Thermo-Mechanical Analysis of Chosen Epoxy Resins Used in Aviation Technology

摘要

In this paper the results of storage modulus (E'), loss modulus (E") and damping parameter tan(δ)=E"/E' of epoxy resins Epidian 57 and L285 with curing agents Z1 and LH285, respectively are presented. In addition to this the stress-strain and thermal expansion characteristics of Epidian 53, 57 and L285 were obtained experimentally in order to compare Dynamic Mechanical Analysis (DMA) results. Temperature range of DMA investigations using Netzsch (Germany) DMA 242C analyzer was from -120°C to +110°C at the heating rate of 1 K/min with frequency of {0.1, 1, 10} Hz, respectively. Netzsch DIL 402C dilatometer was used to study the thermal expansion of the tested samples within temperature range from 30°C to 80°C at 1 K/min of heating and cooling rates, respectively and Huang TA computer servo control material testing machine HT-2402 was applied to determine the stress-strain characteristics. Measurements of sample elongation △L and physical α~* were performed twice in heating and cooling cycles. The glass transition temperature T_g determined from maximum of tan(δ) curve at f = 1 Hz was equal to 76.7°C for E57 and 87.2°C for L285. It has been observed durable deformed shape of L285 sample with deflection in the middle about 5 mm just after finishing the DMA first run of heating which significantly affected DMA results during the second run of heating.