC STUDY OF SYNTHESIS REACTION OF LIGNOSULFONATE USING ISOTHERMAL DIFFERENTIAL SCANNING CALORIMETRY METHOD

The kinetics of lignin methylsulfonation were studied in solution by using differential scanning calorimetry (DSC) techniques under an isothermal program, at 55, 65, 75 and 85°C, respectively. It was found that activation energy, Eα = 41.26 kJ/mol, and preexponential factor A was 1.85×103 s-1.

Using the Ozawa method to study the thermally initiated curing kinetics of vinyl ester resin

1,1-Bis(t-hexylperoxy)-3,3,5-trimethyl cyclohexane was introduced to thermally initiate the curing of vinyl ester resin, and a dynamic differential scanning calorimetry method was applied to investigate the thermally initiated curing procedures.