This work studies the effect of azobenzene dye Disperse Red 1 (DR1) doping and annealing on thermomechanical photomechanical properties poly(methyl methacrylate) (PMMA) fibers. The mechanical are measured as a function temperature, pump light intensity, polarization. We find that with DR1 increases stiffness glass transition temperature (Tg) PMMA Moreover, below Tg decreases Young’s modulus Tg....

Epoxy – Polysulfide copolymers without or with low amounts of epoxy in their structure have poor mechanical properties in oxidative curing system.To strengthen the mechanical properties of polysulfide elastomer inclusion of epoxy resin (Epon828) as hard segment was studied. FT-IR spectroscopy and rheometry were used to verify the formation of epoxy-polysulfide copolymer.  Results obtained f...

Density and hardness of glasses are known to increase upon both compression at the glass transition temperature (Tg) and ambient pressure sub-Tg annealing. However, a serial combination of the two methods does not result in higher density and hardness, since the effect of compression is countered by subsequent annealing and vice versa. In this study, we circumvent this by introducing a novel tr...

The crystallization process in Se100–xZnx glassy system is investigated using differential scanning calorimeters (DSC). The samples are prepared by conventional melt-quenching technique in the composition range 2 ≤ x ≤ 20 (at%). Nonisothermal measurements are carried out for different heating rates .The value of the glass transition temperature Tg the crystallization temperature Tc and the crys...

Dielectric relaxation and thermal expansion spectroscopy were made for thin polystyrene films in order to measure the temperature Tα corresponding to the peak in the loss component of susceptibility due to the α-process and the α-relaxation time τ as functions of film thickness d. While the glass transition temperature Tg decreases with decreasing film thickness, Tα and τ were found to remain a...

This paper investigated the effect of the amine-functionalized carbon nanotubes (CNTs) on the thermomechanical properties of CNT/epoxy nanocomposites. Mechanical stirring and ultra-sonication were utilized to uniformly disperse CNTs into the epoxy matrix. Non-functionalized and amine-functionalized CNTs with different weight percentages (wt. %) were mixed into the epoxy resin. Using standard te...

We investigated the kinetics of enthalpy recovery of several glass-forming polymers at temperatures significantly below the glass transition temperature (Tg) and for aging times up to one year. We find a double-step recovery at relatively low aging temperatures for the longest investigated aging times. The enthalpy recovered after the two-step decay approximately equals that expected by extrapo...

In this article, we present a universal relationship between the glass transition temperature Tg and the local glass structure. The derivation of the simplest expression of this relationship and some comparisons with experimental Tg values have already been reported in a recent letter. We give here the analytical expression of the parameter β of the Gibbs-Di Marzio equation and also new experim...

Bioactive glass formed on the base sample (Go) of 45S5 system with fluorine additives samples were prepared by melt quenching method. The glassy samples were subjected to DTA for determining temperatures at which phase transition occur. FTTR spectroscopy shed a light on the sorts of compounds, their structure as well as their functional groups. The crystalline nature of samples was confirmed by...

Mechanical relaxation behaviour of various natural volcanic glasses have been investigated in the temperature range RT − 1000C using special low frequency flexure (f≈0.63Hz) pendulum experiments. The rheological properties complex Young’s modulus M⋆(ω, τ) and internal friction Q−1(ω, τ) have been studied from a pure elastic solid at room temperature to pure viscous melt at log(η[Pas]) = 8. The ...